soc: rp2040: Added UF2 output file support

Added support for the UF2 file format for the RP2040 SoC

Signed-off-by: Yonatan Schachter <yonatan.schachter@gmail.com>

Kconfig.zephyr

@@ -462,6 +462,7 @@ config BUILD_OUTPUT_UF2_FAMILY_ID
 	default "0xada52840" if SOC_NRF52840_QIAA
 	default "0x4fb2d5bd" if SOC_SERIES_IMX_RT
 	default "0x2abc77ec" if SOC_SERIES_LPC55XXX
+	default "0xe48bff56" if SOC_SERIES_RP2XXX
 	default "0x68ed2b88" if SOC_SERIES_SAMD21
 	default "0x55114460" if SOC_SERIES_SAMD51
 	default "0x647824b6" if SOC_SERIES_STM32F0X

boards/arm/rpi_pico/doc/index.rst

@@ -83,6 +83,15 @@ command (assuming JLink is used):
 
    $ openocd -f interface/jlink.cfg -c 'transport select swd' -f target/rp2040.cfg -c "adapter speed 2000" -c 'targets rp2040.core0' -c 'program path/to/zephyr.elf verify reset exit'
 
+Using UF2
+---------
+
+If you don't have an SWD adapter, you can flash the Raspberry Pi Pico with
+a UF2 file. By default, building an app for this board will generate a
+`build/zephyr/zephyr.uf2` file. If the Pico is powered on with the `BOOTSEL`
+button pressed, it will appear on the host as a mass storage device. The
+UF2 file should be drag-and-dropped to the device, which will flash the Pico.
+
 Debugging
 =========
 

boards/arm/rpi_pico/rpi_pico_defconfig

@@ -6,3 +6,4 @@ CONFIG_CONSOLE=y
 CONFIG_UART_CONSOLE=y
 CONFIG_GPIO=y
 CONFIG_USE_DT_CODE_PARTITION=y
+CONFIG_BUILD_OUTPUT_UF2=y

soc/arm/rpi_pico/rp2/Kconfig.defconfig.rp2040

@@ -6,3 +6,9 @@
 config SOC
 	default "rp2040"
 	depends on SOC_RP2040
+
+config BUILD_OUTPUT_UF2_USE_FLASH_BASE
+	default y if RP2_REQUIRES_SECOND_STAGE_BOOT
+
+config BUILD_OUTPUT_UF2_USE_FLASH_OFFSET
+	default y if !RP2_REQUIRES_SECOND_STAGE_BOOT