topic Re: IMX7d second cpu core not powering up in i.MX Processors

IMX7d second cpu core not powering up

vinothkumareswa — Wed, 20 Sep 2017 08:28:15 GMT

Hi,

I am currently using the Compulab board,

CL-SOM-iMX7 | NXP (Freescale) i.MX 7 | System-on-Module | Computer-on-Module | CompuLab

and trying to run the system with the kernel version:4.9.39.

I have used the Yocto build system (Pyro). I have successfully built the image and can boot the system. But after booting up, I could see that only one CPU core is activated. The log message are as follows:

root@cl-som-imx7:~# dmesg | grep -i cpu
Booting Linux on physical CPU 0x0
CPU: ARMv7 Processor [410fc075] revision 5 (ARMv7), cr=10c5387d
CPU: PIPT / VIPT nonaliasing data cache, VIPT aliasing instruction cache
percpu: Embedded 14 pages/cpu @ab729000 s25996 r8192 d23156 u57344
pcpu-alloc: s25996 r8192 d23156 u57344 alloc=14*4096
pcpu-alloc: [0] 0 [0] 1
SLUB: HWalign=64, Order=0-3, MinObjects=0, CPUs=2, Nodes=1
RCU restricting CPUs from NR_CPUS=4 to nr_cpu_ids=2.
RCU: Adjusting geometry for rcu_fanout_leaf=32, nr_cpu_ids=2
CPU: Testing write buffer coherency: ok
CPU0: update cpu_capacity 1024
CPU0: thread -1, cpu 0, socket 0, mpidr 80000000
Brought up 1 CPUs
CPU: All CPU(s) started in SVC mode.
cpuidle: using governor ladder
cpuidle: using governor menu

cat /proc/cpuinfo
processor       : 0
model name      : ARMv7 Processor rev 5 (v7l)
BogoMIPS        : 48.00
Features        : half thumb fastmult vfp edsp neon vfpv3 tls vfpv4 idiva idivt vfpd32 lpae evtstrm
CPU implementer : 0x41
CPU architecture: 7
CPU variant     : 0x0
CPU part        : 0xc07
CPU revision    : 5

Hardware        : Freescale i.MX7 Dual (Device Tree)
Revision        : 0000
Serial          : 0000000000000000

I have compiled the kernel with Symmetric multiprocessing support. Any information on how to enable the second CPU core would be helpful.

Regards,
Vinothkumar

Re: IMX7d second cpu core not powering up

igorpadykov — Wed, 20 Sep 2017 10:48:05 GMT

Hi Vinothkumar

please check "maxcpus" parameter described in Table 9. Common

kernel boot parameters attached Release Notes. Also one can try with official nxp L4.1.15

releases described on

i.MX 6 / i.MX 7 Series Software and Development Tool|NXP

Best regards
igor
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Re: IMX7d second cpu core not powering up

vinothkumareswa — Wed, 20 Sep 2017 11:48:38 GMT

Hi,

I tried with the kernel parameter maxcpus=2. Still the second CPU core is not powering up.

dmesg | grep -i cpu
Booting Linux on physical CPU 0x0
CPU: ARMv7 Processor [410fc075] revision 5 (ARMv7), cr=10c5387d
CPU: PIPT / VIPT nonaliasing data cache, VIPT aliasing instruction cache
percpu: Embedded 14 pages/cpu @ab725000 s25996 r8192 d23156 u57344
pcpu-alloc: s25996 r8192 d23156 u57344 alloc=14*4096
pcpu-alloc: [0] 0 [0] 1
Kernel command line: console=ttymxc0,115200 root=/dev/mmcblk0p2 rootwait maxcpus=2
SLUB: HWalign=64, Order=0-3, MinObjects=0, CPUs=2, Nodes=1
RCU restricting CPUs from NR_CPUS=4 to nr_cpu_ids=2.
RCU: Adjusting geometry for rcu_fanout_leaf=32, nr_cpu_ids=2
CPU: Testing write buffer coherency: ok
CPU0: update cpu_capacity 1024
CPU0: thread -1, cpu 0, socket 0, mpidr 80000000
Brought up 1 CPUs
CPU: All CPU(s) started in SVC mode.
cpuidle: using governor ladder
cpuidle: using governor menu

I have used the Linux version 4.1.15 from the IMX repository. With that version, I could see both the CPU cores are powering up.

Now, I am trying with the kernel version 4.9.x. With this kernel version, I couldn't run both the CPU cores from the imx7d.

Regards,

vinothkumar

Re: IMX7d second cpu core not powering up

fabio_estevam — Wed, 20 Sep 2017 12:54:49 GMT

Mainline kernel boots in non-secure world, so you need U-Boot to have PSCI to turn on the two cores.

If you want to use a mainline kernel, then please use mainline U-Boot as it has PSCI support for mx7.

Take imx7d sabresd for example, there are two U-Boot defconfigs:

mx7dsabresd_defconfig: Boots in non-secure world (suited for booting a mainline kernel)

mx7dsabresd_secure_defconfig: Boots in secure world (suited for booting NXP 4.1 kernel).

Re: IMX7d second cpu core not powering up

vinothkumareswa — Wed, 20 Sep 2017 13:53:29 GMT

Hi,

Thanks for the information. I would like to have secure boot.

Is there any NXP kernel version greater than 4.5 that supports secure boot.

Regards,

Vinothkumar

Re: IMX7d second cpu core not powering up

fabio_estevam — Wed, 20 Sep 2017 19:14:20 GMT

No, there is not such kernel from NXP currently.

Re: IMX7d second cpu core not powering up

fabio_estevam — Sat, 23 Sep 2017 13:07:43 GMT

Actually NXP has just released a 4.9 based kernel. You can get it from:

http://git.freescale.com/git/cgit.cgi/imx/linux-imx.git/log/?h=imx_4.9.11_1.0.0_ga