On 26 June 2014 16:27, Joel (Xi Zhou) Zhou joel.zhou@broadcom.com wrote:
Hi all,
I’m working on booting Linaro LSK 3.10.40 kernel in be8 mode on our Cortex-A9 system.
There is an issue related to VFP instruction. It complain “vstmia” is an undefined instruction.
The VFP is supported in CPU and CONFIG_VFP and CONFIG_VFPv3 are enabled in kernel config.
Are there any patch need to be done for VFP in BE mode?
The booting log show as following:
call sys_access(/init)
Freeing unused kernel memory: 2832K (c0600000 - c08c4000)
kernel_init: try to execute '/init' (ramdisk_execute_command)
en->run_init_process(/init)
init (1): undefined instruction: pc=0000aab8
Code: f00f dff8 2a20 1268 (acec) 108b
Kernel panic - not syncing: Attempted to kill init! exitcode=0x00000004
The disassembly code show the undefined instruction is “vstmia”.
armeb-linux-gnueabihf-objdump -D busybox_unstripped > busy.asm
0000aa90 <__sigsetjmp>:
...
aab6: 6812 ldr r2, [r2, #0] aab8: ecac 8b10 vstmia ip!, {d8-d15} aabc: f412 7f00 tst.w r2, #512 ; 0x200The rootfs is busybox 1.22.1 compiled by Linaro BE hard floating toolchain.
https://releases.linaro.org/14.04/components/toolchain/binaries/gcc-linaro-a...
The instruction is valid and encoded correctly as far as I can tell. I would suspect that this exception may be related to the kernel VFP handling code.