updater rescue_shell busybox install
cbrake opened this issue · 4 comments
cbrake commented
we have the following code in the updater:
rescue_shell() {
msg "$@"
msg "Something went wrong. Dropping you to a shell."
busybox --install -s
exec /bin/sh
}When the shell is launched, we get:
Something went wrong. Dropping you to a shell.
--install: applet not found
/bin/sh: can't access tty; job control turned off
~ #
~ #
@kraj do you recall what the busybox --install is for?
kraj commented
This does install operation on busybox and -s makes symlinks see [1]
fact that --install fails to execute, means that we have to enable this in defconfig for busybox.
maybe we need to add CONFIG_INSTALL=y to defconfig. Alternatively we can delete it completely too
[1] https://git.busybox.net/busybox/tree/INSTALL?h=1_34_stable#n104
cbrake commented
here is the info on that:
Installing links to busybox is not always necessary. The special applet name
"busybox" (or with any optional suffix, such as "busybox-static") uses the
first argument to determine which applet to behave as, for example
"./busybox cat LICENSE". (Running the busybox applet with no arguments gives
a list of all enabled applets.) The standalone shell can also call busybox
applets without links to busybox under other names in the filesystem. You can
also configure a standalone install capability into the busybox base applet,
and then install such links at runtime with one of "busybox --install" (for
hardlinks) or "busybox --install -s" (for symlinks).
I'm seeing this in the initramfs (below is sampling, there is a lot more):
lrwxrwxrwx 1 root root 23 Mar 9 2018 sort -> /usr/bin/busybox.nosuid
lrwxrwxrwx 1 root root 23 Mar 9 2018 ssl_client -> /usr/bin/busybox.nosuid
lrwxrwxrwx 1 root root 23 Mar 9 2018 stat -> /usr/bin/busybox.nosuid
lrwxrwxrwx 1 root root 23 Mar 9 2018 strings -> /usr/bin/busybox.nosuid
lrwxrwxrwx 1 root root 23 Mar 9 2018 stty -> /usr/bin/busybox.nosuid
lrwxrwxrwx 1 root root 21 Mar 9 2018 su -> /usr/bin/busybox.suid
lrwxrwxrwx 1 root root 23 Mar 9 2018 svc -> /usr/bin/busybox.nosuid
lrwxrwxrwx 1 root root 23 Mar 9 2018 svok -> /usr/bin/busybox.nosuid
lrwxrwxrwx 1 root root 23 Mar 9 2018 sync -> /usr/bin/busybox.nosuid
lrwxrwxrwx 1 root root 23 Mar 9 2018 tail -> /usr/bin/busybox.nosuid
lrwxrwxrwx 1 root root 23 Mar 9 2018 tar -> /usr/bin/busybox.nosuid
lrwxrwxrwx 1 root root 23 Mar 9 2018 tee -> /usr/bin/busybox.nosuid
lrwxrwxrwx 1 root root 23 Mar 9 2018 telnet -> /usr/bin/busybox.nosuid
lrwxrwxrwx 1 root root 23 Mar 9 2018 test -> /usr/bin/busybox.nosuid
lrwxrwxrwx 1 root root 23 Mar 9 2018 tftp -> /usr/bin/busybox.nosuid
lrwxrwxrwx 1 root root 23 Mar 9 2018 time -> /usr/bin/busybox.nosuid
lrwxrwxrwx 1 root root 23 Mar 9 2018 timeout -> /usr/bin/busybox.nosuid
lrwxrwxrwx 1 root root 23 Mar 9 2018 top -> /usr/bin/busybox.nosuid
lrwxrwxrwx 1 root root 23 Mar 9 2018 touch -> /usr/bin/busybox.nosuid
lrwxrwxrwx 1 root root 23 Mar 9 2018 tr -> /usr/bin/busybox.nosuid
lrwxrwxrwx 1 root root 21 Mar 9 2018 traceroute -> /usr/bin/busybox.suid
lrwxrwxrwx 1 root root 23 Mar 9 2018 tree -> /usr/bin/busybox.nosuid
lrwxrwxrwx 1 root root 23 Mar 9 2018 true -> /usr/bin/busybox.nosuid
lrwxrwxrwx 1 root root 23 Mar 9 2018 ts -> /usr/bin/busybox.nosuid
lrwxrwxrwx 1 root root 23 Mar 9 2018 tsort -> /usr/bin/busybox.nosuid
lrwxrwxrwx 1 root root 23 Mar 9 2018 tty -> /usr/bin/busybox.nosuid
lrwxrwxrwx 1 root root 23 Mar 9 2018 umount -> /usr/bin/busybox.nosuid
lrwxrwxrwx 1 root root 23 Mar 9 2018 uname -> /usr/bin/busybox.nosuid
lrwxrwxrwx 1 root root 23 Mar 9 2018 uniq -> /usr/bin/busybox.nosuid
lrwxrwxrwx 1 root root 23 Mar 9 2018 unlink -> /usr/bin/busybox.nosuid
lrwxrwxrwx 1 root root 23 Mar 9 2018 unshare -> /usr/bin/busybox.nosuid
lrwxrwxrwx 1 root root 23 Mar 9 2018 unzip -> /usr/bin/busybox.nosuid
-rwxr-xr-x 1 root root 4679 Mar 9 2018 update-alternatives
lrwxrwxrwx 1 root root 23 Mar 9 2018 uptime -> /usr/bin/busybox.nosuid
Can we assume that Yocto has already set up all the links and we don't need to run busybox --install or is there something more that this does?
kraj commented
yeah I would think so. In this case we can just remove the busybox --install -s cmd.