In /logs/firmware/unblob_extracted/firmware_extract/4325012-58052244.squashfs_v4_le_extract/usr/libexec/pre-parhand-set-defaults line 3:

. /lib/rcscripts/sh/error.sh

  ^------------------------^ SC1091 (info): Not following: /lib/rcscripts/sh/error.sh was not specified as input (see shellcheck -x).

In /logs/firmware/unblob_extracted/firmware_extract/4325012-58052244.squashfs_v4_le_extract/usr/libexec/pre-parhand-set-defaults line 5:

. $conffile || error "Failed to source '$conffile'!"

  ^-------^ 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/libexec/pre-parhand-set-defaults line 11:

	parameters=`bootblocktool -l |grep '^root\.'`

                   ^-- SC2006 (style): Use $(...) notation instead of legacy backticks `...`.

Did you mean: 

	parameters=$(bootblocktool -l |grep '^root\.')

In /logs/firmware/unblob_extracted/firmware_extract/4325012-58052244.squashfs_v4_le_extract/usr/libexec/pre-parhand-set-defaults line 29:

		value=`echo "${param#*=}" | sed 's!/!\\/!g'`

                      ^-- SC2006 (style): Use $(...) notation instead of legacy backticks `...`.

Did you mean: 

		value=$(echo "${param#*=}" | sed 's!/!\\/!g')

In /logs/firmware/unblob_extracted/firmware_extract/4325012-58052244.squashfs_v4_le_extract/usr/libexec/pre-parhand-set-defaults line 36:

			printf "$configuration" > "$tempfile" || warning "Failed to update value in $brand_conf"

                               ^--------------^ 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/SC1091 -- Not following: /lib/rcscripts/sh/...

  https://www.shellcheck.net/wiki/SC2059 -- Don't use variables in the printf...