Apply user UART baudrate setting to permanent UART port on dual-UART boards

[FelixvdDonk]

Problem

On hardware with two UART ports (e.g. Flipsky 75100, 75100_V2, and many others), the permanent UART port (UART_PORT_BUILTIN) ignores the user-configured baudrate setting (app_uart_baudrate). It is always stuck at the hardcoded HW_UART_P_BAUD value (typically 115200), regardless of what the user sets in VESC Tool.

Root cause

In app_set_configuration(), the configure call for the permanent UART passed 0 as the baudrate:

app_uartcomm_configure(0, appconf.permanent_uart_enabled, UART_PORT_BUILTIN);

Since app_uartcomm_configure() skips baudrate updates when the value is 0, the permanent port was locked to its hardware default forever.

Fix

Pass appconf.app_uart_baudrate to the permanent UART — but only when the board's HW_UART_P_BAUD matches the default APPCONF_UART_BAUDRATE (115200). This ensures boards that intentionally set a non-standard permanent baud for dedicated peripherals (e.g. Unity at 250000 for BLE, A200S V4 at 1000000 for logger) are not affected.

app_uartcomm_configure(
    (HW_UART_P_BAUD == APPCONF_UART_BAUDRATE) ? appconf.app_uart_baudrate : 0,
    appconf.permanent_uart_enabled, UART_PORT_BUILTIN);

Impact

• Boards with HW_UART_P_BAUD == 115200 (~45 boards): permanent UART now respects user baudrate setting. No behavioral change unless the user explicitly changes the baudrate.
• Boards with custom HW_UART_P_BAUD (Unity, A200S V4/V4.1): zero change in behavior.
• Affected hardware includes: Flipsky 75100, 75100_V2, FSESC 75_300, 75_200_ALU, MakerBase 75_100, Trampa 60/HD, and all other dual-UART boards using the default 115200 permanent baud.> app_uartcomm_configure(0, appconf.permanent_uart_enabled, UART_PORT_BUILTIN);

Since `app_uartcomm_configure()` skips baudrate updates when the value is `0`, the permanent port was locked to its hardware default forever.

**Fix**

Pass `appconf.app_uart_baudrate` to the permanent UART — but only when the board's `HW_UART_P_BAUD` matches the default `APPCONF_UART_BAUDRATE` (115200). This ensures boards that intentionally set a non-standard permanent baud for dedicated peripherals (e.g. Unity at 250000 for BLE, A200S V4 at 1000000 for logger) are not affected.

```c
app_uartcomm_configure(
    (HW_UART_P_BAUD == APPCONF_UART_BAUDRATE) ? appconf.app_uart_baudrate : 0,
    appconf.permanent_uart_enabled, UART_PORT_BUILTIN);

Impact

• Boards with HW_UART_P_BAUD == 115200 (~45 boards): permanent UART now respects user baudrate setting. No behavioral change unless the user explicitly changes the baudrate.
• Boards with custom HW_UART_P_BAUD (Unity, A200S V4/V4.1): zero change in behavior.
• Affected hardware includes: Flipsky 75100, 75100_V2, FSESC 75_300, 75_200_ALU, MakerBase 75_100, Trampa 60/HD, and all other dual-UART boards using the default 115200 permanent baud.

[FelixvdDonk]

I'm not too familiar with the way the secondary uart is configured and how costly it is on the MCU. I'm in the position where i need the second port of the Flipsky 75100 to go to a higher baudrate (1500000 baud) but I can't do it currently in the vesc tool