C64Mini FEL-mode hack - no UART needed Jan 8, 2020 7:41:15 GMT
Post by jj0 on Jan 8, 2020 7:41:15 GMT
The kernel image in nanda is an Android Boot image which itself is a combination of a config file, the kernel (as zImage) and the initrd.img boot ramdisk. You can manipulate this image by using for example the abootimg tools in Ubuntu. The nanda is (highly likely) the same for all Maxi's so making it available isn't really necessary, though it might help someone who has bricked his Maxi.
uImage: u-boot legacy uImage, Linux-3.4.39, Linux/ARM, OS Kernel Image (Not compressed), 11276000 bytes, Sun Jan 6 10:35:00 2019, Load Address: 0x40008000, Entry Point: 0x40008000, Header CRC: 0x41C26174, Data CRC: 0xAF1D42B9Or would the loader understand both, since the boot.sh script seems to upload an u-boot as well, so it could support both formats perhaps? (see, I'm a novice at this...)
nanda: Android bootimg, kernel (0x40008000), ramdisk (0x41000000), page size: 2048
For FEL-booting the Maxi you can use the nanda image but you still need an u-boot-sunxi-with-spl (which initialises the system and then loads and runs the kernel) that is compiled for the H3 SoC and that has support for Android images enabled.
You can also extract the image (abootimg-unpack-initrd), make changes to the initrd.img and repack (abootimg-pack-initrd) it again and then create a new boot image to use with FEL or even to replace the original nanda with. The nice thing about this is that if you e.g. want to load some custom modules they would be in the ramdisk which is discarded after boot so the changes would not take up space on the Maxi's nandb rootfs. You can of course also compile your own kernel from the various Allwinner SDK's that are available for similar H3 boards.
There is a lot of information about the boot process, u-boot, kernel compiling, FEL booting for Allwinner SoC's on the sunxi wiki.