Linux內核使用浮點運算問題

時間 2020-06-22

原文原文鏈接

　　上一篇博文中電池溫度檢測原理和示例代碼，因爲驅動要使用對數函數而從網上參看一個實現html

double ln(double a) { int N = 15; int k,nk; double x,xx,y; x = (a-1)/(a+1); xx = x*x; nk = 2*N+1; y = 1.0/nk; for(k=N;k>0;k--) { nk = nk - 2; y = 1.0/nk+xx*y; } return 2.0*x*y; }

尷尬的是當時內核不支持浮點運算因此停滯了，時間緊迫只能折中先列出各個溫度和電壓對應表，經過查表方式處理，今天着重瞭解一下爲什麼內核使用浮點運算「前世此生」linux

1、早期處理器

　　因爲早期處理器硬件壓根沒有浮點運算功能，因此編譯器天然不會編譯出對應指令，可是確實有須要的場景，不管應用程序仍是內核驅動，全部出現了浮點模擬器，具體配置在： c++

　　原理很簡單，就是編譯器對浮點運算代碼仍是編譯對應「指令」，當運行時ARM指令集沒有該「指令」從而致使指令異常，而後在異常處理函數中調用浮點模擬器函數計算該「指令」並返回結果sass

優勢不言而喻是可以支持浮點需求場景，對應用程序仍是驅動都透明；缺點也顯而易見，這種「指令異常」方式會增長系統無效負載，影響中斷響應時間等。app

　　Linus Torvalds認爲內核不該該進行浮點運算，因此後來的內核版本menuconfig我沒看到有這個浮點模擬器，相比於內核應用程序使用到浮點運算需求更大，總不能「躺槍」也不能用吧？ide

因此就出現了個軟浮點庫，編譯器在編譯應用程序發現這是一條浮點運算時會用函數進行替代！好比上面ln()函數的x = (a-1)/(a+1); 減法加法最後相除都調用函數解決！函數

x = (a-1)/(a+1); 反彙編以下： 84c8: e3a0300f mov r3, #15 84cc: e50b3020 str r3, [fp, #-32]  ; 0xffffffe0 84d0: e14b03dc ldrd r0, [fp, #-60]  ; 0xffffffc4 84d4: e3a02000 mov r2, #0 84d8: e3a035ff mov r3, #1069547520 ; 0x3fc00000 84dc: e2833603 add r3, r3, #3145728        ; 0x300000 84e0: eb000188 bl 8b08 <__aeabi_dsub> 84e4: e1a02000 mov r2, r0 84e8: e1a03001 mov r3, r1 84ec: e1a04002 mov r4, r2 84f0: e1a05003 mov r5, r3 84f4: e14b03dc ldrd r0, [fp, #-60]  ; 0xffffffc4 84f8: e3a02000 mov r2, #0 84fc: e3a035ff mov r3, #1069547520 ; 0x3fc00000
    8500:       e2833603        add     r3, r3, #3145728        ; 0x300000
    8504:       eb000180        bl      8b0c <__adddf3>
    8508: e1a02000 mov r2, r0 850c: e1a03001 mov r3, r1 8510: e1a00004 mov r0, r4 8514: e1a01005 mov r1, r5 8518:       eb000301        bl      9124 <__aeabi_ddiv>

　　這很好理解，畢竟應用使用浮點頻率較高，靠浮點模擬器總產生異常應用態切成內核態處理完再返回用戶態，太耗性能了。性能

2、現代處理器

　　現代處理器硬件已經支持浮點運算，並且做爲一個組件對待，可選配，根據需求和方案選型處理器時評估是否須要硬件支持。在STM系列浮點硬件單元叫作FPU（float process unit）吧，測試

ARM中歸屬協處理器那邊的。因此咱們知道若是要使用硬件浮點的話，須要知足三個條件：ui

1. 硬件要有浮點運算單元 2. 軟件要配置使能硬件浮點，好比Linux內核要選中下面配置（主要設置協處理器）

3. 編譯器指定-mfloat-abi=softfp 或-mfloat-abi=hard 編譯浮點指令而不是用函數替換！

　　一樣是上面ln()函數的x = (a-1)/(a+1); 採用了硬浮點指令後反彙編代碼以下：

x = (a-1)/(a+1); 反彙編以下：

　　84b0:    ed1b6b0d     vldr    d6, [fp, #-52]    ; 0xffffffcc 84b4: ed9f7b33 vldr d7, [pc, #204]    ; 8588 <ln+0xf0> 84b8: ee365b47 vsub.f64 d5, d6, d7 84bc: ed1b6b0d vldr d6, [fp, #-52]    ; 0xffffffcc 84c0: ed9f7b30 vldr d7, [pc, #192]    ; 8588 <ln+0xf0> 84c4: ee366b07 vadd.f64 d6, d6, d7 84c8: ee857b06  vdiv.f64 d7, d5, d6

3、示例代碼

　　咱們分別寫個應用程序和驅動程序，且分別用軟浮點和硬浮點測試其性能

1.應用程序

　　代碼以下：

/* arm-none-linux-gnueabi-gcc -mfloat-abi=soft application_test.c -lrt -o soft.bin * arm-none-linux-gnueabi-gcc -mfloat-abi=softfp application_test.c -lrt -o softfp.bin * arm-none-linux-gnueabi-gcc -mfloat-abi=hard application_test.c -lrt fail!! */ #include<stdio.h> #include<time.h>

double ln(double a) { int N = 15; int k,nk; double x,xx,y; x = (a-1)/(a+1); xx = x*x; nk = 2*N+1; y = 1.0/nk; for(k=N;k>0;k--) { nk = nk - 2; y = 1.0/nk+xx*y; } return 2.0*x*y; } int main() { int t1; double Rt, Vadc; struct timespec time_start={0, 0},time_end={0, 0}; clock_gettime(CLOCK_PROCESS_CPUTIME_ID, &time_start); /* 根據採樣電壓反推熱敏電阻的溫度 */
    for(Vadc=1; Vadc<1800; Vadc++) { Rt = Vadc * 47000 / (1800-Vadc); t1=1/(ln(Rt/10000)/3950+1/298.15)-273.15; } clock_gettime(CLOCK_PROCESS_CPUTIME_ID, &time_end); printf("start time %ld s,%ld ns\n", time_start.tv_sec, time_start.tv_nsec); printf("end time %ld s,%ld ns\n", time_end.tv_sec, time_end.tv_nsec); printf("duration:%ld s %ld ns\n", time_end.tv_sec-time_start.tv_sec, time_end.tv_nsec-time_start.tv_nsec); printf("%.10fmv = %d\n", Vadc, t1); return 0; }

反彙編能夠看出硬浮點直接指令，軟浮點是用函數替換並且是靜態連接，致使bin文件比較大

/* arm-none-linux-gnueabi-objdump -d soft.bin > objdump_soft.txt */ soft.bin: file format elf32-littlearm Disassembly of section .init: 00008388 <_init>: 8388: e92d4008 push {r3, lr} 838c: eb000024 bl 8424 <call_gmon_start>
    8390: e8bd8008 pop {r3, pc} Disassembly of section .plt: 00008394 <.plt>: 8394:    e52de004     push    {lr}        ; (str lr, [sp, #-4]!) 8398:    e59fe004     ldr    lr, [pc, #4]    ; 83a4 <_init+0x1c> 839c: e08fe00e add lr, pc, lr 83a0: e5bef008 ldr pc, [lr, #8]! 83a4: 00009168     .word    0x00009168 83a8: e28fc600 add ip, pc, #0, 12 83ac: e28cca09 add ip, ip, #36864    ; 0x9000 83b0: e5bcf168 ldr pc, [ip, #360]!    ; 0x168 83b4: e28fc600 add ip, pc, #0, 12 83b8: e28cca09 add ip, ip, #36864    ; 0x9000 83bc: e5bcf160 ldr pc, [ip, #352]!    ; 0x160 83c0: e28fc600 add ip, pc, #0, 12 83c4: e28cca09 add ip, ip, #36864    ; 0x9000 83c8: e5bcf158 ldr pc, [ip, #344]!    ; 0x158 83cc: e28fc600 add ip, pc, #0, 12 83d0: e28cca09 add ip, ip, #36864    ; 0x9000 83d4: e5bcf150 ldr pc, [ip, #336]!    ; 0x150 83d8: e28fc600 add ip, pc, #0, 12 83dc: e28cca09 add ip, ip, #36864    ; 0x9000 83e0: e5bcf148 ldr pc, [ip, #328]!    ; 0x148 Disassembly of section .text: 000083e8 <_start>: 83e8: e3a0b000 mov fp, #0 83ec: e3a0e000 mov lr, #0 83f0: e49d1004 pop {r1} ; (ldr r1, [sp], #4) 83f4: e1a0200d mov r2, sp 83f8: e52d2004 push {r2} ; (str r2, [sp, #-4]!) 83fc: e52d0004 push {r0} ; (str r0, [sp, #-4]!) 8400:    e59fc010     ldr    ip, [pc, #16]    ; 8418 <_start+0x30>
    8404:    e52dc004     push    {ip}        ; (str ip, [sp, #-4]!) 8408:    e59f000c     ldr    r0, [pc, #12]    ; 841c <_start+0x34> 840c: e59f300c ldr r3, [pc, #12]    ; 8420 <_start+0x38>
    8410:    ebffffe7     bl    83b4 <_init+0x2c>
    8414:    ebffffef     bl    83d8 <_init+0x50>
    8418:    00009328     .word    0x00009328 841c: 00008628     .word    0x00008628
    8420:    00009260     .word    0x00009260

00008424 <call_gmon_start>: 8424:    e59f0014     ldr    r0, [pc, #20]    ; 8440 <call_gmon_start+0x1c>
    8428:    e59f2014     ldr    r2, [pc, #20]    ; 8444 <call_gmon_start+0x20> 842c: e08f3000 add r3, pc, r0 8430: e7933002 ldr r3, [r3, r2] 8434:    e3530000     cmp    r3, #0
    8438: 012fff1e bxeq lr 843c: eaffffdf b 83c0 <_init+0x38>
    8440:    000090d8     .word    0x000090d8
    8444:    00000020     .word    0x00000020

00008448 <__do_global_dtors_aux>: 8448:    e59f3010     ldr    r3, [pc, #16]    ; 8460 <__do_global_dtors_aux+0x18> 844c: e5d32000 ldrb r2, [r3] 8450:    e3520000     cmp    r2, #0
    8454:    03a02001     moveq    r2, #1
    8458: 05c32000 strbeq r2, [r3] 845c: e12fff1e bx lr 8460:    00011538     .word    0x00011538

