I would like to use the return of the command 'gpio input' in an if statement in U-Boot but it doesn't seem to work.
So I've tried something like :
if test {gpio status 50} -eq 1; then echo 1; else echo 0; fi;
But it always return 1 whether the GPIO is high or low.
I also tried to store the result of the gpio status command into a variable by using the setenv command but it doesn't work either.
PS: I've modified the gpio.c file in the U-boot source code so the command returns just '0' or '1' instead of 'gpio: pin 50 (gpio 50) value is 1' but I think it doesn't matter. Just precising since otherwise the '-eq 1' makes no sense.
Do you have any idea of how I could proceed to do this ?
Thanks in advance !
The return value of a command can be found in environment variable $?, e.g.
gpio input 50; echo $?
If an if statement exists, depends on the configuration when compiling U-Boot. Use CONFIG_HUSH_PARSER=y to enable it. When enabled you can write
if gpio input 102; then setenv board_name revA ; else setenv board_name revB;fi
Related
I came from this article: https://blog.quarkslab.com/defeating-ebpf-uprobe-monitoring.html and this worked well for me:
# First log-in as root.
# This line creates a uretprobe named bashReadline at offset 0xd5690 of /bin/bash program that prints the return value as a string.
echo 'r:bashReadline /bin/bash:0xd5690 cmd=+0($retval):string' >> /sys/kernel/tracing/uprobe_events
# When the uprobe is added, activate it with this command:
echo 1 > /sys/kernel/tracing/events/uprobes/bashReadline/enable
The interesting part is that I can use a static offset and no need to worry about ASLR. Why is that?
I am trying to create a TPM-based unlock script using tpm2-tools with instructions from Tevora Secure boot tpm2. I have set up the key, loaded it with cryptsetup luksAddKey secret.bin, then tested it using tpm2_unlock -c 0x81000000 --auth pci:sha1:0,2,3,7 and returns the value of secret.bin. For extra measures, to make sure it works, I loaded secret.bin into "/etc/crypttab", ran # update-initramfs -u -k all, and rebooted. Upon reboot, the system unlocked.
I copied over the following code into "/etc/initramfs-tools/hooks/tpm2"
#!/bin/sh -e
if [ "$1" = "prereqs" ]; then exit 0; fi
. /usr/share/initramfs-tools/hook-functions
copy_exec /usr/local/bin/tpm2_unseal
copy_exec /usr/local/lib/libtss2-tcti-device.so
I appended my etc/crypttab from cryptname UUID=xxxxxxxx-xxxx-xxxx-xxxx-xxxxxxxxxxxx none luks to cryptname UUID=xxxxxxxx-xxxx-xxxx-xxxx-xxxxxxxxxxxx none luks,keyscript=/usr/local/bin/passphrase-from-tpm
I rewrote the following script because the tpm2-tools command was outdated, edited in the new command, and stored it in /usr/local/bin/passphrase-from-tpm:
#!/bin/sh
set -e
echo "Unlocking via TPM" >&2
export TPM2TOOLS_TCTI="device:/dev/tpm0"
/usr/local/bin/tpm2_unseal -c 0x81000000 --auth pcr:sha1:0,2,3,7
if [ $? -eq 0 ]; then
exit
fi
/lib/cryptsetup/askpass "Unlocking the disk fallback $CRYPTTAB_SOURCE ($CRYPTTAB_NAME)\nEnter passphrase: "
I ran # update-initramfs -u -k all then rebooted. In reboot, I get the following error: /lib/cryptsetup/scripts/passphrase-from-tpm: line 5: /usr/local/bin/tpm2_unseal: not found
I have tried many times to edit passphrase-from-tpm unsuccessfully, including:
Moving both passphrase-from-tpm into "/boot/efi/EFI/BOOT/" and referencing crypttab to that file
Modifying passphrase-from-tpm to use a relative file path to tpm_unseal
Before I figured out how to create a backup linux boot using:
objcopy \
--add-section .osrel=/etc/os-release --change-section-vma .osrel=0x20000 \
--add-section .cmdline=cmdline.txt --change-section-vma .cmdline=0x30000 \
--add-section .linux="/boot/vmlinuz" --change-section-vma .linux=0x40000 \
--add-section .initrd="/boot/initrd.img" --change-section-vma .initrd=0x3000000 \
/usr/lib/systemd/boot/efi/linuxx64.efi.stub /boot/EFI/BOOT/BOOT_RECX64.EFI
I would be locked out of the system completely because of the error and had to reinstall Ubuntu about 40 times. I have suffered a lot and want to quit but I am too stubborn to throw in the flag.
just copy tpm2_unseal to /usr/local/bin/
I'm trying to make a working setup following basically those instructions, plus a few others I have found. While not working 100% yet, check that both /etc/initramfs-tools/hooks/tpm2 and /usr/local/bin/passphrase-from-tpm are marked executable (sudo chmod ug+x $filename).
