Re: [U-Boot] [PATCH 1/4] mpc83xx: Make start.S true PIC

Dear Joakim Tjernlund,

In message 1292838435-14958-1-git-send-email-Joakim.Tjernlund@transmode.se you wrote:

Remove dependencies on link address. Use GOT and add an new function to calculate the actual address.

Signed-off-by: Joakim Tjernlund Joakim.Tjernlund@transmode.se

arch/powerpc/cpu/mpc83xx/start.S | 35 +++++++++++++++++++++++++++-------- 1 files changed, 27 insertions(+), 8 deletions(-)

It seems this code introduces some subtle changes.

• lis r4, (CONFIG_SYS_MONITOR_BASE)@h
• ori r4, r4, (CONFIG_SYS_MONITOR_BASE)@l
• addi r5, r4, in_flash - _start + EXC_OFF_SYS_RESET
• mtlr r5

The original code references CONFIG_SYS_MONITOR_BASE.

• bl add_flash_base

...

+add_flash_base:

• /* Check if already inside flash address space. */
• /* if so, do not add CONFIG_SYS_FLASH_BASE */
• lis r4, (CONFIG_SYS_FLASH_BASE)@h
• ori r4, r4, (CONFIG_SYS_FLASH_BASE)@l
• cmplw cr0, r3, r4
• ble cr0, 2f /* r3 < r4 ? */
• lis r6, (CONFIG_SYS_FLASH_BASE+(CONFIG_SYS_FLASH_SIZE*1024*1024-1))@h
• ori r6, r6, (CONFIG_SYS_FLASH_BASE+(CONFIG_SYS_FLASH_SIZE*1024*1024-1))@l
• cmplw cr0, r3, r6
• blelr cr0 /* r3 < r6 ? */

+2: add r3,r3,r4

• blr

But your new code does not reference CONFIG_SYS_MONITOR_BASE at all, but uses CONFIG_SYS_FLASH_BASE instead.

On which boards has this been tested?

Best regards,

Wolfgang Denk