2008/5/16 Wolfgang Denk wd@denx.de:
In message cdb837ea0805152231w72340d28r4ee31ee5d4d51654@mail.gmail.com you wrote:
- Both default config of u-boot and a DHT-Walut-patched config
generate 256KB bin, but the flash on board is 512KB. So I think I should get a 512KB bin for flash writing.
Why?
Do you think on devices with 128 MB flash memory we should have a 128MB U-Boot image?
Do you see any problem with having a U-Boot image that is smaller than your flash device?
- The contents in the flash on my board is totally corrupted by
accident. It means the important last-4-bytes should be rewritten to a proper state.
Agreed.
- Currenly, I have to use special hardware to write bin into flash.
Therefore 256KB bin will only overwrite the first half. The last-4-bytes in the end of flash is still the old value.
That's your problem, tehn. Most people use a noremal JTAG debugger which can prgram the image to any address in the flash.
You got to add 256k of ramdom data in front of the 256 k image, then [memory filled with 0xFF recommended].
haha! Great minds seem alike. Actually, if no solution, I will try this method. Well. As you mentioned, using JTAG we can put bin in any place of flash. Does it means we should manually set the last-4-bytes? How to determine the exact entry point of bin? I can only see the hex value of last-4-bytes, and it definitely does not simply jump to the beginning of bin. It should jump to some location like "start:" in, for example, start.asm. Therefore the JTAG user should translate "jmp start+offset" to machine code by hand. Am I right?
Last, let me tell you why I cannot use JTAG. The recommend method by u-boot is using BDI2000. But it is really expensive. I don't have enough money. hehe. I have tried many home-made wiggler JTAG connectors with OCD commander, but all failed. Finally I give up for finding low-cost PPC JTAG. Currently I give the precompiled bin to some one with special flash writer, and let them burn.
Best regards, -- ShenLei