00008464 <frame_dummy>: 8464:    e59f0020     ldr    r0, [pc, #32]    ; 848c <frame_dummy+0x28>
    8468: e92d4008 push {r3, lr} 846c: e5903000 ldr r3, [r0] 8470:    e3530000     cmp    r3, #0
    8474: 08bd8008 popeq {r3, pc} 8478:    e59f3010     ldr    r3, [pc, #16]    ; 8490 <frame_dummy+0x2c> 847c: e3530000 cmp r3, #0
    8480: 08bd8008 popeq {r3, pc} 8484: e12fff33 blx r3 8488: e8bd8008 pop {r3, pc} 848c: 00011410     .word    0x00011410 ... 00008498 <ln>: 8498: e92d4830 push {r4, r5, fp, lr} 849c: e28db00c add fp, sp, #12 84a0: e24dd030 sub sp, sp, #48    ; 0x30 84a4: e14b03fc strd r0, [fp, #-60]    ; 0xffffffc4 84a8: e3a0300f mov r3, #15 84ac: e50b3020 str r3, [fp, #-32]    ; 0xffffffe0 84b0: e14b03dc ldrd r0, [fp, #-60]    ; 0xffffffc4 84b4: e3a02000 mov r2, #0 84b8: e3a035ff mov r3, #1069547520    ; 0x3fc00000 84bc: e2833603 add r3, r3, #3145728    ; 0x300000 84c0: eb0000fc bl 88b8 <__aeabi_dsub> 84c4: e1a02000 mov r2, r0 84c8: e1a03001 mov r3, r1 84cc: e1a04002 mov r4, r2 84d0: e1a05003 mov r5, r3 84d4: e14b03dc ldrd r0, [fp, #-60]    ; 0xffffffc4 84d8: e3a02000 mov r2, #0 84dc: e3a035ff mov r3, #1069547520    ; 0x3fc00000 84e0: e2833603 add r3, r3, #3145728    ; 0x300000 84e4: eb0000f4 bl 88bc <__adddf3> 84e8: e1a02000 mov r2, r0 84ec: e1a03001 mov r3, r1 84f0: e1a00004 mov r0, r4 84f4: e1a01005 mov r1, r5 84f8: eb000275 bl 8ed4 <__aeabi_ddiv> 84fc: e1a02000 mov r2, r0 8500: e1a03001 mov r3, r1 8504:    e14b22fc     strd    r2, [fp, #-44]    ; 0xffffffd4
    8508:    e14b02dc     ldrd    r0, [fp, #-44]    ; 0xffffffd4 850c: e14b22dc ldrd r2, [fp, #-44]    ; 0xffffffd4
    8510:    eb0001d4     bl    8c68 <__aeabi_dmul>
    8514: e1a02000 mov r2, r0 8518: e1a03001 mov r3, r1 851c: e14b23f4 strd r2, [fp, #-52]    ; 0xffffffcc
    8520:    e51b3020     ldr    r3, [fp, #-32]    ; 0xffffffe0
    8524:    e1a03083     lsl    r3, r3, #1
    8528:    e2833001     add    r3, r3, #1 852c: e50b3014 str r3, [fp, #-20]    ; 0xffffffec
    8530:    e51b0014     ldr    r0, [fp, #-20]    ; 0xffffffec
    8534:    eb000194     bl    8b8c <__aeabi_i2d>
    8538: e1a02000 mov r2, r0 853c: e1a03001 mov r3, r1 8540:    e3a00000     mov    r0, #0
    8544:    e3a015ff     mov    r1, #1069547520    ; 0x3fc00000
    8548:    e2811603     add    r1, r1, #3145728    ; 0x300000 854c: eb000260 bl 8ed4 <__aeabi_ddiv>
    8550: e1a02000 mov r2, r0 8554: e1a03001 mov r3, r1 8558:    e14b21fc     strd    r2, [fp, #-28]    ; 0xffffffe4 855c: e51b3020 ldr r3, [fp, #-32]    ; 0xffffffe0
    8560:    e50b3010     str    r3, [fp, #-16] 8564:    ea00001c     b    85dc <ln+0x144>
    8568:    e51b3014     ldr    r3, [fp, #-20]    ; 0xffffffec 856c: e2433002 sub r3, r3, #2
    8570:    e50b3014     str    r3, [fp, #-20]    ; 0xffffffec
    8574:    e51b0014     ldr    r0, [fp, #-20]    ; 0xffffffec
    8578:    eb000183     bl    8b8c <__aeabi_i2d> 857c: e1a02000 mov r2, r0 8580: e1a03001 mov r3, r1 8584:    e3a00000     mov    r0, #0
    8588:    e3a015ff     mov    r1, #1069547520    ; 0x3fc00000 858c: e2811603 add r1, r1, #3145728    ; 0x300000
    8590:    eb00024f     bl    8ed4 <__aeabi_ddiv>
    8594: e1a02000 mov r2, r0 8598: e1a03001 mov r3, r1 859c: e1a04002 mov r4, r2 85a0: e1a05003 mov r5, r3 85a4: e14b03d4 ldrd r0, [fp, #-52]    ; 0xffffffcc 85a8: e14b21dc ldrd r2, [fp, #-28]    ; 0xffffffe4 85ac: eb0001ad bl 8c68 <__aeabi_dmul> 85b0: e1a02000 mov r2, r0 85b4: e1a03001 mov r3, r1 85b8: e1a00004 mov r0, r4 85bc: e1a01005 mov r1, r5 85c0: eb0000bd bl 88bc <__adddf3> 85c4: e1a02000 mov r2, r0 85c8: e1a03001 mov r3, r1 85cc: e14b21fc strd r2, [fp, #-28]    ; 0xffffffe4 85d0: e51b3010 ldr r3, [fp, #-16] 85d4: e2433001 sub r3, r3, #1 85d8: e50b3010 str r3, [fp, #-16] 85dc: e51b3010 ldr r3, [fp, #-16] 85e0: e3530000 cmp r3, #0 85e4: caffffdf bgt 8568 <ln+0xd0> 85e8: e14b22dc ldrd r2, [fp, #-44]    ; 0xffffffd4 85ec: e1a00002 mov r0, r2 85f0: e1a01003 mov r1, r3 85f4: eb0000b0 bl 88bc <__adddf3> 85f8: e1a02000 mov r2, r0 85fc: e1a03001 mov r3, r1 8600: e1a00002 mov r0, r2 8604: e1a01003 mov r1, r3 8608:    e14b21dc     ldrd    r2, [fp, #-28]    ; 0xffffffe4 860c: eb000195 bl 8c68 <__aeabi_dmul>
    8610: e1a02000 mov r2, r0 8614: e1a03001 mov r3, r1 8618: e1a00002 mov r0, r2 861c: e1a01003 mov r1, r3 8620:    e24bd00c     sub    sp, fp, #12
    8624: e8bd8830 pop {r4, r5, fp, pc} 00008628 <main>: 8628: e92d4830 push {r4, r5, fp, lr} 862c: e28db00c add fp, sp, #12
    8630:    e24dd030     sub    sp, sp, #48    ; 0x30
    8634:    e3a03000     mov    r3, #0
    8638:    e50b302c     str    r3, [fp, #-44]    ; 0xffffffd4 863c: e3a03000 mov r3, #0
    8640:    e50b3028     str    r3, [fp, #-40]    ; 0xffffffd8
    8644:    e3a03000     mov    r3, #0
    8648:    e50b3034     str    r3, [fp, #-52]    ; 0xffffffcc 864c: e3a03000 mov r3, #0
    8650:    e50b3030     str    r3, [fp, #-48]    ; 0xffffffd0
    8654:    e3a00002     mov    r0, #2
    8658:    e24b302c     sub    r3, fp, #44    ; 0x2c 865c: e1a01003 mov r1, r3 8660:    ebffff59     bl    83cc <_init+0x44>
    8664:    e3a02000     mov    r2, #0
    8668:    e3a035ff     mov    r3, #1069547520    ; 0x3fc00000 866c: e2833603 add r3, r3, #3145728    ; 0x300000
    8670:    e14b21fc     strd    r2, [fp, #-28]    ; 0xffffffe4
    8674:    ea000046     b    8794 <main+0x16c>
    8678:    e14b01dc     ldrd    r0, [fp, #-28]    ; 0xffffffe4 867c: e28f3f7b add r3, pc, #492    ; 0x1ec
    8680: e1c320d0 ldrd r2, [r3] 8684:    eb000177     bl    8c68 <__aeabi_dmul>
    8688: e1a02000 mov r2, r0 868c: e1a03001 mov r3, r1 8690: e1a04002 mov r4, r2 8694: e1a05003 mov r5, r3 8698:    e28f1f76     add    r1, pc, #472    ; 0x1d8 869c: e1c100d0 ldrd r0, [r1] 86a0: e14b21dc ldrd r2, [fp, #-28]    ; 0xffffffe4 86a4: eb000083 bl 88b8 <__aeabi_dsub> 86a8: e1a02000 mov r2, r0 86ac: e1a03001 mov r3, r1 86b0: e1a00004 mov r0, r4 86b4: e1a01005 mov r1, r5 86b8: eb000205 bl 8ed4 <__aeabi_ddiv> 86bc: e1a02000 mov r2, r0 86c0: e1a03001 mov r3, r1 86c4: e14b22f4 strd r2, [fp, #-36]    ; 0xffffffdc 86c8: e14b02d4 ldrd r0, [fp, #-36]    ; 0xffffffdc 86cc: e28f3f6b add r3, pc, #428    ; 0x1ac 86d0: e1c320d0 ldrd r2, [r3] 86d4: eb0001fe bl 8ed4 <__aeabi_ddiv> 86d8: e1a02000 mov r2, r0 86dc: e1a03001 mov r3, r1 86e0: e1a00002 mov r0, r2 86e4: e1a01003 mov r1, r3 86e8: ebffff6a bl 8498 <ln> 86ec: e1a02000 mov r2, r0 86f0: e1a03001 mov r3, r1 86f4: e1a00002 mov r0, r2 86f8: e1a01003 mov r1, r3 86fc: e28f3f61 add r3, pc, #388    ; 0x184
    8700: e1c320d0 ldrd r2, [r3] 8704:    eb0001f2     bl    8ed4 <__aeabi_ddiv>
    8708: e1a02000 mov r2, r0 870c: e1a03001 mov r3, r1 8710: e1a00002 mov r0, r2 8714: e1a01003 mov r1, r3 8718:    e28f3e17     add    r3, pc, #368    ; 0x170 871c: e1c320d0 ldrd r2, [r3] 8720:    eb000065     bl    88bc <__adddf3>
    8724: e1a02000 mov r2, r0 8728: e1a03001 mov r3, r1 872c: e3a00000 mov r0, #0
    8730:    e3a015ff     mov    r1, #1069547520    ; 0x3fc00000
    8734:    e2811603     add    r1, r1, #3145728    ; 0x300000
    8738:    eb0001e5     bl    8ed4 <__aeabi_ddiv> 873c: e1a02000 mov r2, r0 8740: e1a03001 mov r3, r1 8744: e1a00002 mov r0, r2 8748: e1a01003 mov r1, r3 874c: e28f3f51 add r3, pc, #324    ; 0x144
    8750: e1c320d0 ldrd r2, [r3] 8754:    eb000057     bl    88b8 <__aeabi_dsub>
    8758: e1a02000 mov r2, r0 875c: e1a03001 mov r3, r1 8760: e1a00002 mov r0, r2 8764: e1a01003 mov r1, r3 8768:    eb0002a5     bl    9204 <__aeabi_d2iz> 876c: e1a03000 mov r3, r0 8770:    e50b3010     str    r3, [fp, #-16] 8774:    e14b01dc     ldrd    r0, [fp, #-28]    ; 0xffffffe4
    8778:    e3a02000     mov    r2, #0 877c: e3a035ff mov r3, #1069547520    ; 0x3fc00000
    8780:    e2833603     add    r3, r3, #3145728    ; 0x300000
    8784:    eb00004c     bl    88bc <__adddf3>
    8788: e1a02000 mov r2, r0 878c: e1a03001 mov r3, r1 8790:    e14b21fc     strd    r2, [fp, #-28]    ; 0xffffffe4
    8794:    e3a03001     mov    r3, #1
    8798: e1a04003 mov r4, r3 879c: e14b01dc ldrd r0, [fp, #-28]    ; 0xffffffe4 87a0: e28f30d0 add r3, pc, #208    ; 0xd0 87a4: e1c320d0 ldrd r2, [r3] 87a8: eb000281 bl 91b4 <__aeabi_dcmplt> 87ac: e1a03000 mov r3, r0 87b0: e3530000 cmp r3, #0 87b4: 1a000001 bne 87c0 <main+0x198> 87b8: e3a03000 mov r3, #0 87bc: e1a04003 mov r4, r3 87c0: e20430ff and r3, r4, #255    ; 0xff 87c4: e3530000 cmp r3, #0 87c8: 1affffaa bne 8678 <main+0x50> 87cc: e3a00002 mov r0, #2 87d0: e24b3034 sub r3, fp, #52    ; 0x34 87d4: e1a01003 mov r1, r3 87d8: ebfffefb bl 83cc <_init+0x44> 87dc: e59f10bc ldr r1, [pc, #188]    ; 88a0 <main+0x278> 87e0: e51b202c ldr r2, [fp, #-44]    ; 0xffffffd4 87e4: e51b3028 ldr r3, [fp, #-40]    ; 0xffffffd8 87e8: e1a00001 mov r0, r1 87ec: e1a01002 mov r1, r2 87f0: e1a02003 mov r2, r3 87f4: ebfffeeb bl 83a8 <_init+0x20> 87f8: e59f10a4 ldr r1, [pc, #164]    ; 88a4 <main+0x27c> 87fc: e51b2034 ldr r2, [fp, #-52]    ; 0xffffffcc
    8800:    e51b3030     ldr    r3, [fp, #-48]    ; 0xffffffd0
    8804: e1a00001 mov r0, r1 8808: e1a01002 mov r1, r2 880c: e1a02003 mov r2, r3 8810:    ebfffee4     bl    83a8 <_init+0x20>
    8814:    e59f008c     ldr    r0, [pc, #140]    ; 88a8 <main+0x280>
    8818:    e51b2034     ldr    r2, [fp, #-52]    ; 0xffffffcc 881c: e51b302c ldr r3, [fp, #-44]    ; 0xffffffd4
    8820: e0632002 rsb r2, r3, r2 8824:    e51b1030     ldr    r1, [fp, #-48]    ; 0xffffffd0
    8828:    e51b3028     ldr    r3, [fp, #-40]    ; 0xffffffd8 882c: e0633001 rsb r3, r3, r1 8830: e1a01000 mov r1, r0 8834: e1a00001 mov r0, r1 8838: e1a01002 mov r1, r2 883c: e1a02003 mov r2, r3 8840:    ebfffed8     bl    83a8 <_init+0x20>
    8844:    e59f2060     ldr    r2, [pc, #96]    ; 88ac <main+0x284>
    8848:    e51b3010     ldr    r3, [fp, #-16] 884c: e58d3000 str r3, [sp] 8850: e1a03002 mov r3, r2 8854: e1a00003 mov r0, r3 8858:    e14b21dc     ldrd    r2, [fp, #-28]    ; 0xffffffe4 885c: ebfffed1 bl 83a8 <_init+0x20>
    8860:    e3a03000     mov    r3, #0
    8864: e1a00003 mov r0, r3 8868:    e24bd00c     sub    sp, fp, #12 886c: e8bd8830 pop {r4, r5, fp, pc} 8870:    00000000     .word    0x00000000
    8874:    40e6f300     .word    0x40e6f300
    8878:    00000000     .word    0x00000000 887c: 409c2000 .word 0x409c2000
    8880:    00000000     .word    0x00000000
    8884:    40c38800     .word    0x40c38800
    8888:    00000000     .word    0x00000000 888c: 40aedc00 .word 0x40aedc00
    8890:    dcb5db83     .word    0xdcb5db83
    8894:    3f6b79e1     .word    0x3f6b79e1
    8898:    66666666     .word    0x66666666 889c: 40711266     .word    0x40711266 88a0: 00009338     .word    0x00009338 88a4: 00009354     .word    0x00009354 88a8: 00009370     .word    0x00009370 88ac: 00009388     .word    0x00009388 000088b0 <__aeabi_drsub>: 88b0: e2211102 eor r1, r1, #-2147483648    ; 0x80000000 88b4: ea000000 b 88bc <__adddf3> 000088b8 <__aeabi_dsub>: 88b8: e2233102 eor r3, r3, #-2147483648    ; 0x80000000 000088bc <__adddf3>: 88bc: e92d4030 push {r4, r5, lr} 88c0: e1a04081 lsl r4, r1, #1 88c4: e1a05083 lsl r5, r3, #1 88c8: e1340005 teq r4, r5 88cc: 01300002 teqeq r0, r2 88d0: 1194c000 orrsne ip, r4, r0 88d4: 1195c002 orrsne ip, r5, r2 88d8: 11f0cac4 mvnsne ip, r4, asr #21 88dc: 11f0cac5 mvnsne ip, r5, asr #21 88e0: 0a000079 beq 8acc <__adddf3+0x210> 88e4: e1a04aa4 lsr r4, r4, #21 88e8: e0745aa5 rsbs r5, r4, r5, lsr #21 88ec: b2655000 rsblt r5, r5, #0 88f0: da000006 ble 8910 <__adddf3+0x54> 88f4: e0844005 add r4, r4, r5 88f8: e0202002 eor r2, r0, r2 88fc: e0213003 eor r3, r1, r3 8900: e0220000 eor r0, r2, r0 8904: e0231001 eor r1, r3, r1 8908: e0202002 eor r2, r0, r2 890c: e0213003 eor r3, r1, r3 8910:    e3550036     cmp    r5, #54    ; 0x36
