[U-Boot] Uboot on qemu vexpress-a9 flash question?

Leo Wang leointic at hotmail.com
Wed Jun 28 23:20:44 UTC 2017


Hello experts

I am new to u-boot. I am trying to use qemu-arm to run u-boot. After reading online materials, my question is that if it is possible to save the environment variables on simulated Flash "permanently". I use raw file "pflash0.img" as simulated flash. So far, after modify some #defines in the header file, now I can run the following:

" qemu-system-arm -M vexpress-a9 -kernel u-boot -m 512M -nographic -drive file=pflash0.img,format=raw,if=pflash  "

u-boot boots ok, and I can save the env variables. It takes effects after "reset" u-boot. However, the values does not get written into the flash image file. So next time I run qemu using same "pflash0.img"
file. The environment variables get lost. you will have "bad CRC" message again.

I have these two questions:

1. Is it possible to save the environment variables to qemu simulated flash file "permanently"?

2. u-boot seems only report the flash size that links to config header files and does not link to the qemu simulated flash image size, that is to say no matter how big or small I created the ""pflash0.img" file, uboot only reports 128MiB flash.

Maybe I am doing something very stupid here. Please anybody can give some suggestions.

Thank you all!

--
Yonghao (Leo) Wang


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