From 11bde902893847943ab4cf8340de1be849c716e5 Mon Sep 17 00:00:00 2001
From: SolidHal <hal@halemmerich.com>
Date: Tue, 15 Oct 2019 07:22:01 -0700
Subject: [PATCH] Add label based initramfs debugging

---
 DOCUMENTATION.md                        | 11 ++++++-----
 resources/BuildResources/initramfs-init | 11 ++++++++++-
 2 files changed, 16 insertions(+), 6 deletions(-)

diff --git a/DOCUMENTATION.md b/DOCUMENTATION.md
index 812c0f1..a1e724d 100644
--- a/DOCUMENTATION.md
+++ b/DOCUMENTATION.md
@@ -119,16 +119,17 @@ The initramfs is what runs initialy at boot, and allows us to enter a password a
 
 In a normal system, when dmcrypt/LUKS is setup the initramfs image is modified to enable decrypting of the root partiton
 
-Since we have to have a static initramfs image, and can't change it without recompiling the kernel, we have to be a little crafty to support unencrypted and encrypted root partitons with the same initramfs
+Since we have to have a static initramfs image, and can't change it without recompiling the kernel, we detect whether encryption is in use by checking for the tag `crypto_LUKS` on the root device at boot.
 
-This is achieved by placing flags in the /boot partition, aka `/dev/mmcblk2p2` or `/dev/sda2`. The /boot partiton is empty on an unencrypted system. When root encryption is set up, the file `root_encryption` is created, which the initramfs init script uses to determine that it should try and decrypt the root partiton 
 
 ### debugging the init script
-A rescue debug shell is entered when the init script encounters a problem, or if the `debug` flag is set
+A rescue debug shell is entered when the init script encounters a problem, or if a device with the partition label `RESCUESHELL` is present
 
-You can enable the debug flag by mounting /boot and creating a file named `debug`
+Label any partition on the system with `RESCUESHELL` to enter the initramfs rescue shell before mount and root_switch.
 
-To make the system boot normally, from the debug prompt, run `rm /boot/debug` and `exit` to reboot
+You can do this with `cgpt add -i 1 -l RESCUESHELL /dev/sda` for example to label the first partiton of a usb drive.
+
+This is the suggested method, as then debugging can be enabled/disabled by plugging in/removing the usb device. 
 
 
 
diff --git a/resources/BuildResources/initramfs-init b/resources/BuildResources/initramfs-init
index 6f8461e..5680eac 100644
--- a/resources/BuildResources/initramfs-init
+++ b/resources/BuildResources/initramfs-init
@@ -21,6 +21,8 @@ echo In PrawnOS Init
 
 #add this to start shell at desired point
 rescue_shell() {
+    [ "{$1}" != "debug" ] && echo "Something went wrong. Dropping to a shell." > /dev/tty1
+    [ "{$1}" == "debug" ] && echo "Debug flag detected, entering debug shell" > /dev/tty1
     echo "Something went wrong. Dropping to a shell." > /dev/tty1
     exec setsid /bin/sh -c 'exec /bin/sh </dev/tty1 >/dev/tty1 2>&1'
 }
@@ -64,6 +66,13 @@ echo ${ROOT_DEV} > /dev/tty1
 # the next boot stage
 CMDLINE='cat /proc/cmdline'
 
+# label any partition on the system with RESCUESHELL to enter the initramfs rescue shell before mount and root_switch.
+# you can do this with "cgpt add -i 1 -l RESCUESHELL /dev/sda" for example to label the first partiton of a usb drive.
+if [ -n "$(blkid | grep RESCUESHELL)" ]
+then
+    rescue_shell debug
+fi
+
 if [ -n "$(blkid ${ROOT_DEV}2 | grep crypto_LUKS)" ]
 then
     #decrypt and mount the root filesystem
@@ -79,5 +88,5 @@ fi
 umount /sys
 umount /proc
 
-#swith to the new rootfs
+#switch to the new rootfs
 exec switch_root /newroot /sbin/init ${CMDLINE}