After making the initramfs, you can run the following to ensure that the TPM related files are actually in the image. Replace the path in the filename by whatever update-initramfs said it was generating:
$ lsinitramfs /boot/initrd.img-5.0.0-37-generic | egrep "(tpm|libtss)"
lib/cryptsetup/scripts/passphrase-from-tpm
lib/modules/5.0.0-37-generic/kernel/crypto/asymmetric_keys/tpm_key_parser.ko
lib/modules/5.0.0-37-generic/kernel/crypto/asymmetric_keys/asym_tpm.ko
lib/udev/rules.d/tpm-udev.rules
usr/local/lib/libtss2-sys.so.0
usr/local/lib/libtss2-mu.so.0
usr/local/lib/libtss2-sys.so.0.0.0
usr/local/lib/libtss2-tcti-device.so
usr/local/lib/libtss2-tcti-device.so.0
usr/local/lib/libtss2-tcti-device.so.0.0.0
usr/local/lib/libtss2-mu.so.0.0.0
usr/local/bin/tpm2_unseal
Additionally, I have modified /usr/local/bin/passphrase-from-tpm to the following:
#!/bin/sh
TPM_DEVICE=/dev/tpm0
TPM_REGISTER=0x81000001
TPM_SEAL_POLICY=sha256:0,2,4,7
export TPM2TOOLS_TCTI="device:$TPM_DEVICE"
if [ "$CRYPTTAB_TRIED" -eq 0 ]; then
echo "Unlocking via TPM" >&2
/usr/local/bin/tpm2_unseal -H $TPM_REGISTER -L $TPM_SEAL_POLICY
UNSEAL_STATUS=$?
echo "Unseal status $UNSEAL_STATUS" >&2
if [ $UNSEAL_STATUS -eq 0 ]; then
exit
fi
else
echo "TPM unlocking previously failed for $CRYPTTAB_SOURCE ($CRYPTTAB_NAME)" >&2
/lib/cryptsetup/askpass "Enter passphrase for $CRYPTTAB_SOURCE ($CRYPTTAB_NAME): "
fi
Note that the command line options to tpm2_unseal are for the 3.x versions of tpm2-tools. If you're using another version, you might need to update the options.
I pulled out various bits into variables at the top of the file. Modify TPM_REGISTER and TPM_SEAL_POLICY to match how you created the TPM object. set -e was removed since if any command failed, the whole script would exit, preventing the askpass fallback from ever running if tpm2_unseal failed.
Additionally, I noticed that if the script fails for some reason, systemd will attempt to run it again. If the secret in the TPM doesn't match the LUKS key, this will render the system unbootable, since the unseal succeeds, but unlocking fails, and systemd will run the script again.
Looking at the man page for crypttab, I discovered that one of the environment variables provided to the keyscript is CRYPTTAB_TRIED which is the number of tries it has attempted to unlock the volume. If CRYPTTAB_TRIED is 0, it'll attempt to use the TPM, as shown by this test (Running as non-root, so accessing the TPM device fails):
$ export CRYPTTAB_SOURCE=some_device
$ export CRYPTTAB_NAME=some_device_name
$ export CRYPTTAB_TRIED=0
$ ./passphrase-from-tpm
Unlocking via TPM
ERROR:tcti:src/tss2-tcti/tcti-device.c:440:Tss2_Tcti_Device_Init() Failed to open device file /dev/tpm0: Permission denied
ERROR: tcti init allocation routine failed for library: "device" options: "/dev/tpm0"
ERROR: Could not load tcti, got: "device"
Unseal status 1
When it tries running the script again, CRYPTTAB_TRIED will be greater than 0, making it display the password prompt instead:
$ export CRYPTTAB_TRIED=1
$ ./passphrase-from-tpm
TPM unlocking previously failed for some_device (some_device_name)
Enter passphrase for some_device (some_device_name):
Hopefully this is still of use to you, and helpful to anyone else trying to get the house of cards that is disk encryption with a TPM on Linux working.
I have connected 2 raspberry pi using GPIO :
The first one is the master, and use GPIO2 (and GND...)
The second one is a slave, and use GPIO0 and GPIO1
All are switch on a relay card
I put GPIO1 and GPIO0 on direction "IN" and GPI02 on direction "out" :
echo in > /sys/class/gpio/gpioXX/direction
On my master, (GPIO2, direction = OUT), when i put the pin GPIO2 to 1, the 2 pins on my slave turn to 1 too. So, no probleme here
I add a shell script, using inotifywait on one folder (for example /sys/class/gpio/gpio18/ (18 for GPIO1)).
