[U-Boot-Users] debug u-boot using bdi2000

I'm trying to use bdi2000+gdb to debug u-boot. The image is ROM image on flash, whenever I connect gdb to bdi, I saw execution stops at:

_start: /* time t 0 */ li r21, BOOTFLAG_COLD /* Normal Power-On: Boot from FLASH*/ ===>here nop b boot_cold

Then though I can set break point, e.g. cpu_init_f, but when continue running break point never stops execution and u-boot just runs by itself.

Does it mean I can only debug ram image? does anyone has experience on this could shed some lights?

Thanks.

- Reeve