Dear Minkyu Kang,
Am 11.01.2011 11:57, schrieb Minkyu Kang:
Regardless of the patch, if your code writes to panel_info or any other BSS variable before relocation it will trash the relocation tables that exist at BSS location at this point.
IOW, accessing BSS before relocation is forbidden, not just out of fancy, but for a serious reason.
This patch is not for accessing BSS before relocation, it's for prevent exceptions.
The real error is writing to BSS before relocation. This leads to a corrupted .rel.dyn section which is placed at the same address as .bss at this moment (bss is overloaded to save space).
If you look in your ELF (e.g. readelf -R .rel.dyn u-boot) you may see, that the .rel.dyn section does _not_ include a pointer to 0x0 with relative relocation (0x17) as you showed in a previous post. If you look in your u-boot.map you may find the function in question (test_func() was it in your example) is placed in .bss section. Setting the function pointer to 0 (e.g. test_func() = NULL, as described in previous mail) before relocation will destroy your .rel.dyn section and then you will see a zero in .rel.dyn section at some place ... please investigate the ELF and do not step through the code to find those issues.
I may be wrong, please show it to us.
regards
Andreas Bießmann