TS-4300 Baseboard Support
In the selected boot method u-boot loads a device tree which describes the hardware the kernel runs on. The imx93-ts4300.dtb is always loaded to describe the TS-4300 hardware. Every baseboard is supported using a device tree overlay.
This extends the TS-4300 device tree with the features needed to support the carrier board. In u-boot, this is loaded using u-boot's extension support.
All of our off the shelf baseboards contain a hard-wired 8-input multiplexer to indicate the baseboard model. This is not required to implement in custom baseboards, but it can be useful to identify the board model in software. The u-boot extension will scan the baseboard id, eg, the TS-8551 which is hard wired as 0x16.
- S0 is connected to CN2_006
- S1 is connected to CN2_008
- S2 is connected to CN1_098
- BD_ID_DATA is connected to CN1_083
The 6 least significant input pins (Y0 - Y5) are used to define the baseboard model. The upper two inputs (Y6 and Y7) define board revision.
The baseboard id is specified in hex, so the TS-8551 searches for:
imx93-ts4300-16.dtbo
If it exists, it is applied automatically with "extension apply all" in our standard boot scripts. Custom carrier boards should use the ID "0x2a", which will never be used by our off the shelf boards.