commit 138b5d8022c7800161807b60995084218477951e
author Jim Ostrowski <yimmy13@gmail.com> Sat Feb 26 01:01:45 2022 -0800
committer Jim Ostrowski <yimmy13@gmail.com> Wed Mar 02 00:08:02 2022 -0800
tree 3fec92b4db55a358a27b9c230a755a69cd61c659
parent 296710bc088979541bccefe8ddde98c926dd32dc

Update build instructions and handle image filename better

Allow user to call function twice, and detect modified image filename
Updated image creation instructions to include IMU adis16505.ko

Change-Id: I33d0323b21ec1d4e2db26537149a5b2cdc091a60
Signed-off-by: Jim Ostrowski <yimmy13@gmail.com>

frc971/raspi/rootfs/README.md

diff --git a/frc971/raspi/rootfs/README.md b/frc971/raspi/rootfs/README.md
index b972038..a349eb5 100644
--- a/frc971/raspi/rootfs/README.md
+++ b/frc971/raspi/rootfs/README.md
@@ -10,7 +10,7 @@
 ## Build the real-time kernel using `build_kernel.sh`
 
 - Checkout the real-time kernel source code, e.g.,
-  `cd CODE_DIR`
+  `cd CODE_DIR`, where CODE_DIR is the directory containing the FRC971 code
   `git clone git@github.com:frc971/linux.git`
   `git checkout frc971-5.10-pi4-rt branch`
 
@@ -18,6 +18,13 @@
   `cd ROOTFS_DIR` (where ROOTFS_DIR -> //frc971/raspi/rootfs)
   `./build_kernel.sh CODE_DIR/linux kernel_5.10.tar.gz`
 
+## Build the ADIS16505 overlay file (adis16505.ko)
+
+- Make sure the linux kernel source code is checked out at CODE_DIR/linux
+- cd //y2022/localizer/kernel
+- `make`
+- copy that file to this directory (//frc971/raspi/rootfs)
+
 ## Download the Raspberry Pi OS
 
 Download the appropriate Raspberry Pi OS image, e.g.,

frc971/raspi/rootfs/modify_rootfs.sh

diff --git a/frc971/raspi/rootfs/modify_rootfs.sh b/frc971/raspi/rootfs/modify_rootfs.sh
index 15bdd80..c3582ea 100755
--- a/frc971/raspi/rootfs/modify_rootfs.sh
+++ b/frc971/raspi/rootfs/modify_rootfs.sh
@@ -4,6 +4,19 @@
 
 # Full path to Raspberry Pi Bullseye disk image
 IMAGE="2022-01-28-raspios-bullseye-arm64-lite.img"
+MOD_IMAGE_NAME=`echo ${IMAGE} | sed s/.img/-frc-mods.img/`
+
+if [ ! -f "$IMAGE" ]; then
+    echo "Attempting to use already modified image"
+    if [ ! -f "$MOD_IMAGE_NAME" ]; then
+        echo "Must provide image filename."
+        echo "Couldn't find $IMAGE or $MOD_IMAGE_NAME"
+        exit 1
+    fi
+    echo "Using already modified image: ${MOD_IMAGE_NAME}"
+    IMAGE=$MOD_IMAGE_NAME
+fi
+
 # Kernel built with build_kernel.sh
 KERNEL="kernel_5.10.tar.gz"
 BOOT_PARTITION="${IMAGE}.boot_partition"
@@ -116,6 +129,7 @@
 # Add a file to show when this image was last modified and by whom
 TIMESTAMP_FILE="${PARTITION}/home/pi/.ImageModifiedDate.txt"
 echo "Date modified:"`date` > "${TIMESTAMP_FILE}"
+echo "Image file: ${IMAGE}"  >> "${TIMESTAMP_FILE}"
 echo "Git tag: "`git rev-parse HEAD` >> "${TIMESTAMP_FILE}"
 echo "User: "`whoami` >> "${TIMESTAMP_FILE}"
 
@@ -125,6 +139,7 @@
 sudo umount -l "${PARTITION}"
 rmdir "${PARTITION}"
 
-# Move the image to a different name, to indicated we've modified it
-MOD_IMAGE_NAME=`echo ${IMAGE} | sed s/.img/-frc-mods.img/`
-mv ${IMAGE} ${MOD_IMAGE_NAME}
+# Move the image to a different name, to indicate we've modified it
+if [ ${IMAGE} != ${MOD_IMAGE_NAME} ]; then
+  mv ${IMAGE} ${MOD_IMAGE_NAME}
+fi