dualbrain/agon-flash

Agon MOS firmware upgrade utility

Agon MOS firmware upgrade utility

This utility comes in two versions:

1. A generic utility version needing at least MOS version 1.02 that will flash new versions of Agon MOS, . The utility is loaded as a MOS command and can take arguments from the commandline.
2. A 'legacy' utility version that can upgrade MOS 1.00 or 1.01 to MOS 1.02 only. Afterwards, the generic version can be used to upgrade to later MOS versions.

Generic version (Needs MOS firmware 1.02)

This version needs at least MOS version 1.02, which supports loadable commands with arguments.

Installation

1. Make sure to create a 'mos' directory on the microSD card
2. Place the flash.bin from in the 'mos' directory
3. Place the required firmware file in the root directory of the microSD card
4. Obtain the CRC32 checksum for the new firmware. The table below lists the checksums for common MOS versions. If you like to provide a checksum for your own MOS binary, some good tips are: The crc32 utility on Linux, or a website like https://simplycalc.com/crc32-file.php. For the latter, use the default polynomial of 04C11DB7, upload the firmware and note the result for use in the upgrade utility.

Usage

Usage: FLASH <filename> <crc32>

The provided CRC32 needs to be 4byte, with or without a leading 0x, in hexadecimal format.

Valid MOS CRC32 checksums

MOS version	Filename	CRC32
1.02	firmware102.bin	0xFE59E98D

Legacy version (MOS firmware 1.00/1.01)

This version can run on MOS version 1.00 or 1.01 and will do a single upgrade to MOS version 1.02

Installation

1. Place the flash_legacy.bin in the root directory of the microSD card
2. Place the firmware102.bin in the root directory of the microSD card

Usage

Load and Jump to the binary in memory:

LOAD flash_legacy.bin
JMP &040000

Workflow

The utility reads in the given firmware file to memory and verifies this against the given CRC32 checksum. If the file is larger than the amount of flash, the tool will exit. Upon checksum verification, the user is asked whether or not to proceed.

The utility then creates an image backup of the entire current flash area, stores that in memory and checksums it. The entire flash is unlocked and erased and the given firmware is programmed. Verification to the given CRC32 checksum is done on the flash. When this fails, the backup image is reprogrammed to the flash drive in similar fashion and verified to it's original CRC32 checksum.

The MOS currently has no built-in backup code, or second slot, that it can access from flash. If for whatever reason, the checksum of the new firmware should fail, the utility automatically tries to recover by reprogramming the backup code to the flash drive again. If that too fails, the only remaining option is to use a Zilog Programming cable and recover the firmware using it.

Disclaimer

Having subjected my own gear muuuuultiple times to this utility, I feel it's safe for general use in upgrading the MOS firmware to a new version. The responsibility for any issues during and/or after the firmware upgrade, lies with the user of this utility.