In /logs/firmware/unblob_extracted/firmware_extract/4325012-58052244.squashfs_v4_le_extract/usr/sbin/rc.iverase line 4:

[ -f $functions ] && . $functions || {

                  ^-- SC2015 (info): Note that A && B || C is not if-then-else. C may run when A is true.

                       ^--------^ SC1090 (warning): ShellCheck can't follow non-constant source. Use a directive to specify location.

In /logs/firmware/unblob_extracted/firmware_extract/4325012-58052244.squashfs_v4_le_extract/usr/sbin/rc.iverase line 10:

	_cmd='_res=$(mount | grep "on[[:blank:]]\+$1[[:blank:]]") || _err=$?'

             ^-- SC2016 (info): Expressions don't expand in single quotes, use double quotes for that.

In /logs/firmware/unblob_extracted/firmware_extract/4325012-58052244.squashfs_v4_le_extract/usr/sbin/rc.iverase line 11:

	eval $_cmd

             ^---^ SC2086 (info): Double quote to prevent globbing and word splitting.

Did you mean: 

	eval "$_cmd"

In /logs/firmware/unblob_extracted/firmware_extract/4325012-58052244.squashfs_v4_le_extract/usr/sbin/rc.iverase line 12:

	if [ $_err -ne 0 ]; then

             ^---^ SC2154 (warning): _err is referenced but not assigned.

             ^---^ SC2086 (info): Double quote to prevent globbing and word splitting.

Did you mean: 

	if [ "$_err" -ne 0 ]; then

In /logs/firmware/unblob_extracted/firmware_extract/4325012-58052244.squashfs_v4_le_extract/usr/sbin/rc.iverase line 23:

printf "Erasing $IVDIR\n"

       ^----------------^ SC2059 (info): Don't use variables in the printf format string. Use printf '..%s..' "$foo".

For more information:

  https://www.shellcheck.net/wiki/SC1090 -- ShellCheck can't follow non-const...

  https://www.shellcheck.net/wiki/SC2154 -- _err is referenced but not assign...

  https://www.shellcheck.net/wiki/SC2015 -- Note that A && B || C is not if-t...