Initial commit

inshim.sh

@@ -0,0 +1,7 @@
+#!/bin/bash
+mount /dev/sda1 /mnt/stateful_partition
+if [ "$(id -u)" -ne 0 ]
+then
+    echo "Run this as root"
+fi
+cp /usr/share/packeddata/. /mnt/stateful_partition/unencrypted -rvf

modify.sh

@@ -0,0 +1,61 @@
+#!/bin/bash
+
+
+make_block_device_rw() {
+  local block_dev="$1"
+  [[ -b "${block_dev}" ]] || return 0
+  if [[ $(sudo blockdev --getro "${block_dev}") == "1" ]]; then
+    sudo blockdev --setrw "${block_dev}"
+  fi
+}
+is_ext2_rw_mount_enabled() {
+  local rootfs=$1
+  local offset="${2-0}"
+  local ro_compat_offset=$((0x464 + 3))  # Get 'highest' byte
+  local ro_compat_flag=$(sudo dd if="${rootfs}" \
+    skip=$((offset + ro_compat_offset)) bs=1 count=1  status=none \
+    2>/dev/null | hexdump -e '1 "%.2x"')
+  test "${ro_compat_flag}" = "00"
+}
+
+# Returns whether the passed rootfs is an extended filesystem by checking the
+# ext2 s_magic field in the superblock.
+is_ext_filesystem() {
+  local rootfs=$1
+  local offset="${2-0}"
+  local ext_magic_offset=$((0x400 + 56))
+  local ext_magic=$(sudo dd if="${rootfs}" \
+    skip=$((offset + ext_magic_offset)) bs=1 count=2 2>/dev/null |
+    hexdump -e '1/2 "%.4x"')
+  test "${ext_magic}" = "ef53"
+}
+enable_rw_mount() {
+  local rootfs=$1
+  local offset="${2-0}"
+  local ro_compat_offset=$((0x464 + 3))  # Set 'highest' byte
+  is_ext_filesystem "${rootfs}" "${offset}" || return 0
+  is_ext2_rw_mount_enabled "${rootfs}" "${offset}" && return 0
+
+  make_block_device_rw "${rootfs}"
+  printf '\000' |
+    sudo dd of="${rootfs}" seek=$((offset + ro_compat_offset)) \
+      conv=notrunc count=1 bs=1 status=none
+  # Force all of the file writes to complete, in case it's necessary for
+  # crbug.com/954188
+  sync
+}
+
+usage() {
+    echo "Usage: <Shim file>"
+}
+if [ "$(id -u)" -ne 0 ]
+then
+    echo "Run as root"
+    exit 0
+fi
+if [ $# -lt 1 ]
+then
+    usage
+    exit 0
+fi
+