rpi-cmdline, rpi-u-boot-src: Support USB boot

The Raspberry Pi 4 board can boot the image from USB memory. But current meta-raspberrypi supports only SD boot. This commit allows switching SD boot to other device. For example, if you want to use USB boot, please define the following parameters in your conf/local.conf file. CMDLINE_ROOT_PARTITION = "/dev/sda2" BOOT_MEDIA = "usb" v3: Changed variable name to "BOOT_MEDIA" (was "BOOT_DEVTIPE"). v2: Set existing microSD parameter as default. User can overwrite some parameters. Signed-off-by: Harunobu Kurokawa <[email protected]>
agherzan · Aug 20, 2023 · fedae88 · fedae88
1 parent 8e07f0d
commit fedae88
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Showing 4 changed files with 22 additions and 3 deletions.
diff --git a/docs/extra-build-config.md b/docs/extra-build-config.md
@@ -74,6 +74,20 @@ To remove (or adjust) this delay set these variables in local.conf:
     BOOT_DELAY = "0"
     BOOT_DELAY_MS = "0"
 
+## Boot media
+
+The Raspberry Pi 4 board can load the boot image files from SD card and USB memory.
+By default SD card media is used as boot media.
+
+To switch the boot media from SD card the following variables are supported
+in local.conf: `CMDLINE_ROOT_PARTITION` and `BOOT_MEDIA`.
+
+For example, if you want to use USB boot, please define
+the following parameters in your local.conf file.
+
+    CMDLINE_ROOT_PARTITION = "/dev/sda2"
+    BOOT_MEDIA = "usb"
+
 ## Set overclocking options
 
 The Raspberry Pi can be overclocked. As of now overclocking up to the "Turbo

diff --git a/recipes-bsp/bootfiles/rpi-cmdline.bb b/recipes-bsp/bootfiles/rpi-cmdline.bb
@@ -9,7 +9,9 @@ inherit deploy nopackages
 CMDLINE_DWC_OTG ?= "dwc_otg.lpm_enable=0"
 
 CMDLINE_ROOT_FSTYPE ?= "rootfstype=ext4"
-CMDLINE_ROOTFS ?= "root=/dev/mmcblk0p2 ${CMDLINE_ROOT_FSTYPE} rootwait"
+CMDLINE_ROOT_PARTITION ?= "/dev/mmcblk0p2"
+
+CMDLINE_ROOTFS ?= "root=${CMDLINE_ROOT_PARTITION} ${CMDLINE_ROOT_FSTYPE} rootwait"
 
 CMDLINE_SERIAL ?= "${@oe.utils.conditional("ENABLE_UART", "1", "console=serial0,115200", "", d)}"
 

diff --git a/recipes-bsp/rpi-u-boot-scr/files/boot.cmd.in b/recipes-bsp/rpi-u-boot-scr/files/boot.cmd.in
@@ -1,4 +1,4 @@
 fdt addr ${fdt_addr} && fdt get value bootargs /chosen bootargs
-fatload mmc 0:1 ${kernel_addr_r} @@KERNEL_IMAGETYPE@@
-if test ! -e mmc 0:1 uboot.env; then saveenv; fi;
+fatload @@BOOT_MEDIA@@ 0:1 ${kernel_addr_r} @@KERNEL_IMAGETYPE@@
+if test ! -e @@BOOT_MEDIA@@ 0:1 uboot.env; then saveenv; fi;
 @@KERNEL_BOOTCMD@@ ${kernel_addr_r} - ${fdt_addr}
diff --git a/recipes-bsp/rpi-u-boot-scr/rpi-u-boot-scr.bb b/recipes-bsp/rpi-u-boot-scr/rpi-u-boot-scr.bb
@@ -9,9 +9,12 @@ INHIBIT_DEFAULT_DEPS = "1"
 
 SRC_URI = "file://boot.cmd.in"
 
+BOOT_MEDIA ?= "mmc"
+
 do_compile() {
     sed -e 's/@@KERNEL_IMAGETYPE@@/${KERNEL_IMAGETYPE}/' \
         -e 's/@@KERNEL_BOOTCMD@@/${KERNEL_BOOTCMD}/' \
+        -e 's/@@BOOT_MEDIA@@/${BOOT_MEDIA}/' \
         "${WORKDIR}/boot.cmd.in" > "${WORKDIR}/boot.cmd"
     mkimage -A ${UBOOT_ARCH} -T script -C none -n "Boot script" -d "${WORKDIR}/boot.cmd" boot.scr
 }