how to debug the kernel when it stops at kernel booting?

[jlu]

I've a custom designed i.mx25 board. the board has nothing except a CAN, 2G NAND, 64MB DDR2, UART, some buttons, a clone to the 3 stack board for what it has. One PCB loads the kernel all right, another PCB, which is the 2nd layout and supposely better one, stops after "decompressing... done. booting kernel". I tried all kinds of kernel configuration in order to trace down where the problem comes from, but none gives me more info. among the configurations I've tried, "low-level debug functions" had caused periodic reset, "debug shared IRQ handlers" and "detect soft lockups" had caused unrecognisable bad data crc image file.

how can i trace down the problem?

[jlu]

I had hoped there would be some help from Freescale if nobody elese could answer a question. Clearly this is not the case.

Any how I would like to share my pregress.

If configuring through the linux configuration menu, turning on Low Level Debug will cause compiling error. This is there is no switch for this in debug.s (under kernel) without selecting ICE debug, which I don't have. My solution to this is hard code the definition of MXC_LL_UART_PADDR and MXC_LL_UART_VADDR to files asking for it. By this I got debug information until MMU is enabled.

My problem is now the kernel hangs after MMU is enabled and before booting information comes out. Anybody can give me some clues? Any comments will be much appreciated.