    8914: 88bd8030 pophi {r4, r5, pc} 8918:    e3110102     tst    r1, #-2147483648    ; 0x80000000 891c: e1a01601 lsl r1, r1, #12
    8920:    e3a0c601     mov    ip, #1048576    ; 0x100000
    8924:    e18c1621     orr    r1, ip, r1, lsr #12
    8928:    0a000001     beq    8934 <__adddf3+0x78> 892c: e2700000 rsbs r0, r0, #0
    8930:    e2e11000     rsc    r1, r1, #0
    8934:    e3130102     tst    r3, #-2147483648    ; 0x80000000
    8938:    e1a03603     lsl    r3, r3, #12 893c: e18c3623 orr r3, ip, r3, lsr #12
    8940:    0a000001     beq    894c <__adddf3+0x90>
    8944:    e2722000     rsbs    r2, r2, #0
    8948:    e2e33000     rsc    r3, r3, #0 894c: e1340005 teq r4, r5 8950:    0a000057     beq    8ab4 <__adddf3+0x1f8>
    8954:    e2444001     sub    r4, r4, #1
    8958:    e275e020     rsbs    lr, r5, #32 895c: ba000005 blt 8978 <__adddf3+0xbc>
    8960: e1a0ce12 lsl ip, r2, lr 8964: e0900532 adds r0, r0, r2, lsr r5 8968:    e2a11000     adc    r1, r1, #0 896c: e0900e13 adds r0, r0, r3, lsl lr 8970: e0b11553 adcs r1, r1, r3, asr r5 8974:    ea000006     b    8994 <__adddf3+0xd8>
    8978:    e2455020     sub    r5, r5, #32 897c: e28ee020 add lr, lr, #32
    8980:    e3520001     cmp    r2, #1
    8984: e1a0ce13 lsl ip, r3, lr 8988:    238cc002     orrcs    ip, ip, #2 898c: e0900553 adds r0, r0, r3, asr r5 8990:    e0b11fc3     adcs    r1, r1, r3, asr #31
    8994:    e2015102     and    r5, r1, #-2147483648    ; 0x80000000
    8998:    5a000002     bpl    89a8 <__adddf3+0xec> 899c: e27cc000 rsbs ip, ip, #0 89a0: e2f00000 rscs r0, r0, #0 89a4: e2e11000 rsc r1, r1, #0 89a8: e3510601 cmp r1, #1048576    ; 0x100000 89ac: 3a00000e bcc 89ec <__adddf3+0x130> 89b0: e3510602 cmp r1, #2097152    ; 0x200000 89b4: 3a000006 bcc 89d4 <__adddf3+0x118> 89b8: e1b010a1 lsrs r1, r1, #1 89bc: e1b00060 rrxs r0, r0 89c0: e1a0c06c rrx ip, ip 89c4: e2844001 add r4, r4, #1 89c8: e1a02a84 lsl r2, r4, #21 89cc: e3720501 cmn r2, #4194304    ; 0x400000 89d0: 2a000055 bcs 8b2c <__adddf3+0x270> 89d4: e35c0102 cmp ip, #-2147483648    ; 0x80000000 89d8: 01b0c0a0 lsrseq ip, r0, #1 89dc: e2b00000 adcs r0, r0, #0 89e0: e0a11a04 adc r1, r1, r4, lsl #20 89e4: e1811005 orr r1, r1, r5 89e8: e8bd8030 pop {r4, r5, pc} 89ec: e1b0c08c lsls ip, ip, #1 89f0: e0b00000 adcs r0, r0, r0 89f4: e0a11001 adc r1, r1, r1 89f8: e3110601 tst r1, #1048576    ; 0x100000 89fc: e2444001 sub r4, r4, #1 8a00: 1afffff3 bne 89d4 <__adddf3+0x118> 8a04: e3310000 teq r1, #0 8a08: 01a01000 moveq r1, r0 8a0c: 03a00000 moveq r0, #0 8a10: e16f3f11 clz r3, r1 8a14: 02833020     addeq    r3, r3, #32 8a18: e243300b sub r3, r3, #11 8a1c: e2532020 subs r2, r3, #32 8a20: aa000007 bge 8a44 <__adddf3+0x188> 8a24: e292200c adds r2, r2, #12 8a28: da000004 ble 8a40 <__adddf3+0x184> 8a2c: e282c014 add ip, r2, #20 8a30: e262200c rsb r2, r2, #12 8a34: e1a00c11 lsl r0, r1, ip 8a38: e1a01231 lsr r1, r1, r2 8a3c: ea000004 b 8a54 <__adddf3+0x198> 8a40: e2822014 add r2, r2, #20 8a44: d262c020 rsble ip, r2, #32 8a48: e1a01211 lsl r1, r1, r2 8a4c: d1811c30 orrle r1, r1, r0, lsr ip 8a50: d1a00210 lslle r0, r0, r2 8a54: e0544003 subs r4, r4, r3 8a58: a0811a04 addge r1, r1, r4, lsl #20 8a5c: a1811005 orrge r1, r1, r5 8a60: a8bd8030 popge {r4, r5, pc} 8a64: e1e04004 mvn r4, r4 8a68: e254401f subs r4, r4, #31 8a6c: aa00000d bge 8aa8 <__adddf3+0x1ec> 8a70: e294400c adds r4, r4, #12 8a74: ca000005 bgt 8a90 <__adddf3+0x1d4> 8a78: e2844014 add r4, r4, #20 8a7c: e2642020 rsb r2, r4, #32 8a80: e1a00430 lsr r0, r0, r4 8a84: e1800211 orr r0, r0, r1, lsl r2 8a88: e1851431 orr r1, r5, r1, lsr r4 8a8c: e8bd8030 pop {r4, r5, pc} 8a90: e264400c rsb r4, r4, #12 8a94: e2642020 rsb r2, r4, #32 8a98: e1a00230 lsr r0, r0, r2 8a9c: e1800411 orr r0, r0, r1, lsl r4 8aa0: e1a01005 mov r1, r5 8aa4: e8bd8030 pop {r4, r5, pc} 8aa8: e1a00431 lsr r0, r1, r4 8aac: e1a01005 mov r1, r5 8ab0: e8bd8030 pop {r4, r5, pc} 8ab4: e3340000 teq r4, #0 8ab8: e2233601 eor r3, r3, #1048576    ; 0x100000 8abc: 02211601     eoreq    r1, r1, #1048576    ; 0x100000 8ac0: 02844001     addeq    r4, r4, #1 8ac4: 12455001     subne    r5, r5, #1 8ac8: eaffffa1 b 8954 <__adddf3+0x98> 8acc: e1f0cac4 mvns ip, r4, asr #21 8ad0: 11f0cac5 mvnsne ip, r5, asr #21 8ad4: 0a000018 beq 8b3c <__adddf3+0x280> 8ad8: e1340005 teq r4, r5 8adc: 01300002 teqeq r0, r2 8ae0: 0a000003 beq 8af4 <__adddf3+0x238> 8ae4: e194c000 orrs ip, r4, r0 8ae8: 01a01003 moveq r1, r3 8aec: 01a00002 moveq r0, r2 8af0: e8bd8030 pop {r4, r5, pc} 8af4: e1310003 teq r1, r3 8af8: 13a01000 movne r1, #0 8afc: 13a00000 movne r0, #0 8b00: 18bd8030 popne {r4, r5, pc} 8b04: e1b0caa4 lsrs ip, r4, #21 8b08: 1a000003 bne 8b1c <__adddf3+0x260> 8b0c: e1b00080 lsls r0, r0, #1 8b10: e0b11001 adcs r1, r1, r1 8b14: 23811102     orrcs    r1, r1, #-2147483648    ; 0x80000000 8b18: e8bd8030 pop {r4, r5, pc} 8b1c: e2944501 adds r4, r4, #4194304    ; 0x400000 8b20: 32811601     addcc    r1, r1, #1048576    ; 0x100000 8b24: 38bd8030 popcc {r4, r5, pc} 8b28: e2015102 and r5, r1, #-2147483648    ; 0x80000000 8b2c: e385147f orr r1, r5, #2130706432    ; 0x7f000000 8b30: e381160f orr r1, r1, #15728640    ; 0xf00000 8b34: e3a00000 mov r0, #0 8b38: e8bd8030 pop {r4, r5, pc} 8b3c: e1f0cac4 mvns ip, r4, asr #21 8b40: 11a01003 movne r1, r3 8b44: 11a00002 movne r0, r2 8b48: 01f0cac5 mvnseq ip, r5, asr #21 8b4c: 11a03001 movne r3, r1 8b50: 11a02000 movne r2, r0 8b54: e1904601 orrs r4, r0, r1, lsl #12 8b58: 01925603     orrseq    r5, r2, r3, lsl #12 8b5c: 01310003 teqeq r1, r3 8b60: 13811702     orrne    r1, r1, #524288    ; 0x80000 8b64: e8bd8030 pop {r4, r5, pc} 00008b68 <__aeabi_ui2d>: 8b68: e3300000 teq r0, #0 8b6c: 03a01000 moveq r1, #0 8b70: 012fff1e bxeq lr 8b74: e92d4030 push {r4, r5, lr} 8b78: e3a04b01 mov r4, #1024    ; 0x400 8b7c: e2844032 add r4, r4, #50    ; 0x32 8b80: e3a05000 mov r5, #0 8b84: e3a01000 mov r1, #0 8b88: eaffff9d b 8a04 <__adddf3+0x148> 00008b8c <__aeabi_i2d>: 8b8c: e3300000 teq r0, #0 8b90: 03a01000 moveq r1, #0 8b94: 012fff1e bxeq lr 8b98: e92d4030 push {r4, r5, lr} 8b9c: e3a04b01 mov r4, #1024    ; 0x400 8ba0: e2844032 add r4, r4, #50    ; 0x32 8ba4: e2105102 ands r5, r0, #-2147483648    ; 0x80000000 8ba8: 42600000     rsbmi    r0, r0, #0 8bac: e3a01000 mov r1, #0 8bb0: eaffff93 b 8a04 <__adddf3+0x148> 00008bb4 <__aeabi_f2d>: 8bb4: e1b02080 lsls r2, r0, #1 8bb8: e1a011c2 asr r1, r2, #3 8bbc: e1a01061 rrx r1, r1 8bc0: e1a00e02 lsl r0, r2, #28 8bc4: 121234ff andsne r3, r2, #-16777216    ; 0xff000000 8bc8: 133304ff teqne r3, #-16777216    ; 0xff000000 8bcc: 1221130e eorne r1, r1, #939524096    ; 0x38000000 8bd0: 112fff1e bxne lr 8bd4: e3320000 teq r2, #0 8bd8: 133304ff teqne r3, #-16777216    ; 0xff000000 8bdc: 012fff1e bxeq lr 8be0: e92d4030 push {r4, r5, lr} 8be4: e3a04d0e mov r4, #896    ; 0x380 8be8: e2015102 and r5, r1, #-2147483648    ; 0x80000000 8bec: e3c11102 bic r1, r1, #-2147483648    ; 0x80000000 8bf0: eaffff83 b 8a04 <__adddf3+0x148> 00008bf4 <__aeabi_ul2d>: 8bf4: e1902001 orrs r2, r0, r1 8bf8: 012fff1e bxeq lr 8bfc: e92d4030 push {r4, r5, lr} 8c00: e3a05000 mov r5, #0 8c04: ea000006 b 8c24 <__aeabi_l2d+0x1c> 00008c08 <__aeabi_l2d>: 8c08: e1902001 orrs r2, r0, r1 8c0c: 012fff1e bxeq lr 8c10: e92d4030 push {r4, r5, lr} 8c14: e2115102 ands r5, r1, #-2147483648    ; 0x80000000 8c18: 5a000001 bpl 8c24 <__aeabi_l2d+0x1c> 8c1c: e2700000 rsbs r0, r0, #0 8c20: e2e11000 rsc r1, r1, #0 8c24: e3a04b01 mov r4, #1024    ; 0x400 8c28: e2844032 add r4, r4, #50    ; 0x32 8c2c: e1b0cb21 lsrs ip, r1, #22 8c30: 0affff5c beq 89a8 <__adddf3+0xec> 8c34: e3a02003 mov r2, #3 8c38: e1b0c1ac lsrs ip, ip, #3 8c3c: 12822003     addne    r2, r2, #3 8c40: e1b0c1ac lsrs ip, ip, #3 8c44: 12822003     addne    r2, r2, #3 8c48: e08221ac add r2, r2, ip, lsr #3 8c4c: e2623020 rsb r3, r2, #32 8c50: e1a0c310 lsl ip, r0, r3 8c54: e1a00230 lsr r0, r0, r2 8c58: e1800311 orr r0, r0, r1, lsl r3 8c5c: e1a01231 lsr r1, r1, r2 8c60: e0844002 add r4, r4, r2 8c64: eaffff4f b 89a8 <__adddf3+0xec> 00008c68 <__aeabi_dmul>: 8c68: e92d4070 push {r4, r5, r6, lr} 8c6c: e3a0c0ff mov ip, #255    ; 0xff 8c70: e38ccc07 orr ip, ip, #1792    ; 0x700 8c74: e01c4a21 ands r4, ip, r1, lsr #20 8c78: 101c5a23 andsne r5, ip, r3, lsr #20 8c7c: 1134000c teqne r4, ip 8c80: 1135000c teqne r5, ip 8c84: 0b00006f bleq 8e48 <__aeabi_dmul+0x1e0> 8c88: e0844005 add r4, r4, r5 8c8c: e0216003 eor r6, r1, r3 8c90: e1c11a8c bic r1, r1, ip, lsl #21 8c94: e1c33a8c bic r3, r3, ip, lsl #21 8c98: e1905601 orrs r5, r0, r1, lsl #12 8c9c: 11925603     orrsne    r5, r2, r3, lsl #12 8ca0: e3811601 orr r1, r1, #1048576    ; 0x100000 8ca4: e3833601 orr r3, r3, #1048576    ; 0x100000 8ca8: 0a00001c beq 8d20 <__aeabi_dmul+0xb8> 8cac: e08ec290 umull ip, lr, r0, r2 8cb0: e3a05000 mov r5, #0 8cb4: e0a5e291 umlal lr, r5, r1, r2 8cb8: e2062102 and r2, r6, #-2147483648    ; 0x80000000 8cbc: e0a5e390 umlal lr, r5, r0, r3 8cc0: e3a06000 mov r6, #0 8cc4: e0a65391 umlal r5, r6, r1, r3 8cc8: e33c0000 teq ip, #0 8ccc: 138ee001 orrne lr, lr, #1 8cd0: e24440ff sub r4, r4, #255    ; 0xff 8cd4: e3560c02 cmp r6, #512    ; 0x200 8cd8: e2c44c03 sbc r4, r4, #768    ; 0x300 8cdc: 2a000002 bcs 8cec <__aeabi_dmul+0x84> 8ce0: e1b0e08e lsls lr, lr, #1 8ce4: e0b55005 adcs r5, r5, r5 8ce8: e0a66006 adc r6, r6, r6 8cec: e1821586 orr r1, r2, r6, lsl #11 8cf0: e1811aa5 orr r1, r1, r5, lsr #21 8cf4: e1a00585 lsl r0, r5, #11 8cf8: e1800aae orr r0, r0, lr, lsr #21 8cfc: e1a0e58e lsl lr, lr, #11 8d00: e254c0fd subs ip, r4, #253    ; 0xfd 8d04: 835c0c07 cmphi ip, #1792    ; 0x700 8d08: 8a00000f bhi 8d4c <__aeabi_dmul+0xe4> 8d0c: e35e0102 cmp lr, #-2147483648    ; 0x80000000 8d10: 01b0e0a0 lsrseq lr, r0, #1 8d14: e2b00000 adcs r0, r0, #0 8d18: e0a11a04 adc r1, r1, r4, lsl #20 8d1c: e8bd8070 pop {r4, r5, r6, pc} 8d20: e2066102 and r6, r6, #-2147483648    ; 0x80000000 8d24: e1861001 orr r1, r6, r1 8d28: e1800002 orr r0, r0, r2 8d2c: e0211003 eor r1, r1, r3 8d30: e05440ac subs r4, r4, ip, lsr #1 8d34: c074500c rsbsgt r5, r4, ip 8d38: c1811a04 orrgt r1, r1, r4, lsl #20 8d3c: c8bd8070 popgt {r4, r5, r6, pc} 8d40: e3811601 orr r1, r1, #1048576    ; 0x100000 8d44: e3a0e000 mov lr, #0 8d48: e2544001 subs r4, r4, #1 8d4c: ca000058 bgt 8eb4 <__aeabi_dmul+0x24c> 8d50: e3740036 cmn r4, #54    ; 0x36 8d54: d3a00000 movle r0, #0 8d58: d2011102 andle r1, r1, #-2147483648    ; 0x80000000 8d5c: d8bd8070 pople {r4, r5, r6, pc} 8d60: e2644000 rsb r4, r4, #0 8d64: e2544020 subs r4, r4, #32 8d68: aa000018 bge 8dd0 <__aeabi_dmul+0x168> 8d6c: e294400c adds r4, r4, #12 8d70: ca00000b bgt 8da4 <__aeabi_dmul+0x13c> 8d74: e2844014 add r4, r4, #20 8d78: e2645020 rsb r5, r4, #32 8d7c: e1a03510 lsl r3, r0, r5 8d80: e1a00430 lsr r0, r0, r4 8d84: e1800511 