AWBoot

Small linux bootloader for Allwinner T113-s3, T113-s4, V851s

Building

Run make VARIANT=all LOG_LEVEL=40.
This builds every supported output (fel/spi/sdmmc/emmc) and produces awboot binaries with valid EGON headers.
VARIANT accepts a comma‑separated list (for example VARIANT=fel,emmc) if you only need a subset, and LOG_LEVEL continues to control verbosity (default 30 = info).

Using

You will need xfel for uploading the file to memory or SPI flash.
This it not needed for writing to an SD card.

FEL memory boot:

1. Build the variant that includes FEL (make VARIANT=fel …).
2. Provide your kernel/dtb (and optional initrd).
3. Run the helper script:

./tools/fel.sh path/to/zImage path/to/board.dtb [path/to/initrd]

The script uploads the freshly built awboot-fel.bin, kernel, DTB and optional initrd, updates the FEL mailboxes and boots the SoC automatically.

FEL SPI NOR boot:

make VARIANT=spi spi-boot.img
xfel spinor
xfel spinor write 0 spi-boot.img
xfel reset

FEL SPI NAND boot:

make VARIANT=spi spi-boot.img
xfel spi_nand
xfel spi_nand write 0 spi-boot.img
xfel reset

SD Card boot:

• create an MBR or GPT partition table and a FAT32 partition with an offset of 4MB or more using fdisk.

sudo fdisk /dev/(your sd device)

write awboot-boot.bin to sdcard with an offset of:

• MBR: 8KB (sector 16)
• GPT: 128KB (sector 256)

sudo dd if=awboot-boot-sd.bin of=/dev/(your sd device) bs=1024 seek=8

• compile (if needed) and copy your .dtb file to the FAT partition.
• copy zImage to the FAT partition.

Linux kernel:

WIP kernel from here: https://github.com/smaeul/linux/tree/d1/all