Hey all,
I just found that lib_arm/board.c:start_armboot()'s GCC3.4.0 generated code sequence breaks ARM u-boot's. I am using the GCC3.4.0 which CodeSourcery put out.
I have found what appears to be a fix. A compiler optimization barrier needs to be inserted after gd (AKA R8) is initialized. See the below snippit.
With out this barrier gd is calculated into a temporary register, and when the gd->bd is actually attempted an unitilized R8 is used causing a fatal abort.
Regards,
Richard W.
------------------------------------- void start_armboot (void) { DECLARE_GLOBAL_DATA_PTR;
ulong size; init_fnc_t **init_fnc_ptr; char *s; #if defined(CONFIG_VFD) unsigned long addr; #endif
/* Pointer is writable since we allocated a register for it */ gd = (gd_t*)(_armboot_start - CFG_MALLOC_LEN - sizeof(gd_t));
__asm__ __volatile__("": : :"memory");/* compiler please write out gd to R8 now before using again */
memset ((void*)gd, 0, sizeof (gd_t)); gd->bd = (bd_t*)((char*)gd - sizeof(bd_t)); memset (gd->bd, 0, sizeof (bd_t));