imx-base.inc: Expand comment for UBOOT_SUFFIX

The UBOOT_SUFFIX override is complex and makes a requirement on the
machine config that is easy to overlook, namely that it will
evaluate incorrectly to empty if the variable is not overridden
in some form by the machine config.

Signed-off-by: Tom Hochstein <tom.hochstein@nxp.com>

1 files changed, 8 insertions, 0 deletions

diff --git a/conf/machine/include/imx-base.inc b/conf/machine/include/imx-base.inc
index f14d782e..37991f39 100644
--- a/conf/machine/include/imx-base.inc
+++ b/conf/machine/include/imx-base.inc
@@ -60,6 +60,14 @@ UBOOT_BINARY ?= "u-boot.${UBOOT_SUFFIX}"
 # |
 # | UBOOT_MACHINE = "mx53loco_config"
 # `----
+#
+# Please note that UBOOT_SUFFIX must be set in the machine config even
+# if the value is the same for the U-Boot flavors. If the value is not
+# set, then the assignment here is the one used, the value resolves to
+# empty, and the build fails:
+# | cp: cannot stat '/.../tmp/work/imx8qm_mek-fsl-linux/u-boot-imx/2022.04-r0/build/imx8qm_mek_defconfig/u-boot.': No such file or directory
+#| WARNING: /.../tmp/work/imx8qm_mek-fsl-linux/u-boot-imx/2022.04-r0/temp/run.do_compile.21223:186 exit 1 from 'cp /.../tmp/work/imx8qm_mek-fsl-linux/u-boot-imx/2022.04-r0/build/${config}/${binary} /.../tmp/work/imx8qm_mek-fsl-linux/u-boot-imx/2022.04-r0/build/${config}/u-boot-${type}.${UBOOT_SUFFIX:pn-u-boot-imx}'
+#
 IMX_DEFAULT_BOOTLOADER ??= "u-boot-fslc"
 UBOOT_SUFFIX ?= "${UBOOT_SUFFIX:pn-${IMX_DEFAULT_BOOTLOADER}}"