Booting AST2600 using UART5 debug mode

The AST2600 has a recovery mode where it can boot a payload from the UART. This must be enabled by a strapping pin.

If you haven’t set up a development machine these tools will get you close:

sudo apt install gcc-arm-linux-gnueabi make u-boot-tools git minicom

Build u-boot and SPL

git clone -b v2019.04-aspeed-openbmc
cd u-boot
ARCH=ARM CROSS_COMPILE=arm-linux-gnueabi- make ast2600_openbmc_spl_defconfig
ARCH=ARM CROSS_COMPILE=arm-linux-gnueabi- make -j8

Prepare the images

tools/ spl/u-boot-spl.bin u-boot-spl-recovery.bin
mkimage -A arm -O u-boot -C none -a 0x83000000 -e 0x83000000 -d u-boot.bin u-boot-recovery.bin

Prepare system

Power off your system. Set the “Boot from UART” strap. Power it back on.

minicom -D /dev/ttyUSB0 -b 115200

Load recovery SPL

cat u-boot-spl-recovery.bin > /dev/ttyUSB0

You will see:


U-Boot SPL 2019.04-05549-g08e425111892 (Apr 24 2020 - 13:17:07 +0930)
Trying to boot from UART

Send u-boot with minicom

ctrl+a s in minicom to send a file with ymodem. When complete it will jump to u-boot proper.

CCC - CRC mode, 4345(SOH)/0(STX)/0(CAN) packets, 6 retries
Loaded 555824 bytes

U-Boot 2019.04-05549-g08e425111892 (Apr 24 2020 - 13:32:52 +0930)

SOC: AST2600-A1

From there you will be in a u-boot environment which can be used to recover the system.

Written on April 24, 2020