conf: machine: imx8m[m,n,p]: enable extlinux support

Newer U-Boot versions enables distro boot option as a default. This
requires that the target uses either Syslinux or boot script in order to
start instead of customized boot environment.

Since according to U-Boot documentation [1], Syslinux is considered as a
preferred way of using distro boot - enable it for imx8mm, imx8mn and
imx8mp derivatives for mainline BSP.

Syslinux options are introduced in machine-specific headers in order
to assemble correct extlinux.conf file.

Signed-off-by: Andrey Zhizhikin <andrey.z@gmail.com>
Link: [1]: https://source.denx.de/u-boot/u-boot/-/blob/master/doc/README.distro

1 files changed, 19 insertions, 0 deletions

diff --git a/conf/machine/include/imx8mn-evk.inc b/conf/machine/include/imx8mn-evk.inc
index 6a5b31f7..a0e39857 100644
--- a/conf/machine/include/imx8mn-evk.inc
+++ b/conf/machine/include/imx8mn-evk.inc
@@ -46,6 +46,25 @@ IMX_BOOT_SOC_TARGET = "iMX8MN"
 
 SERIAL_CONSOLES = "115200;ttymxc1"
 
+# Add support for Syslinux to mainline BSP.
+# U-Boot has the Distro Boot mode enabled by default, which
+# require that either Syslinux to be enabled, or a boot script
+# to be used to define the boot process.
+# We opt-in for Syslinux, since it is designated as a preferred
+# distro boot mode according to the U-Boot documentation.
+UBOOT_EXTLINUX_use-mainline-bsp = "1"
+UBOOT_EXTLINUX_LABELS_use-mainline-bsp = "default"
+UBOOT_EXTLINUX_DEFAULT_LABEL_use-mainline-bsp = "i.MX8M Nano EVK"
+
+UBOOT_EXTLINUX_MENU_DESCRIPTION_default_use-mainline-bsp = "i.MX8M Nano EVK"
+UBOOT_EXTLINUX_FDT_default_use-mainline-bsp     = "../${KERNEL_DEVICETREE_BASENAME}.dtb"
+UBOOT_EXTLINUX_CONSOLE_default_use-mainline-bsp = "console=${console}"
+UBOOT_EXTLINUX_ROOT_default_use-mainline-bsp    = "root=/dev/mmcblk1p2"
+
+# Add extlinux.conf to the lis of files, which are deployed onto the
+# boot partition
+IMAGE_BOOT_FILES_append_use-mainline-bsp = " extlinux.conf;extlinux/extlinux.conf"
+
 BOOT_SPACE = "65536"
 LOADADDR = ""
 UBOOT_SUFFIX = "bin"