orr r0, r0, r1, lsl r5 8d88: e2012102 and r2, r1, #-2147483648    ; 0x80000000 8d8c: e3c11102 bic r1, r1, #-2147483648    ; 0x80000000 8d90: e0900fa3 adds r0, r0, r3, lsr #31 8d94: e0a21431 adc r1, r2, r1, lsr r4 8d98: e19ee083 orrs lr, lr, r3, lsl #1 8d9c: 01c00fa3 biceq r0, r0, r3, lsr #31 8da0: e8bd8070 pop {r4, r5, r6, pc} 8da4: e264400c rsb r4, r4, #12 8da8: e2645020 rsb r5, r4, #32 8dac: e1a03410 lsl r3, r0, r4 8db0: e1a00530 lsr r0, r0, r5 8db4: e1800411 orr r0, r0, r1, lsl r4 8db8: e2011102 and r1, r1, #-2147483648    ; 0x80000000 8dbc: e0900fa3 adds r0, r0, r3, lsr #31 8dc0: e2a11000 adc r1, r1, #0 8dc4: e19ee083 orrs lr, lr, r3, lsl #1 8dc8: 01c00fa3 biceq r0, r0, r3, lsr #31 8dcc: e8bd8070 pop {r4, r5, r6, pc} 8dd0: e2645020 rsb r5, r4, #32 8dd4: e18ee510 orr lr, lr, r0, lsl r5 8dd8: e1a03430 lsr r3, r0, r4 8ddc: e1833511 orr r3, r3, r1, lsl r5 8de0: e1a00431 lsr r0, r1, r4 8de4: e2011102 and r1, r1, #-2147483648    ; 0x80000000 8de8: e1c00431 bic r0, r0, r1, lsr r4 8dec: e0800fa3 add r0, r0, r3, lsr #31 8df0: e19ee083 orrs lr, lr, r3, lsl #1 8df4: 01c00fa3 biceq r0, r0, r3, lsr #31 8df8: e8bd8070 pop {r4, r5, r6, pc} 8dfc: e3340000 teq r4, #0 8e00: 1a000008 bne 8e28 <__aeabi_dmul+0x1c0> 8e04: e2016102 and r6, r1, #-2147483648    ; 0x80000000 8e08: e1b00080 lsls r0, r0, #1 8e0c: e0a11001 adc r1, r1, r1 8e10: e3110601 tst r1, #1048576    ; 0x100000 8e14: 02444001     subeq    r4, r4, #1 8e18: 0afffffa beq 8e08 <__aeabi_dmul+0x1a0> 8e1c: e1811006 orr r1, r1, r6 8e20: e3350000 teq r5, #0 8e24: 112fff1e bxne lr 8e28: e2036102 and r6, r3, #-2147483648    ; 0x80000000 8e2c: e1b02082 lsls r2, r2, #1 8e30: e0a33003 adc r3, r3, r3 8e34: e3130601 tst r3, #1048576    ; 0x100000 8e38: 02455001     subeq    r5, r5, #1 8e3c: 0afffffa beq 8e2c <__aeabi_dmul+0x1c4> 8e40: e1833006 orr r3, r3, r6 8e44: e12fff1e bx lr 8e48: e134000c teq r4, ip 8e4c: e00c5a23 and r5, ip, r3, lsr #20 8e50: 1135000c teqne r5, ip 8e54: 0a000006 beq 8e74 <__aeabi_dmul+0x20c> 8e58: e1906081 orrs r6, r0, r1, lsl #1 8e5c: 11926083     orrsne    r6, r2, r3, lsl #1 8e60: 1affffe5 bne 8dfc <__aeabi_dmul+0x194> 8e64: e0211003 eor r1, r1, r3 8e68: e2011102 and r1, r1, #-2147483648    ; 0x80000000 8e6c: e3a00000 mov r0, #0 8e70: e8bd8070 pop {r4, r5, r6, pc} 8e74: e1906081 orrs r6, r0, r1, lsl #1 8e78: 01a00002 moveq r0, r2 8e7c: 01a01003 moveq r1, r3 8e80: 11926083     orrsne    r6, r2, r3, lsl #1 8e84: 0a00000f beq 8ec8 <__aeabi_dmul+0x260> 8e88: e134000c teq r4, ip 8e8c: 1a000001 bne 8e98 <__aeabi_dmul+0x230> 8e90: e1906601 orrs r6, r0, r1, lsl #12 8e94: 1a00000b bne 8ec8 <__aeabi_dmul+0x260> 8e98: e135000c teq r5, ip 8e9c: 1a000003 bne 8eb0 <__aeabi_dmul+0x248> 8ea0: e1926603 orrs r6, r2, r3, lsl #12 8ea4: 11a00002 movne r0, r2 8ea8: 11a01003 movne r1, r3 8eac: 1a000005 bne 8ec8 <__aeabi_dmul+0x260> 8eb0: e0211003 eor r1, r1, r3 8eb4: e2011102 and r1, r1, #-2147483648    ; 0x80000000 8eb8: e381147f orr r1, r1, #2130706432    ; 0x7f000000 8ebc: e381160f orr r1, r1, #15728640    ; 0xf00000 8ec0: e3a00000 mov r0, #0 8ec4: e8bd8070 pop {r4, r5, r6, pc} 8ec8: e381147f orr r1, r1, #2130706432    ; 0x7f000000 8ecc: e381173e orr r1, r1, #16252928    ; 0xf80000 8ed0: e8bd8070 pop {r4, r5, r6, pc} 00008ed4 <__aeabi_ddiv>: 8ed4: e92d4070 push {r4, r5, r6, lr} 8ed8: e3a0c0ff mov ip, #255    ; 0xff 8edc: e38ccc07 orr ip, ip, #1792    ; 0x700 8ee0: e01c4a21 ands r4, ip, r1, lsr #20 8ee4: 101c5a23 andsne r5, ip, r3, lsr #20 8ee8: 1134000c teqne r4, ip 8eec: 1135000c teqne r5, ip 8ef0: 0b00005c bleq 9068 <__aeabi_ddiv+0x194> 8ef4: e0444005 sub r4, r4, r5 8ef8: e021e003 eor lr, r1, r3 8efc: e1925603 orrs r5, r2, r3, lsl #12 8f00: e1a01601 lsl r1, r1, #12 8f04: 0a00004b beq 9038 <__aeabi_ddiv+0x164> 8f08: e1a03603 lsl r3, r3, #12 8f0c: e3a05201 mov r5, #268435456    ; 0x10000000 8f10: e1853223 orr r3, r5, r3, lsr #4 8f14: e1833c22 orr r3, r3, r2, lsr #24 8f18: e1a02402 lsl r2, r2, #8 8f1c: e1855221 orr r5, r5, r1, lsr #4 8f20: e1855c20 orr r5, r5, r0, lsr #24 8f24: e1a06400 lsl r6, r0, #8 8f28: e20e1102 and r1, lr, #-2147483648    ; 0x80000000 8f2c: e1550003 cmp r5, r3 8f30: 01560002 cmpeq r6, r2 8f34: e2a440fd adc r4, r4, #253    ; 0xfd 8f38: e2844c03 add r4, r4, #768    ; 0x300 8f3c: 2a000001 bcs 8f48 <__aeabi_ddiv+0x74> 8f40: e1b030a3 lsrs r3, r3, #1 8f44: e1a02062 rrx r2, r2 8f48: e0566002 subs r6, r6, r2 8f4c: e0c55003 sbc r5, r5, r3 8f50: e1b030a3 lsrs r3, r3, #1 8f54: e1a02062 rrx r2, r2 8f58: e3a00601 mov r0, #1048576    ; 0x100000 8f5c: e3a0c702 mov ip, #524288    ; 0x80000 8f60: e056e002 subs lr, r6, r2 8f64: e0d5e003 sbcs lr, r5, r3 8f68: 20466002 subcs r6, r6, r2 8f6c: 21a0500e movcs r5, lr 8f70: 2180000c orrcs r0, r0, ip 8f74: e1b030a3 lsrs r3, r3, #1 8f78: e1a02062 rrx r2, r2 8f7c: e056e002 subs lr, r6, r2 8f80: e0d5e003 sbcs lr, r5, r3 8f84: 20466002 subcs r6, r6, r2 8f88: 21a0500e movcs r5, lr 8f8c: 218000ac orrcs r0, r0, ip, lsr #1 8f90: e1b030a3 lsrs r3, r3, #1 8f94: e1a02062 rrx r2, r2 8f98: e056e002 subs lr, r6, r2 8f9c: e0d5e003 sbcs lr, r5, r3 8fa0: 20466002 subcs r6, r6, r2 8fa4: 21a0500e movcs r5, lr 8fa8: 2180012c orrcs r0, r0, ip, lsr #2 8fac: e1b030a3 lsrs r3, r3, #1 8fb0: e1a02062 rrx r2, r2 8fb4: e056e002 subs lr, r6, r2 8fb8: e0d5e003 sbcs lr, r5, r3 8fbc: 20466002 subcs r6, r6, r2 8fc0: 21a0500e movcs r5, lr 8fc4: 218001ac orrcs r0, r0, ip, lsr #3 8fc8: e195e006 orrs lr, r5, r6 8fcc: 0a00000d beq 9008 <__aeabi_ddiv+0x134> 8fd0: e1a05205 lsl r5, r5, #4 8fd4: e1855e26 orr r5, r5, r6, lsr #28 8fd8: e1a06206 lsl r6, r6, #4 8fdc: e1a03183 lsl r3, r3, #3 8fe0: e1833ea2 orr r3, r3, r2, lsr #29 8fe4: e1a02182 lsl r2, r2, #3 8fe8: e1b0c22c lsrs ip, ip, #4 8fec: 1affffdb bne 8f60 <__aeabi_ddiv+0x8c> 8ff0: e3110601 tst r1, #1048576    ; 0x100000 8ff4: 1a000006 bne 9014 <__aeabi_ddiv+0x140> 8ff8: e1811000 orr r1, r1, r0 8ffc: e3a00000 mov r0, #0
    9000:    e3a0c102     mov    ip, #-2147483648    ; 0x80000000
    9004:    eaffffd5     b    8f60 <__aeabi_ddiv+0x8c>
    9008:    e3110601     tst    r1, #1048576    ; 0x100000 900c: 01811000 orreq r1, r1, r0 9010:    03a00000     moveq    r0, #0
    9014:    e254c0fd     subs    ip, r4, #253    ; 0xfd
    9018:    835c0c07     cmphi    ip, #1792    ; 0x700 901c: 8affff4a bhi 8d4c <__aeabi_dmul+0xe4>
    9020: e055c003 subs ip, r5, r3 9024: 0056c002 subseq ip, r6, r2 9028:    01b0c0a0     lsrseq    ip, r0, #1 902c: e2b00000 adcs r0, r0, #0
    9030:    e0a11a04     adc    r1, r1, r4, lsl #20
    9034: e8bd8070 pop {r4, r5, r6, pc} 9038:    e20ee102     and    lr, lr, #-2147483648    ; 0x80000000 903c: e18e1621 orr r1, lr, r1, lsr #12
    9040:    e09440ac     adds    r4, r4, ip, lsr #1
    9044: c074500c rsbsgt r5, r4, ip 9048:    c1811a04     orrgt    r1, r1, r4, lsl #20 904c: c8bd8070 popgt {r4, r5, r6, pc} 9050:    e3811601     orr    r1, r1, #1048576    ; 0x100000
    9054:    e3a0e000     mov    lr, #0
    9058:    e2544001     subs    r4, r4, #1 905c: eaffff3a b 8d4c <__aeabi_dmul+0xe4>
    9060: e185e006 orr lr, r5, r6 9064:    eaffff38     b    8d4c <__aeabi_dmul+0xe4>
    9068:    e00c5a23     and    r5, ip, r3, lsr #20 906c: e134000c teq r4, ip 9070: 0135000c teqeq r5, ip 9074:    0affff93     beq    8ec8 <__aeabi_dmul+0x260>
    9078: e134000c teq r4, ip 907c: 1a000006 bne 909c <__aeabi_ddiv+0x1c8>
    9080:    e1904601     orrs    r4, r0, r1, lsl #12
    9084:    1affff8f     bne    8ec8 <__aeabi_dmul+0x260>
    9088: e135000c teq r5, ip 908c: 1affff87 bne 8eb0 <__aeabi_dmul+0x248>
    9090: e1a00002 mov r0, r2 9094: e1a01003 mov r1, r3 9098:    eaffff8a     b    8ec8 <__aeabi_dmul+0x260> 909c: e135000c teq r5, ip 90a0: 1a000004 bne 90b8 <__aeabi_ddiv+0x1e4> 90a4: e1925603 orrs r5, r2, r3, lsl #12 90a8: 0affff6d beq 8e64 <__aeabi_dmul+0x1fc> 90ac: e1a00002 mov r0, r2 90b0: e1a01003 mov r1, r3 90b4: eaffff83 b 8ec8 <__aeabi_dmul+0x260> 90b8: e1906081 orrs r6, r0, r1, lsl #1 90bc: 11926083     orrsne    r6, r2, r3, lsl #1 90c0: 1affff4d bne 8dfc <__aeabi_dmul+0x194> 90c4: e1904081 orrs r4, r0, r1, lsl #1 90c8: 1affff78 bne 8eb0 <__aeabi_dmul+0x248> 90cc: e1925083 orrs r5, r2, r3, lsl #1 90d0: 1affff63 bne 8e64 <__aeabi_dmul+0x1fc> 90d4: eaffff7b b 8ec8 <__aeabi_dmul+0x260> 000090d8 <__gedf2>: 90d8: e3e0c000 mvn ip, #0 90dc: ea000002 b 90ec <__cmpdf2+0x4> 000090e0 <__ledf2>: 90e0: e3a0c001 mov ip, #1 90e4: ea000000 b 90ec <__cmpdf2+0x4> 000090e8 <__cmpdf2>: 90e8: e3a0c001 mov ip, #1 90ec: e52dc004 push {ip} ; (str ip, [sp, #-4]!) 90f0: e1a0c081 lsl ip, r1, #1 90f4: e1f0cacc mvns ip, ip, asr #21 90f8: e1a0c083 lsl ip, r3, #1 90fc: 11f0cacc mvnsne ip, ip, asr #21
    9100:    0a00000e     beq    9140 <__cmpdf2+0x58>
    9104:    e28dd004     add    sp, sp, #4
    9108:    e190c081     orrs    ip, r0, r1, lsl #1 910c: 0192c083 orrseq ip, r2, r3, lsl #1
    9110:    11310003 teqne r1, r3 9114:    01300002 teqeq r0, r2 9118:    03a00000     moveq    r0, #0 911c: 012fff1e bxeq lr 9120:    e3700000     cmn    r0, #0
    9124: e1310003 teq r1, r3 9128:    51510003 cmppl r1, r3 912c: 01500002 cmpeq r0, r2 9130:    21a00fc3     asrcs    r0, r3, #31
    9134:    31e00fc3     mvncc    r0, r3, asr #31
    9138:    e3800001     orr    r0, r0, #1 913c: e12fff1e bx lr 9140:    e1a0c081     lsl    ip, r1, #1
    9144:    e1f0cacc     mvns    ip, ip, asr #21
    9148:    1a000001     bne    9154 <__cmpdf2+0x6c> 914c: e190c601 orrs ip, r0, r1, lsl #12
    9150:    1a000004     bne    9168 <__cmpdf2+0x80>
    9154:    e1a0c083     lsl    ip, r3, #1
    9158:    e1f0cacc     mvns    ip, ip, asr #21 915c: 1affffe8 bne 9104 <__cmpdf2+0x1c>
    9160:    e192c603     orrs    ip, r2, r3, lsl #12
    9164:    0affffe6     beq    9104 <__cmpdf2+0x1c>
    9168:    e49d0004     pop    {r0}        ; (ldr r0, [sp], #4) 916c: e12fff1e bx lr 00009170 <__aeabi_cdrcmple>: 9170: e1a0c000 mov ip, r0 9174: e1a00002 mov r0, r2 9178: e1a0200c mov r2, ip 917c: e1a0c001 mov ip, r1 9180: e1a01003 mov r1, r3 9184: e1a0300c mov r3, ip 9188:    eaffffff     b    918c <__aeabi_cdcmpeq> 0000918c <__aeabi_cdcmpeq>: 918c: e92d4001 push {r0, lr} 9190:    ebffffd4     bl    90e8 <__cmpdf2>
    9194:    e3500000     cmp    r0, #0
    9198:    43700000     cmnmi    r0, #0 919c: e8bd8001 pop {r0, pc} 000091a0 <__aeabi_dcmpeq>: 91a0: e52de008 str lr, [sp, #-8]! 91a4: ebfffff8 bl 918c <__aeabi_cdcmpeq> 91a8: 03a00001 moveq r0, #1 91ac: 13a00000 movne r0, #0 91b0: e49df008 ldr pc, [sp], #8 000091b4 <__aeabi_dcmplt>: 91b4: e52de008 str lr, [sp, #-8]! 91b8: ebfffff3 bl 918c <__aeabi_cdcmpeq> 91bc: 33a00001 movcc r0, #1 91c0: 23a00000 movcs r0, #0 91c4: e49df008 ldr pc, [sp], #8 000091c8 <__aeabi_dcmple>: 91c8: e52de008 str lr, [sp, #-8]! 91cc: ebffffee bl 918c <__aeabi_cdcmpeq> 91d0: 93a00001 movls r0, #1 91d4: 83a00000 movhi r0, #0 91d8: e49df008 ldr pc, [sp], #8 000091dc <__aeabi_dcmpge>: 91dc: e52de008 str lr, [sp, #-8]! 91e0: ebffffe2 bl 9170 <__aeabi_cdrcmple> 91e4: 93a00001 movls r0, #1 91e8: 83a00000 movhi r0, #0 91ec: e49df008 ldr pc, [sp], #8 000091f0 <__aeabi_dcmpgt>: 91f0: e52de008 str lr, [sp, #-8]! 91f4: ebffffdd bl 9170 <__aeabi_cdrcmple> 91f8: 33a00001 movcc r0, #1 91fc: 23a00000 movcs r0, #0
    9200:    e49df008     ldr    pc, [sp], #8

