I'm from Mainland China and I'm using RAmos W7, which is also RK28 based.I successfully modified system.img and get it rooted, but when I tried to modify init.rk28board.rc, it failed to boot from the modified boot.img. I didn't use cramfsck and mkcramfs, for they don't support bootable partition.I used cramfsck to extract boot.img and modified nothing, then used mkcramfs to pack it, I found the new boot.img is different from the origin one.So I tried mkfs.cramfsI modified nothing, and the output boot.img is the same as the origin one.The only difference between them is that the origin one has a 4-byte CRC code at the end of the file, while the new build one has nothing there.I tried to burn the new boot.img, but my MID failed to boot again. If I add the 4-byte code to the new boot.img, it is just the same as the origin one and successfully boot the machine.If I add a randomly 4-byte code to make the new boot.img the same length as the old one, still cannot boot. So anyone can figure out how these 4 byte comes? They are different from CRC32 which mkfs.cramfs gives.This is my first post in slatedroid. For I'm not a native speaker, sorry for my English if my post is not easy to read.
mkdir bootfsmount -t cramfs -o loop boot.img bootfstar cvzf boot.tgz bootfstar xzvf boot.tgzmkfs.cramfs -n v1.01 bootfs boot.img