labs: yocto: beagleplay: lab1: add a patch to enable uboot env saving

This is not enabled by default on the Beagleplay. Actually, CMD_SAVEENV
is defined but we only have ENV_IS_NOWHERE set so U-boot disables
saveenv. So this patch does the following:

- Set CONFIG_ENV_IS_IN_FAT and related variables.
- Unset CONFIG_ENV_IS_NOWHERE so that when U-boot fails to read the
  file uboot.env on initial boot (the file is not present yet), it
  doesn't fail to "save to nowhere" and save the env to uboot.env
  instead.

Signed-off-by: Antonin Godard <[email protected]>

lab-data/yocto-beagleplay/bootlin-lab-data/0004-u-boot-enable-saving-the-env-in-fat-partition.patch

@@ -0,0 +1,48 @@
+From ec95a0130c23f498ef08f7226512ce596ecec604 Mon Sep 17 00:00:00 2001
+From: Antonin Godard <[email protected]>
+Date: Wed, 13 Nov 2024 13:48:41 +0100
+Subject: [PATCH] u-boot: enable saving the env in fat partition
+
+This is not enabled by default on the Beagleplay. Actually, CMD_SAVEENV
+is defined but we only have ENV_IS_NOWHERE set so U-boot disables
+saveenv. So this patch does the following:
+
+- Set CONFIG_ENV_IS_IN_FAT and related variables.
+- Unset CONFIG_ENV_IS_NOWHERE so that when U-boot fails to read the
+  file uboot.env on initial boot (the file is not present yet), it
+  doesn't fail to "save to nowhere" and save the env to uboot.env
+  instead.
+
+Signed-off-by: Antonin Godard <[email protected]>
+---
+ .../recipes-bsp/u-boot/u-boot-ti-staging/env-in-fat.cfg    | 7 +++++++
+ .../recipes-bsp/u-boot/u-boot-ti-staging_2024.04.bb        | 2 ++
+ 2 files changed, 9 insertions(+)
+ create mode 100644 meta-ti-bsp/recipes-bsp/u-boot/u-boot-ti-staging/env-in-fat.cfg
+
+diff --git a/meta-ti-bsp/recipes-bsp/u-boot/u-boot-ti-staging/env-in-fat.cfg b/meta-ti-bsp/recipes-bsp/u-boot/u-boot-ti-staging/env-in-fat.cfg
+new file mode 100644
+index 00000000..a22b7db6
+--- /dev/null
++++ b/meta-ti-bsp/recipes-bsp/u-boot/u-boot-ti-staging/env-in-fat.cfg
+@@ -0,0 +1,7 @@
++CONFIG_ENV_IS_IN_FAT=y
++CONFIG_ENV_FAT_INTERFACE="mmc"
++CONFIG_ENV_FAT_DEVICE_AND_PART="1:1"
++CONFIG_ENV_FAT_FILE="uboot.env"
++CONFIG_SYS_MMC_ENV_DEV=0
++CONFIG_SYS_MMC_ENV_PART=0
++# CONFIG_ENV_IS_NOWHERE is not set
+diff --git a/meta-ti-bsp/recipes-bsp/u-boot/u-boot-ti-staging_2024.04.bb b/meta-ti-bsp/recipes-bsp/u-boot/u-boot-ti-staging_2024.04.bb
+index e3e86b30..1740aa8b 100644
+--- a/meta-ti-bsp/recipes-bsp/u-boot/u-boot-ti-staging_2024.04.bb
++++ b/meta-ti-bsp/recipes-bsp/u-boot/u-boot-ti-staging_2024.04.bb
+@@ -7,3 +7,5 @@ PR = "r0"
+ BRANCH = "ti-u-boot-2024.04"
+
+ SRCREV = "cdac8b4cd3cc1d1e9ac6354c1cfe03ddbbdf01fa"
++
++SRC_URI += "file://env-in-fat.cfg"
+-- 
+2.46.1
+

labs/yocto-first-build-beagleplay/yocto-first-build-beagleplay.tex

@@ -49,7 +49,8 @@ \section{Download Yocto}
 git checkout -b scarthgap-labs 10.01.03
 git am $HOME/__SESSION_NAME__-labs/bootlin-lab-data/0001-Simplify-linux-ti-staging-recipe-for-the-Bootlin-lab.patch \
   $HOME/__SESSION_NAME__-labs/bootlin-lab-data/0002-Don-t-use-a-custom-deployment-directory.patch \
-  $HOME/__SESSION_NAME__-labs/bootlin-lab-data/0003-Use-extlinux.conf-booting-flow.patch
+  $HOME/__SESSION_NAME__-labs/bootlin-lab-data/0003-Use-extlinux.conf-booting-flow.patch \
+  $HOME/__SESSION_NAME__-labs/bootlin-lab-data/0004-u-boot-enable-saving-the-env-in-fat-partition.patch
 \end{bashinput}
 
 \section{Set up the build environment}