00009204 <__aeabi_d2iz>: 9204:    e1a02081     lsl    r2, r1, #1
    9208:    e2922602     adds    r2, r2, #2097152    ; 0x200000 920c: 2a00000c bcs 9244 <__aeabi_d2iz+0x40>
    9210:    5a000009     bpl    923c <__aeabi_d2iz+0x38>
    9214:    e3e03e3e     mvn    r3, #992    ; 0x3e0
    9218:    e0532ac2     subs    r2, r3, r2, asr #21 921c: 9a00000a bls 924c <__aeabi_d2iz+0x48>
    9220:    e1a03581     lsl    r3, r1, #11
    9224:    e3833102     orr    r3, r3, #-2147483648    ; 0x80000000
    9228:    e1833aa0     orr    r3, r3, r0, lsr #21 922c: e3110102 tst r1, #-2147483648    ; 0x80000000
    9230: e1a00233 lsr r0, r3, r2 9234:    12600000     rsbne    r0, r0, #0
    9238: e12fff1e bx lr 923c: e3a00000 mov r0, #0
    9240: e12fff1e bx lr 9244:    e1900601     orrs    r0, r0, r1, lsl #12
    9248:    1a000002     bne    9258 <__aeabi_d2iz+0x54> 924c: e2110102 ands r0, r1, #-2147483648    ; 0x80000000
    9250:    03e00102     mvneq    r0, #-2147483648    ; 0x80000000
    9254: e12fff1e bx lr 9258:    e3a00000     mov    r0, #0 925c: e12fff1e bx lr 00009260 <__libc_csu_init>: 9260: e92d47f0 push {r4, r5, r6, r7, r8, r9, sl, lr} 9264: e1a0a000 mov sl, r0 9268: e1a08001 mov r8, r1 926c: e1a07002 mov r7, r2 9270:    e59f40a8     ldr    r4, [pc, #168]    ; 9320 <__libc_csu_init+0xc0>
    9274:    ebfffc43     bl    8388 <_init>
    9278:    e59f10a4     ldr    r1, [pc, #164]    ; 9324 <__libc_csu_init+0xc4> 927c: e08f4004 add r4, pc, r4 9280: e08f0001 add r0, pc, r1 9284: e0649000 rsb r9, r4, r0 9288:    e1b09149     asrs    r9, r9, #2 928c: 08bd87f0 popeq {r4, r5, r6, r7, r8, r9, sl, pc} 9290:    e3a06001     mov    r6, #1
    9294:    e4943004     ldr    r3, [r4], #4
    9298: e1a0000a mov r0, sl 929c: e1a01008 mov r1, r8 92a0: e1a02007 mov r2, r7 92a4: e2495001 sub r5, r9, #1 92a8: e12fff33 blx r3 92ac: e1560009 cmp r6, r9 92b0: e0055006 and r5, r5, r6 92b4: 08bd87f0 popeq {r4, r5, r6, r7, r8, r9, sl, pc} 92b8: e3550000 cmp r5, #0 92bc: 0a000007 beq 92e0 <__libc_csu_init+0x80> 92c0: e494c004 ldr ip, [r4], #4 92c4: e1a0000a mov r0, sl 92c8: e1a01008 mov r1, r8 92cc: e1a02007 mov r2, r7 92d0: e3a06002 mov r6, #2 92d4: e12fff3c blx ip 92d8: e1560009 cmp r6, r9 92dc: 08bd87f0 popeq {r4, r5, r6, r7, r8, r9, sl, pc} 92e0: e1a05004 mov r5, r4 92e4: e4953004 ldr r3, [r5], #4 92e8: e1a0000a mov r0, sl 92ec: e1a01008 mov r1, r8 92f0: e1a02007 mov r2, r7 92f4: e12fff33 blx r3 92f8: e2866002 add r6, r6, #2 92fc: e594c004 ldr ip, [r4, #4] 9300: e1a0000a mov r0, sl 9304: e1a01008 mov r1, r8 9308: e1a02007 mov r2, r7 930c: e12fff3c blx ip 9310: e1560009 cmp r6, r9 9314:    e2854004     add    r4, r5, #4
    9318:    1afffff0     bne    92e0 <__libc_csu_init+0x80> 931c: e8bd87f0 pop {r4, r5, r6, r7, r8, r9, sl, pc} 9320:    00008184     .word    0x00008184
    9324:    00008184     .word    0x00008184

