heads/initrd/init
Jonathon Hall 4b58788063
init: Execute /bin/sh for interactive shell, not /bin/bash
bash will not be the default interactive shell since readline support
increases the binary size significantly.  Use /bin/sh (busybox ash) for
that.

Signed-off-by: Jonathon Hall <jonathon.hall@puri.sm>
2023-03-08 12:45:53 -05:00

181 lines
5.0 KiB
Bash
Executable File

#!/bin/bash
mknod /dev/ttyprintk c 5 3
echo "hello world" > /dev/ttyprintk
# Setup our path
export PATH=/sbin:/bin:/usr/sbin:/usr/bin:/usr/local/bin
# This is the very first script invoked by the Linux kernel and is
# running out of the ram disk. There are no fileysstems mounted.
# It is important to have a way to invoke a recovery shell in case
# the boot scripts are messed up, but also important to modify the
# PCRs if this happens to prevent the TPM disk keys from being revealed.
# First thing it is vital to mount the /dev and other system directories
mkdir /proc /sys /dev /tmp /boot /media 2>&- 1>&-
mount /dev 2>/dev/ttyprintk
mount /proc 2>/dev/ttyprintk
mount /sys 2>/dev/ttyprintk
mount /sys/kernel/security 2>/dev/ttyprintk
if [ "$CONFIG_LINUXBOOT" = "y" ]; then
mount /sys/firmware/efi/efivars
fi
# Setup the pty psudeo filesystem
mkdir /dev/pts
mount /dev/pts 2>/dev/ttyprintk
if [ ! -r /dev/ptmx ]; then
ln -s /dev/pts/ptmx /dev/ptmx
fi
# Needed by bash
if ! [ -L /bin/bash ]; then
# /bin/bash is not a symbolink link (not busybox)
[ -a /dev/stdin ] || ln -s /proc/self/fd/0 /dev/stdin
[ -a /dev/stdout ] || ln -s /proc/self/fd/1 /dev/stdout
[ -a /dev/stderr ] || ln -s /proc/self/fd/2 /dev/stderr
[ -a /dev/fd ] || ln -s /proc/self/fd /dev/fd
fi
# Recovery shells will erase anything from here
mkdir -p /tmp/secret
# Now it is safe to print a banner
if [ -r /etc/motd ]; then
cat /etc/motd > /dev/tty0
fi
# Load the date from the hardware clock, setting it in local time
hwclock -l -s
# Read the system configuration parameters
. /etc/functions
. /etc/config
TRACE "Under init"
# set CONFIG_TPM dynamically before init
if [ ! -e /dev/tpm0 ]; then
CONFIG_TPM='n'
CONFIG_TPM2_TOOLS='n'
warn 'No TPM found...'
fi
#Specify whiptail background colors cues under FBWhiptail only
if [ -x /bin/fbwhiptail ]; then
export BG_COLOR_WARNING="${CONFIG_WARNING_BG_COLOR:-"--background-gradient 0 0 0 150 125 0"}"
export BG_COLOR_ERROR="${CONFIG_ERROR_BG_COLOR:-"--background-gradient 0 0 0 150 0 0"}"
else
export BG_COLOR_WARNING="${CONFIG_WARNING_BG_COLOR:-""}"
export BG_COLOR_ERROR="${CONFIG_ERROR_BG_COLOR:-""}"
fi
if [ "$CONFIG_TPM2_TOOLS" = "y" ]; then
# Initialize tpm2 encrypted sessions here
tpmr startsession
fi
if [ "$CONFIG_COREBOOT" = "y" ]; then
/bin/cbfs-init
fi
if [ "$CONFIG_LINUXBOOT" = "y" ]; then
/bin/uefi-init
fi
# Set GPG_TTY before calling gpg in key-init
export GPG_TTY=/dev/console
/bin/key-init
# Setup recovery serial shell
if [ ! -z "$CONFIG_BOOT_RECOVERY_SERIAL" ]; then
stty -F "$CONFIG_BOOT_RECOVERY_SERIAL" 115200
pause_recovery 'Console recovery shell' \
< "$CONFIG_BOOT_RECOVERY_SERIAL" \
> "$CONFIG_BOOT_RECOVERY_SERIAL" 2>&1 &
fi
# load USB modules for boards using a USB keyboard
if [ "$CONFIG_USB_KEYBOARD" = "y" ]; then
enable_usb
fi
# If the user has been holding down r, enter a recovery shell
# otherwise immediately start the configured boot script.
# We don't print a prompt, since this is a near instant timeout.
read \
-t 0.1 \
-n 1 \
boot_option
echo
if [ "$boot_option" = "r" ]; then
# Start an interactive shell
recovery 'User requested recovery shell'
# just in case...
if [ "$CONFIG_TPM" = "y" ]; then
tpmr extend -ix 4 -ic recovery
fi
exec /bin/sh
exit
fi
# Override CONFIG_TPM and CONFIG_TPM2_TOOLS from /etc/config with runtime value
# determined above.
#
# Values in user config have higher priority during combining thus effectively
# changing the value for the rest of the scripts which source /tmp/config.
echo "export CONFIG_TPM=\"$CONFIG_TPM\"" >> /etc/config.user
echo "export CONFIG_TPM2_TOOLS=\"$CONFIG_TPM2_TOOLS\"" >> /etc/config.user
combine_configs
. /tmp/config
# export firmware version
export FW_VER=$(dmesg | grep 'DMI' | grep -o 'BIOS.*' | cut -f2- -d ' ')
# chop off date, since will always be epoch w/timeless builds
FW_VER=${FW_VER::-10}
# Add our boot devices into the /etc/fstab, if they are defined
# in the configuration file.
if [ ! -z "$CONFIG_BOOT_DEV" ]; then
echo >> /etc/fstab "$CONFIG_BOOT_DEV /boot auto defaults,ro 0 0"
fi
if [ ! -x "$CONFIG_BOOTSCRIPT" -a ! -x "$CONFIG_BOOTSCRIPT_NETWORK" ]; then
recovery 'Boot script missing? Entering recovery shell'
else
if [ -x "$CONFIG_BOOTSCRIPT_NETWORK" ]; then
echo '***** Network Boot:' $CONFIG_BOOTSCRIPT_NETWORK
$CONFIG_BOOTSCRIPT_NETWORK
echo '***** Network Boot Completed:' $CONFIG_BOOTSCRIPT_NETWORK
# not blocking
fi
if [ -x "$CONFIG_BOOTSCRIPT" ]; then
echo '***** Normal boot:' $CONFIG_BOOTSCRIPT
if [ -x /bin/setsid ] && [ -x /bin/agetty ]; then
for console in $CONFIG_BOOT_EXTRA_TTYS; do
setsid agetty -aroot -l"$CONFIG_BOOTSCRIPT" "$console" linux &
done
fi
exec "$CONFIG_BOOTSCRIPT"
# We should never reach here, but just in case...
recovery 'Boot script failure? Entering recovery shell'
else
# wait for boot via network to occur
pause_recovery 'Override network boot. Entering recovery shell'
fi
fi
# belts and suspenders, just in case...
if [ "$CONFIG_TPM" = "y" ]; then
tpmr extend -ix 4 -ic recovery
fi
exec /bin/sh