樹莓派4B的CPU系統裏查到爲BCM2835而非BCM2711

樹莓派4B採用四核64位的ARM Cortex-A72架構CPU，型號爲博通BCM2711 SoC。2711是個64位的四核，而2835是多年前的32位單核CPU。

查看當前芯片版本，顯示爲4核心，可是芯片名字倒是BCM2835，這是一個很老的芯片。

在樹莓派zero和1上使用的，新的樹莓派4B是BCM2711，拿起板子我能明顯看到 芯片上的絲印字，爲何cpuinfo命令查出來的是錯誤的呢？

pi@raspberrypi:/proc/cpu $ cat /proc/cpuinfo

processor : 0

model name : ARMv7 Processor rev 3 (v7l)

BogoMIPS : 108.00

Features : half thumb fastmult vfp edsp neon vfpv3 tls vfpv4 idiva idivt vfpd32 lpae evtstrm crc32

CPU implementer : 0x41

CPU architecture: 7

CPU variant : 0x0

CPU part : 0xd08

CPU revision : 3

 

processor : 1

model name : ARMv7 Processor rev 3 (v7l)

BogoMIPS : 108.00

Features : half thumb fastmult vfp edsp neon vfpv3 tls vfpv4 idiva idivt vfpd32 lpae evtstrm crc32

CPU implementer : 0x41

CPU architecture: 7

CPU variant : 0x0

CPU part : 0xd08

CPU revision : 3

 

processor : 2

model name : ARMv7 Processor rev 3 (v7l)

BogoMIPS : 108.00

Features : half thumb fastmult vfp edsp neon vfpv3 tls vfpv4 idiva idivt vfpd32 lpae evtstrm crc32

CPU implementer : 0x41

CPU architecture: 7

CPU variant : 0x0

CPU part : 0xd08

CPU revision : 3

 

processor : 3

model name : ARMv7 Processor rev 3 (v7l)

BogoMIPS : 108.00

Features : half thumb fastmult vfp edsp neon vfpv3 tls vfpv4 idiva idivt vfpd32 lpae evtstrm crc32

CPU implementer : 0x41

CPU architecture: 7

CPU variant : 0x0

CPU part : 0xd08

CPU revision : 3

 

Hardware : BCM2835

Revision : b03111

Serial : 10000000eb0168e0

Model : Raspberry Pi 4 Model B Rev 1.1

Gordon大佬回覆以下，大意是內核只許設置1個值，若是設置不一樣的值就要改代碼，這會致使上游集成更加麻煩。建議查版本用cat /proc/device-tree/model來看。

Gordon Hollingworth PhD

Raspberry Pi - Director of Software Engineering

https://www.raspberrypi.org/forums/viewtopic.php?p=1190349

 

this, as 6by9 indicated, is due to the fact that the upstream ARM kernel only allows us to set a single value for our devices.

If we wanted to have multiple different values it would require that we edit the code (which in general we prefer not to do because is causes problems for us wen integrating changes from upstream).i've asked Phil to change this to instead return "BCM28xx" to indicate that the kernel is specifically for the BCM2805/6/7 silicon.if you'd like to find out the model of the computer you should use the device tree instead a la:

pi@raspberrypi:~ $ cat /proc/device-tree/model

Raspberry Pi 3 Model B Rev 1.2