00009328 <__libc_csu_fini>: 9328: e12fff1e bx lr Disassembly of section .fini: 0000932c <_fini>: 932c: e92d4008 push {r3, lr} 9330:    e8bd8008     pop    {r3, pc}

arm-none-linux-gnueabi-objdump -d soft.bin > objdump_soft.txt

/* arm-none-linux-gnueabi-objdump -d softfp.bin > objdump_softfp.txt */ softfp.bin: file format elf32-littlearm Disassembly of section .init: 00008388 <_init>: 8388: e92d4008 push {r3, lr} 838c: eb000024 bl 8424 <call_gmon_start>
    8390: e8bd8008 pop {r3, pc} Disassembly of section .plt: 00008394 <.plt>: 8394:    e52de004     push    {lr}        ; (str lr, [sp, #-4]!) 8398:    e59fe004     ldr    lr, [pc, #4]    ; 83a4 <_init+0x1c> 839c: e08fe00e add lr, pc, lr 83a0: e5bef008 ldr pc, [lr, #8]! 83a4: 0000865c .word 0x0000865c 83a8: e28fc600 add ip, pc, #0, 12 83ac: e28cca08 add ip, ip, #8, 20    ; 0x8000 83b0: e5bcf65c ldr pc, [ip, #1628]!    ; 0x65c 83b4: e28fc600 add ip, pc, #0, 12 83b8: e28cca08 add ip, ip, #8, 20    ; 0x8000 83bc: e5bcf654 ldr pc, [ip, #1620]!    ; 0x654 83c0: e28fc600 add ip, pc, #0, 12 83c4: e28cca08 add ip, ip, #8, 20    ; 0x8000 83c8: e5bcf64c ldr pc, [ip, #1612]!    ; 0x64c 83cc: e28fc600 add ip, pc, #0, 12 83d0: e28cca08 add ip, ip, #8, 20    ; 0x8000 83d4: e5bcf644 ldr pc, [ip, #1604]!    ; 0x644 83d8: e28fc600 add ip, pc, #0, 12 83dc: e28cca08 add ip, ip, #8, 20    ; 0x8000 83e0: e5bcf63c ldr pc, [ip, #1596]!    ; 0x63c Disassembly of section .text: 000083e8 <_start>: 83e8: e3a0b000 mov fp, #0 83ec: e3a0e000 mov lr, #0 83f0: e49d1004 pop {r1} ; (ldr r1, [sp], #4) 83f4: e1a0200d mov r2, sp 83f8: e52d2004 push {r2} ; (str r2, [sp, #-4]!) 83fc: e52d0004 push {r0} ; (str r0, [sp, #-4]!) 8400:    e59fc010     ldr    ip, [pc, #16]    ; 8418 <_start+0x30>
    8404:    e52dc004     push    {ip}        ; (str ip, [sp, #-4]!) 8408:    e59f000c     ldr    r0, [pc, #12]    ; 841c <_start+0x34> 840c: e59f300c ldr r3, [pc, #12]    ; 8420 <_start+0x38>
    8410:    ebffffe7     bl    83b4 <_init+0x2c>
    8414:    ebffffef     bl    83d8 <_init+0x50>
    8418:    00008830     .word    0x00008830 841c: 00008590     .word    0x00008590
    8420:    00008768     .word    0x00008768

00008424 <call_gmon_start>: 8424:    e59f0014     ldr    r0, [pc, #20]    ; 8440 <call_gmon_start+0x1c>
    8428:    e59f2014     ldr    r2, [pc, #20]    ; 8444 <call_gmon_start+0x20> 842c: e08f3000 add r3, pc, r0 8430: e7933002 ldr r3, [r3, r2] 8434:    e3530000     cmp    r3, #0
    8438: 012fff1e bxeq lr 843c: eaffffdf b 83c0 <_init+0x38>
    8440:    000085cc     .word    0x000085cc
    8444:    00000020     .word    0x00000020

00008448 <__do_global_dtors_aux>: 8448:    e59f3010     ldr    r3, [pc, #16]    ; 8460 <__do_global_dtors_aux+0x18> 844c: e5d32000 ldrb r2, [r3] 8450:    e3520000     cmp    r2, #0
    8454:    03a02001     moveq    r2, #1
    8458: 05c32000 strbeq r2, [r3] 845c: e12fff1e bx lr 8460:    00010a2c     .word    0x00010a2c

00008464 <frame_dummy>: 8464:    e59f0020     ldr    r0, [pc, #32]    ; 848c <frame_dummy+0x28>
    8468: e92d4008 push {r3, lr} 846c: e5903000 ldr r3, [r0] 8470:    e3530000     cmp    r3, #0
    8474: 08bd8008 popeq {r3, pc} 8478:    e59f3010     ldr    r3, [pc, #16]    ; 8490 <frame_dummy+0x2c> 847c: e3530000 cmp r3, #0
    8480: 08bd8008 popeq {r3, pc} 8484: e12fff33 blx r3 8488: e8bd8008 pop {r3, pc} 848c: 00010904     .word    0x00010904 ... 00008498 <ln>: 8498:    e52db004     push    {fp}        ; (str fp, [sp, #-4]!) 849c: e28db000 add fp, sp, #0 84a0: e24dd034 sub sp, sp, #52    ; 0x34 84a4: e14b03f4 strd r0, [fp, #-52]    ; 0xffffffcc 84a8: e3a0300f mov r3, #15 84ac: e50b3018 str r3, [fp, #-24]    ; 0xffffffe8 84b0: ed1b6b0d vldr d6, [fp, #-52]    ; 0xffffffcc 84b4: ed9f7b33 vldr d7, [pc, #204]    ; 8588 <ln+0xf0> 84b8: ee365b47 vsub.f64 d5, d6, d7 84bc: ed1b6b0d vldr d6, [fp, #-52]    ; 0xffffffcc 84c0: ed9f7b30 vldr d7, [pc, #192]    ; 8588 <ln+0xf0> 84c4: ee366b07 vadd.f64 d6, d6, d7 84c8: ee857b06 vdiv.f64 d7, d5, d6 84cc: ed0b7b09 vstr d7, [fp, #-36]    ; 0xffffffdc 84d0: ed1b6b09 vldr d6, [fp, #-36]    ; 0xffffffdc 84d4: ed1b7b09 vldr d7, [fp, #-36]    ; 0xffffffdc 84d8: ee267b07 vmul.f64 d7, d6, d7 84dc: ed0b7b0b vstr d7, [fp, #-44]    ; 0xffffffd4 84e0: e51b3018 ldr r3, [fp, #-24]    ; 0xffffffe8 84e4: e1a03083 lsl r3, r3, #1 84e8: e2833001 add r3, r3, #1 84ec: e50b300c str r3, [fp, #-12] 84f0: e51b300c ldr r3, [fp, #-12] 84f4: ee073a90 vmov s15, r3 84f8: eeb86be7 vcvt.f64.s32 d6, s15 84fc: ed9f5b21 vldr d5, [pc, #132]    ; 8588 <ln+0xf0>
    8500: ee857b06 vdiv.f64 d7, d5, d6 8504:    ed0b7b05     vstr    d7, [fp, #-20]    ; 0xffffffec
    8508:    e51b3018     ldr    r3, [fp, #-24]    ; 0xffffffe8 850c: e50b3008 str r3, [fp, #-8] 8510:    ea00000f     b    8554 <ln+0xbc>
    8514:    e51b300c     ldr    r3, [fp, #-12] 8518:    e2433002     sub    r3, r3, #2 851c: e50b300c str r3, [fp, #-12] 8520:    e51b300c     ldr    r3, [fp, #-12] 8524: ee063a90 vmov s13, r3 8528: eeb87be6 vcvt.f64.s32 d7, s13 852c: ed9f5b15 vldr d5, [pc, #84]    ; 8588 <ln+0xf0>
    8530: ee856b07 vdiv.f64 d6, d5, d7 8534:    ed1b5b0b     vldr    d5, [fp, #-44]    ; 0xffffffd4
    8538:    ed1b7b05     vldr    d7, [fp, #-20]    ; 0xffffffec 853c: ee257b07 vmul.f64 d7, d5, d7 8540: ee367b07 vadd.f64 d7, d6, d7 8544:    ed0b7b05     vstr    d7, [fp, #-20]    ; 0xffffffec
    8548:    e51b3008     ldr    r3, [fp, #-8] 854c: e2433001 sub r3, r3, #1
    8550:    e50b3008     str    r3, [fp, #-8] 8554:    e51b3008     ldr    r3, [fp, #-8] 8558:    e3530000     cmp    r3, #0 855c: caffffec bgt 8514 <ln+0x7c>
    8560:    ed1b7b09     vldr    d7, [fp, #-36]    ; 0xffffffdc
    8564: ee376b07 vadd.f64 d6, d7, d7 8568:    ed1b7b05     vldr    d7, [fp, #-20]    ; 0xffffffec 856c: ee267b07 vmul.f64 d7, d6, d7 8570: ec532b17 vmov r2, r3, d7 8574: e1a00002 mov r0, r2 8578: e1a01003 mov r1, r3 857c: e28bd000 add sp, fp, #0
    8580: e8bd0800 pop {fp} 8584: e12fff1e bx lr 8588:    00000000     .word    0x00000000 858c: 3ff00000 .word 0x3ff00000