When I'm on my SLAVE, and i try to modify the value of /sys/class/gpio/gpio18/ with an echo 1 > .../value , inotifywait catch a modification, but the value didn't change ( -bash: echo: write error: Operation not permitted , it's normal because direction is on "IN" ).
When I'm on my MASTER, and i modify the value of gpio27 (corresponding to GPI02), both value file (GPIO0, GPIO1 and GPIO2) change, but my inotifywait didn't catch the modification on gpio/gpio18/value (the containt of the file change from 0 to 1 or inversely)
I can't say for sure what is wrong. But I would try running a simple script like this and see what happens:
while inotifywait -e modify /sys/class/gpio/gpio18/; do echo "Hello"; done
I saw a similar question here
After reading the answers and comment in the above link I located the 'libmwi18n.so' file and set the LD_LIBRRY_PATH, but I'm still getting this error:
'error while loading shared libraries: libmwi18n.so: cannot
open shared object file: No such file or directory'
I did the following:
locate libmwil8n.so
which gives output
/usr/local/MATLAB/R2012a/bin/glnx86/libmwi18n.so
Then I did
export LD_LIBRARY_PATH= /usr/local/MATLAB/R2012a/bin/glnx86
and ran the shell program again,
./run_app.sh
which returns the same error.
Please help me , how can I solve this problem?
Update-
content of the run_spp.sh
!/bin/sh
# script for execution of deployed applications
#
# Sets up the MCR environment for the current $ARCH and executes
# the specified command.
#
exe_name=$0
exe_dir=`dirname "$0"`
echo "------------------------------------------"
if [ "x$1" = "x" ]; then
echo Usage:
echo $0 \<deployedMCRroot\> args
else
echo Setting up environment variables
MCRROOT="$1"
echo ---
LD_LIBRARY_PATH=.:${MCRROOT}/runtime/glnx86 ;
LD_LIBRARY_PATH=${LD_LIBRARY_PATH}:${MCRROOT}/bin/glnx86 ;
LD_LIBRARY_PATH=${LD_LIBRARY_PATH}:${MCRROOT}/sys/os/glnx86;
MCRJRE=${MCRROOT}/sys/java/jre/glnx86/jre/lib/i386 ;
LD_LIBRARY_PATH=${LD_LIBRARY_PATH}:${MCRJRE}/native_threads ;
LD_LIBRARY_PATH=${LD_LIBRARY_PATH}:${MCRJRE}/server ;
LD_LIBRARY_PATH=${LD_LIBRARY_PATH}:${MCRJRE}/client ;
LD_LIBRARY_PATH=${LD_LIBRARY_PATH}:${MCRJRE} ;
XAPPLRESDIR=${MCRROOT}/X11/app-defaults ;
export LD_LIBRARY_PATH;
export XAPPLRESDIR;
echo LD_LIBRARY_PATH is ${LD_LIBRARY_PATH};
shift 1
args=
while [ $# -gt 0 ]; do
token=`echo "$1" | sed 's/ /\\\\ /g'` # Add blackslash before each blank
args="${args} ${token}"
shift
done
"${exe_dir}"/b $args
fi
exit
Your LD_LIBRARY_PATH should not include the library itself, but rather, the path that contains the library. Try:
export LD_LIBRARY_PATH=/usr/local/MATLAB/R2012a/bin/glnx86
or perhaps appending this location to the path:
export LD_LIBRARY_PATH=${LD_LIBRARY_PATH}:/usr/local/MATLAB/R2012a/bin/glnx86
EDIT: (after more info on question provided)
The shell script run_app.sh sets up it's own library path, using the environment variable LD_LIBRARY_PATH (it is declared in lines 17--24, and overwritten in line 26). This means that anything that is set in your shell before executing the script will be overwritten.
To include the path for libmwi18n.so, append the path within the script, after line 17 and before line 26, with:
LD_LIBRARY_PATH=${LD_LIBRARY_PATH}:/usr/local/MATLAB/R2012a/bin/glnx86
(Note: there is also a printout of the LD path so you should be able to tell whether the glnx86 path is present or not).
I think you want glnx86, not glnx68.
Apologies if that was just a typo in your question.
root#test:~# svcs serviceName
STATE STIME FMRI
disabled 21:29:14 svc:/application/serviceName:default
root#test:~# echo $?
0
I want to get the status of serviceName by the return value of command line. But svcs return 0 either the service is up or down.
How can I get it?
Thank you.
A command return value is meant to report if the command run successfully or not. Moreover, there are more states for a service than "up" or "down".
Nevertheless, you can achieve what you want with this shell (ksh & bash) function
function svc_up
{
[[ "$(svcs -Ho state $1)" == online ]]
}