Use at your own risk!
Coded for the following PCIe devices:
- https://axxon.io/lf781kb_pcie_8s_rs232_adapter/
- https://axxon.io/lf729kb_16s_rs232_pcie_adapter_card/
They identify as a "PCI Express-to-PCI Bridge" ("PEX 8112") and two or four instances of a "OX16PCI954" PCI device (each providing four UART interfaces).
On some cards not all "OX16PCI954" are properly flashed, which might result in output like this:
$ lspci
65:00.0 PCI bridge: PLX Technology, Inc. PEX8112 x1 Lane PCI Express-to-PCI Bridge (rev aa)
66:00.0 Serial controller: Oxford Semiconductor Ltd OX16PCI954 (Quad 16950 UART) function 0 (Uart)
66:00.1 Bridge: Oxford Semiconductor Ltd OX16PCI954 (Quad 16950 UART) function 0 (Disabled)
66:01.0 Serial controller: Oxford Semiconductor Ltd OX16PCI954 (Quad 16950 UART) function 0 (Uart)
66:01.1 Bridge: Oxford Semiconductor Ltd OX16PCI954 (Quad 16950 UART) function 1 (8bit bus)
66:02.0 Serial controller: Oxford Semiconductor Ltd OX16PCI954 (Quad 16950 UART) function 0 (Uart)
66:02.1 Bridge: Oxford Semiconductor Ltd OX16PCI954 (Quad 16950 UART) function 1 (8bit bus)
66:03.0 Serial controller: Oxford Semiconductor Ltd OX16PCI954 (Quad 16950 UART) function 0 (Uart)
66:03.1 Bridge: Oxford Semiconductor Ltd OX16PCI954 (Quad 16950 UART) function 1 (8bit bus)
Notice how all but the first "slot" have a second function with "8bit bus" - and linux even tries to use them as 4xUART with the "serial" driver...
You'll need cargo from rust to build the tool.
To build (if outdated / not compiled yet) and run:
cargo run --bin axxon-ox16pci954-flash
To pass options to the program, insert -- before them:
cargo run --bin axxon-ox16pci954-flash -- --help
To actually flash the contained images (instead of just checking them) use:
cargo run --bin axxon-ox16pci954-flash -- --flash
Before flashing the tool makes sure that the "PEX 8112" bridge contains axxon in the image at the
required place, and that "OX16PCI954" devices are on a bus behind such bridges.
The chip supports various modes via two functions, which could be configured via two pins (although there isn't a "good" way to only enable 4x UART on function 0 and disable function 1).
Only function 0 (4x UART) is of interest, function 1 is not wired.
Uses an (optional, but present on the Axxon cards) external EEPROM for configuration; the EEPROM data is a word (16-bit) stream.
The flashing tool from the vendor disables function 1 by writing 0x00 to the lower 8-bit of the
device id, effectively making it 1415:9500 (which is the official ID for "disabled function 0",
not "disabled function 1", which would be 1415:9510).
This is the PCIe-to-PCI bridge, and identifies as a device with a single function (PCI id
10b5:8112).
Documentation ("Data Book") was available from: https://www.broadcom.com/products/pcie-switches-bridges/pcie-bridges/pex8112#documentation
Uses an (optional, but present on the Axxon cards) external EEPROM for configuration; the EEPROM
data is a byte stream. At offset 0x78 (120) the data should contain the string axxon (although
the PCI device won't care about that).