00008590 <main>: 8590: e92d4800 push {fp, lr} 8594:    e28db004     add    fp, sp, #4
    8598:    e24dd030     sub    sp, sp, #48    ; 0x30 859c: e3a03000 mov r3, #0 85a0: e50b3024 str r3, [fp, #-36]    ; 0xffffffdc 85a4: e3a03000 mov r3, #0 85a8: e50b3020 str r3, [fp, #-32]    ; 0xffffffe0 85ac: e3a03000 mov r3, #0 85b0: e50b302c str r3, [fp, #-44]    ; 0xffffffd4 85b4: e3a03000 mov r3, #0 85b8: e50b3028 str r3, [fp, #-40]    ; 0xffffffd8 85bc: e3a00002 mov r0, #2 85c0: e24b3024 sub r3, fp, #36    ; 0x24 85c4: e1a01003 mov r1, r3 85c8: ebffff7f bl 83cc <_init+0x44> 85cc: e28f3f53 add r3, pc, #332    ; 0x14c 85d0: e1c320d0 ldrd r2, [r3] 85d4: e14b21f4 strd r2, [fp, #-20]    ; 0xffffffec 85d8: ea00001e b 8658 <main+0xc8> 85dc: ed1b6b05 vldr d6, [fp, #-20]    ; 0xffffffec 85e0: ed9f7b50 vldr d7, [pc, #320]    ; 8728 <main+0x198> 85e4: ee266b07 vmul.f64 d6, d6, d7 85e8: e28f3d05 add r3, pc, #320    ; 0x140 85ec: e1c320d0 ldrd r2, [r3] 85f0: ed1b7b05 vldr d7, [fp, #-20]    ; 0xffffffec 85f4: ec432b15 vmov d5, r2, r3 85f8: ee355b47 vsub.f64 d5, d5, d7 85fc: ee867b05 vdiv.f64 d7, d6, d5 8600:    ed0b7b07     vstr    d7, [fp, #-28]    ; 0xffffffe4
    8604:    ed1b5b07     vldr    d5, [fp, #-28]    ; 0xffffffe4
    8608:    ed9f6b4a     vldr    d6, [pc, #296]    ; 8738 <main+0x1a8> 860c: ee857b06 vdiv.f64 d7, d5, d6 8610: ec510b17 vmov r0, r1, d7 8614:    ebffff9f     bl    8498 <ln>
    8618: ec410b15 vmov d5, r0, r1 861c: ed9f6b47 vldr d6, [pc, #284]    ; 8740 <main+0x1b0>
    8620: ee857b06 vdiv.f64 d7, d5, d6 8624:    ed9f6b47     vldr    d6, [pc, #284]    ; 8748 <main+0x1b8>
    8628: ee376b06 vadd.f64 d6, d7, d6 862c: ed9f5b3b vldr d5, [pc, #236]    ; 8720 <main+0x190>
    8630: ee857b06 vdiv.f64 d7, d5, d6 8634:    ed9f6b45     vldr    d6, [pc, #276]    ; 8750 <main+0x1c0>
    8638: ee377b46 vsub.f64 d7, d7, d6 863c: eefd6bc7 vcvt.s32.f64 s13, d7 8640: ee163a90 vmov r3, s13 8644:    e50b3008     str    r3, [fp, #-8] 8648:    ed1b6b05     vldr    d6, [fp, #-20]    ; 0xffffffec 864c: ed9f7b33 vldr d7, [pc, #204]    ; 8720 <main+0x190>
    8650: ee367b07 vadd.f64 d7, d6, d7 8654:    ed0b7b05     vstr    d7, [fp, #-20]    ; 0xffffffec
    8658:    ed1b6b05     vldr    d6, [fp, #-20]    ; 0xffffffec 865c: ed9f7b33 vldr d7, [pc, #204]    ; 8730 <main+0x1a0>
    8660: eeb46bc7 vcmpe.f64 d6, d7 8664: eef1fa10 vmrs APSR_nzcv, fpscr 8668:    53a03000     movpl    r3, #0 866c: 43a03001 movmi r3, #1
    8670:    e20330ff     and    r3, r3, #255    ; 0xff
    8674:    e3530000     cmp    r3, #0
    8678:    1affffd7     bne    85dc <main+0x4c> 867c: e3a00002 mov r0, #2
    8680:    e24b302c     sub    r3, fp, #44    ; 0x2c
    8684: e1a01003 mov r1, r3 8688:    ebffff4f     bl    83cc <_init+0x44> 868c: e59f10c4 ldr r1, [pc, #196]    ; 8758 <main+0x1c8>
    8690:    e51b2024     ldr    r2, [fp, #-36]    ; 0xffffffdc
    8694:    e51b3020     ldr    r3, [fp, #-32]    ; 0xffffffe0
    8698: e1a00001 mov r0, r1 869c: e1a01002 mov r1, r2 86a0: e1a02003 mov r2, r3 86a4: ebffff3f bl 83a8 <_init+0x20> 86a8: e59f10ac ldr r1, [pc, #172]    ; 875c <main+0x1cc> 86ac: e51b202c ldr r2, [fp, #-44]    ; 0xffffffd4 86b0: e51b3028 ldr r3, [fp, #-40]    ; 0xffffffd8 86b4: e1a00001 mov r0, r1 86b8: e1a01002 mov r1, r2 86bc: e1a02003 mov r2, r3 86c0: ebffff38 bl 83a8 <_init+0x20> 86c4: e59f0094 ldr r0, [pc, #148]    ; 8760 <main+0x1d0> 86c8: e51b202c ldr r2, [fp, #-44]    ; 0xffffffd4 86cc: e51b3024 ldr r3, [fp, #-36]    ; 0xffffffdc 86d0: e0632002 rsb r2, r3, r2 86d4: e51b1028 ldr r1, [fp, #-40]    ; 0xffffffd8 86d8: e51b3020 ldr r3, [fp, #-32]    ; 0xffffffe0 86dc: e0633001 rsb r3, r3, r1 86e0: e1a01000 mov r1, r0 86e4: e1a00001 mov r0, r1 86e8: e1a01002 mov r1, r2 86ec: e1a02003 mov r2, r3 86f0: ebffff2c bl 83a8 <_init+0x20> 86f4: e59f2068 ldr r2, [pc, #104]    ; 8764 <main+0x1d4> 86f8: e51b3008 ldr r3, [fp, #-8] 86fc: e58d3000 str r3, [sp] 8700: e1a03002 mov r3, r2 8704: e1a00003 mov r0, r3 8708:    e14b21d4     ldrd    r2, [fp, #-20]    ; 0xffffffec 870c: ebffff25 bl 83a8 <_init+0x20>
    8710:    e3a03000     mov    r3, #0
    8714: e1a00003 mov r0, r3 8718:    e24bd004     sub    sp, fp, #4 871c: e8bd8800 pop {fp, pc} 8720:    00000000     .word    0x00000000
    8724:    3ff00000     .word    0x3ff00000
    8728:    00000000     .word    0x00000000 872c: 40e6f300 .word 0x40e6f300
    8730:    00000000     .word    0x00000000
    8734:    409c2000     .word    0x409c2000
    8738:    00000000     .word    0x00000000 873c: 40c38800 .word 0x40c38800
    8740:    00000000     .word    0x00000000
    8744:    40aedc00     .word    0x40aedc00
    8748:    dcb5db83     .word    0xdcb5db83 874c: 3f6b79e1 .word 0x3f6b79e1
    8750:    66666666     .word    0x66666666
    8754:    40711266     .word    0x40711266
    8758:    00008840     .word    0x00008840 875c: 0000885c .word 0x0000885c
    8760:    00008878     .word    0x00008878
    8764:    00008890     .word    0x00008890

00008768 <__libc_csu_init>: 8768: e92d47f0 push {r4, r5, r6, r7, r8, r9, sl, lr} 876c: e1a0a000 mov sl, r0 8770: e1a08001 mov r8, r1 8774: e1a07002 mov r7, r2 8778:    e59f40a8     ldr    r4, [pc, #168]    ; 8828 <__libc_csu_init+0xc0> 877c: ebffff01 bl 8388 <_init>
    8780:    e59f10a4     ldr    r1, [pc, #164]    ; 882c <__libc_csu_init+0xc4>
    8784: e08f4004 add r4, pc, r4 8788: e08f0001 add r0, pc, r1 878c: e0649000 rsb r9, r4, r0 8790:    e1b09149     asrs    r9, r9, #2
    8794: 08bd87f0 popeq {r4, r5, r6, r7, r8, r9, sl, pc} 8798:    e3a06001     mov    r6, #1 879c: e4943004 ldr r3, [r4], #4 87a0: e1a0000a mov r0, sl 87a4: e1a01008 mov r1, r8 87a8: e1a02007 mov r2, r7 87ac: e2495001 sub r5, r9, #1 87b0: e12fff33 blx r3 87b4: e1560009 cmp r6, r9 87b8: e0055006 and r5, r5, r6 87bc: 08bd87f0 popeq {r4, r5, r6, r7, r8, r9, sl, pc} 87c0: e3550000 cmp r5, #0 87c4: 0a000007 beq 87e8 <__libc_csu_init+0x80> 87c8: e494c004 ldr ip, [r4], #4 87cc: e1a0000a mov r0, sl 87d0: e1a01008 mov r1, r8 87d4: e1a02007 mov r2, r7 87d8: e3a06002 mov r6, #2 87dc: e12fff3c blx ip 87e0: e1560009 cmp r6, r9 87e4: 08bd87f0 popeq {r4, r5, r6, r7, r8, r9, sl, pc} 87e8: e1a05004 mov r5, r4 87ec: e4953004 ldr r3, [r5], #4 87f0: e1a0000a mov r0, sl 87f4: e1a01008 mov r1, r8 87f8: e1a02007 mov r2, r7 87fc: e12fff33 blx r3 8800:    e2866002     add    r6, r6, #2
    8804:    e594c004     ldr    ip, [r4, #4] 8808: e1a0000a mov r0, sl 880c: e1a01008 mov r1, r8 8810: e1a02007 mov r2, r7 8814: e12fff3c blx ip 8818: e1560009 cmp r6, r9 881c: e2854004 add r4, r5, #4
    8820:    1afffff0     bne    87e8 <__libc_csu_init+0x80>
    8824: e8bd87f0 pop {r4, r5, r6, r7, r8, r9, sl, pc} 8828:    00008170     .word    0x00008170 882c: 00008170     .word    0x00008170

00008830 <__libc_csu_fini>: 8830: e12fff1e bx lr Disassembly of section .fini: 00008834 <_fini>: 8834: e92d4008 push {r3, lr} 8838:    e8bd8008     pop    {r3, pc}

arm-none-linux-gnueabi-objdump -d softfp.bin > objdump_softfp.txt

分別執行bin文件：

能夠看出相差一個數量級硬浮點2.7ms，軟浮點29.5ms，性能仍是差距很大的！

2.驅動程序

代碼以下：

#include <linux/module.h> #include <linux/configfs.h> #include <linux/init.h> #include <linux/kernel.h>

static double ln(double a) { int N = 15; int k,nk; double x,xx,y; x = (a-1)/(a+1); xx = x*x; nk = 2*N+1; y = 1.0/nk; for(k=N;k>0;k--) { nk = nk - 2; y = 1.0/nk+xx*y; } return 2.0*x*y; } static int hello_init(void) { int t1, force2int; double Rt, Vadc; struct timespec time_start={0, 0},time_end={0, 0}; double a; a = 3.9; a = a*a; printk("Hello,world! %f\n", a); printk("Hello,world! %d\n", a); printk("Hello,world! %d\n", (int)a); time_start = current_kernel_time(); /* 根據採樣電壓反推熱敏電阻的溫度 */
    for(Vadc=1; Vadc<1800; Vadc++) { Rt = Vadc * 47000 / (1800-Vadc); t1=1/(ln(Rt/10000)/3950+1/298.15)-273.15; } time_end = current_kernel_time(); printk("start time %ld s,%ld ns\n", time_start.tv_sec, time_start.tv_nsec); printk("end time %ld s,%ld ns\n", time_end.tv_sec, time_end.tv_nsec); printk("duration:%ld s %ld ns\n", time_end.tv_sec-time_start.tv_sec, time_end.tv_nsec-time_start.tv_nsec); force2int = (int)Vadc; printk("%d = %d\n", force2int, t1); return 0; } static void hello_exit(void) { printk("Goodbye,cruel world!\n"); } module_init(hello_init); module_exit(hello_exit); MODULE_AUTHOR("Vedic <FZKmxcz@163.com>"); MODULE_LICENSE("Dual BSD/GPL");

Makefile：

obj-m +=driver_test.o driver_test-objs:= hello.o KDIR:=/home/fuzk/project/Prolin/firmware_4/build_dir/linux-sc9820_sc9820_pax/linux-3.10.65 COMPILER=/opt/toolchain/arm-2012.03/bin/arm-none-linux-gnueabi-gcc LD_PATH=/opt/toolchain/arm-2012.03/bin/arm-none-linux-gnueabi-ld AR_PATH=/opt/toolchain/arm-2012.03/bin/arm-none-linux-gnueabi-ar ARCH_TYPE=arm ccflags-y += -mfloat-abi=softfp ldflags-y += -L/opt/toolchain/arm-2012.03/lib/gcc/arm-none-linux-gnueabi/4.6.3 -lgcc -static all: make CC=$(COMPILER) LD=$(LD_PATH) AR=$(AR_PATH) ARCH=$(ARCH_TYPE) -C $(KDIR)  M=$(PWD) modules clean: make CC=$(COMPILER) LD=$(LD_PATH) ARCH=$(ARCH_TYPE) -C $(KDIR)  M=$(PWD)  clean

　　因爲是驅動因此得寫個Makefile，同時printk不支持打印浮點數格式，只能先強制類型轉換int再打印，不然打印的數值是錯的，待會貼log就能夠看出來

運行時間以下：

　　這裏須要注意的是：驅動在內核態，進程不會被切出去（最多task_struct結構體的flag被標誌NEED_RESHEDULE），且只有中斷才能打斷其執行

而時間函數current_kernel_time()更新的步進應該是每10ms產生一箇中斷，因此在中斷前執行完讀出來的時間戳是同樣的，或者在中斷完成後讀到

更新後的時間戳，總而言之該時間函數精度爲10ms，測試幾回出來發現要麼0要麼近10ms能夠推測這段代碼執行時間小於10ms！

　　反彙編發現彙編指令跟應用程序的硬浮點是同樣的，因此推測時間也在2.7ms左右

/* arm-none-linux-gnueabi-objdump -d driver_test.o > objdump_softfp.txt */ driver_test.o: file format elf32-littlearm Disassembly of section .text: 00000000 <init_module>: 0: e92d41f0 push {r4, r5, r6, r7, r8, lr} 4: ed2d8b02 vpush {d8} 8:    e24dd010     sub    sp, sp, #16 c: e59f217c ldr r2, [pc, #380]    ; 190 <init_module+0x190>
  10:    e59f317c     ldr    r3, [pc, #380]    ; 194 <init_module+0x194>
  14:    e59f017c     ldr    r0, [pc, #380]    ; 198 <init_module+0x198>
  18:    ebfffffe     bl    0 <printk> 1c: ed9f8b4b vldr d8, [pc, #300]    ; 150 <init_module+0x150>
  20:    e59f2168     ldr    r2, [pc, #360]    ; 190 <init_module+0x190>
  24:    e59f3168     ldr    r3, [pc, #360]    ; 194 <init_module+0x194>
  28:    e59f016c     ldr    r0, [pc, #364]    ; 19c <init_module+0x19c> 2c: ebfffffe bl 0 <printk>
  30:    e3a0100f     mov    r1, #15
  34:    e59f0160     ldr    r0, [pc, #352]    ; 19c <init_module+0x19c>
  38:    ebfffffe     bl    0 <printk> 3c: e1a0000d mov r0, sp 40:    ebfffffe     bl    0 <current_kernel_time>
  44: e59d7000 ldr r7, [sp] 48:    e59d5004     ldr    r5, [sp, #4] 4c: eeb02b48 vmov.f64 d2, d8 50:    ea000021     b    dc <init_module+0xdc>
  54:    ed9f0b3f     vldr    d0, [pc, #252]    ; 158 <init_module+0x158>
  58: ee366b48 vsub.f64 d6, d6, d8 5c: ed9f7b3f vldr d7, [pc, #252]    ; 160 <init_module+0x160>
  60:    e3a0301f     mov    r3, #31
  64:    ed9f4b3f     vldr    d4, [pc, #252]    ; 168 <init_module+0x168>
  68: ee280b00 vmul.f64 d0, d8, d0 6c: ee806b06 vdiv.f64 d6, d0, d6 70: ee866b07 vdiv.f64 d6, d6, d7 74: ee367b42 vsub.f64 d7, d6, d2 78: ee366b02 vadd.f64 d6, d6, d2 7c: ee876b06 vdiv.f64 d6, d7, d6 80: ee265b06 vmul.f64 d5, d6, d6 84:    e2433002     sub    r3, r3, #2
  88:    ed9f3b30     vldr    d3, [pc, #192]    ; 150 <init_module+0x150> 8c: e3530001 cmp r3, #1
  90: ee013a10 vmov s2, r3 94: eeb87bc1 vcvt.f64.s32 d7, s2 98: ee827b07 vdiv.f64 d7, d2, d7 9c: eeb01b47 vmov.f64 d1, d7 a0: ee051b04 vmla.f64 d1, d5, d4 a4: eeb04b41 vmov.f64 d4, d1 a8: 1afffff5 bne 84 <init_module+0x84> ac: ee360b06 vadd.f64 d0, d6, d6 b0: ed9f6b2e vldr d6, [pc, #184]    ; 170 <init_module+0x170> b4: ed9f5b2f vldr d5, [pc, #188]    ; 178 <init_module+0x178> b8: ee207b01 vmul.f64 d7, d0, d1 bc: ee877b06 vdiv.f64 d7, d7, d6 c0: ed9f6b2e vldr d6, [pc, #184]    ; 180 <init_module+0x180> c4: ee374b05 vadd.f64 d4, d7, d5 c8: ee834b04 vdiv.f64 d4, d3, d4 cc: ee347b46 vsub.f64 d7, d4, d6 d0: eefd1bc7 vcvt.s32.f64 s3, d7 d4: ee114a90 vmov r4, s3 d8: ee388b03 vadd.f64 d8, d8, d3 dc: ed9f6b29 vldr d6, [pc, #164]    ; 188 <init_module+0x188> e0: eeb48bc6 vcmpe.f64 d8, d6 e4: eef1fa10 vmrs APSR_nzcv, fpscr e8: 4affffd9 bmi 54 <init_module+0x54> ec: e28d0008 add r0, sp, #8 f0: ebfffffe bl 0 <current_kernel_time> f4: e59d8008 ldr r8, [sp, #8] f8: e59d600c ldr r6, [sp, #12] fc: e1a01007 mov r1, r7 100: e1a02005 mov r2, r5 104:    e59f0094     ldr    r0, [pc, #148]    ; 1a0 <init_module+0x1a0>
 108:    ebfffffe     bl    0 <printk> 10c: e1a01008 mov r1, r8 110: e1a02006 mov r2, r6 114:    e59f0088     ldr    r0, [pc, #136]    ; 1a4 <init_module+0x1a4>
 118:    ebfffffe     bl    0 <printk> 11c: e0671008 rsb r1, r7, r8 120: e0652006 rsb r2, r5, r6 124:    e59f007c     ldr    r0, [pc, #124]    ; 1a8 <init_module+0x1a8>
 128:    ebfffffe     bl    0 <printk> 12c: eefd3bc8 vcvt.s32.f64 s7, d8 130: e1a02004 mov r2, r4 134:    e59f0070     ldr    r0, [pc, #112]    ; 1ac <init_module+0x1ac>
 138: ee131a90 vmov r1, s7 13c: ebfffffe bl 0 <printk>
 140:    e3a00000     mov    r0, #0
 144:    e28dd010     add    sp, sp, #16
 148: ecbd8b02 vpop {d8} 14c: e8bd81f0 pop {r4, r5, r6, r7, r8, pc} 150:    00000000     .word    0x00000000
 154:    3ff00000     .word    0x3ff00000
 158:    00000000     .word    0x00000000 15c: 40e6f300 .word 0x40e6f300
 160:    00000000     .word    0x00000000
 164:    40c38800     .word    0x40c38800
 168:    08421084     .word    0x08421084 16c: 3fa08421 .word 0x3fa08421
 170:    00000000     .word    0x00000000
 174:    40aedc00     .word    0x40aedc00
 178:    dcb5db83     .word    0xdcb5db83 17c: 3f6b79e1 .word 0x3f6b79e1
 180:    66666666     .word    0x66666666
 184:    40711266     .word    0x40711266
 188:    00000000     .word    0x00000000 18c: 409c2000 .word 0x409c2000
 190:    1eb851eb     .word    0x1eb851eb
 194:    402e6b85     .word    0x402e6b85
 198:    00000000     .word    0x00000000 19c: 00000011     .word    0x00000011 1a0: 00000022     .word    0x00000022 1a4: 0000003b .word 0x0000003b 1a8: 00000054     .word    0x00000054 1ac: 0000006b .word 0x0000006b 000001b0 <cleanup_module>: 1b0: e59f0000 ldr r0, [pc] ; 1b8 <cleanup_module+0x8> 1b4: eafffffe b 0 <printk> 1b8: 00000074     .word    0x00000074 1bc: e320f000 nop {0}

arm-none-linux-gnueabi-objdump -d driver_test.o > objdump_softfp.txt

　　Makefile修改浮點爲軟浮點時候，連接警告，缺乏上面說的函數，能夠我已經連接了libgcc.a，不知道爲什麼仍是警告找不到，所以就沒深究了（懷疑這個庫是應用專用）

ccflags-y += -mfloat-abi=soft 連接警告： WARNING: "__aeabi_d2iz" [/home/fuzk/test/bokeyuan/float/driver/driver_test.ko] undefined! WARNING: "__aeabi_i2d" [/home/fuzk/test/bokeyuan/float/driver/driver_test.ko] undefined! WARNING: "__aeabi_dsub" [/home/fuzk/test/bokeyuan/float/driver/driver_test.ko] undefined! WARNING: "__aeabi_dadd" [/home/fuzk/test/bokeyuan/float/driver/driver_test.ko] undefined! WARNING: "__aeabi_dmul" [/home/fuzk/test/bokeyuan/float/driver/driver_test.ko] undefined! WARNING: "__aeabi_ddiv" [/home/fuzk/test/bokeyuan/float/driver/driver_test.ko] undefined! WARNING: "__aeabi_dcmplt" [/home/fuzk/test/bokeyuan/float/driver/driver_test.ko] undefined!加載失敗：[ 1780.809417] c0 double: Unknown symbol __aeabi_ddiv (err 0)[ 1780.815002] c0 double: Unknown symbol __aeabi_dmul (err 0)[ 1780.820495] c0 double: Unknown symbol __aeabi_dadd (err 0)[ 1780.826049] c0 double: Unknown symbol __aeabi_dsub (err 0)[ 1780.831512] c0 double: Unknown symbol __aeabi_i2d (err 0)insmod: can't insert 'driver_test.ko': unknown symbol in module, or unknown parameter