In /logs/firmware/unblob_extracted/firmware_extract/4325012-58052244.squashfs_v4_le_extract/usr/libexec/rtp-setup line 7:
. /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/rtp-setup line 12:
[ "$RTP_GROUPS" ] && [ $RTP_GROUPS -gt 0 ] ||
                  ^-- SC2015 (info): Note that A && B || C is not if-then-else. C may run when A is true.
                       ^---------^ SC2086 (info): Double quote to prevent globbing and word splitting.

Did you mean: 
[ "$RTP_GROUPS" ] && [ "$RTP_GROUPS" -gt 0 ] ||


In /logs/firmware/unblob_extracted/firmware_extract/4325012-58052244.squashfs_v4_le_extract/usr/libexec/rtp-setup line 22:
	[ $# -eq 1 ] && [ "$1" ] ||
                     ^-- SC2015 (info): Note that A && B || C is not if-then-else. C may run when A is true.


In /logs/firmware/unblob_extracted/firmware_extract/4325012-58052244.squashfs_v4_le_extract/usr/libexec/rtp-setup line 25:
	local array i=0 elem
        ^------------------^ SC3043 (warning): In POSIX sh, 'local' is undefined.


In /logs/firmware/unblob_extracted/firmware_extract/4325012-58052244.squashfs_v4_le_extract/usr/libexec/rtp-setup line 28:
	local start0=239 start1=192 range1 start2=0 range2 start3=0 range3
        ^-- SC3043 (warning): In POSIX sh, 'local' is undefined.


In /logs/firmware/unblob_extracted/firmware_extract/4325012-58052244.squashfs_v4_le_extract/usr/libexec/rtp-setup line 30:
	range1=$((251 - $start1 + 1))
                        ^-----^ SC2004 (style): $/${} is unnecessary on arithmetic variables.


In /logs/firmware/unblob_extracted/firmware_extract/4325012-58052244.squashfs_v4_le_extract/usr/libexec/rtp-setup line 31:
	range2=$((254 - $start2 + 1))
                        ^-----^ SC2004 (style): $/${} is unnecessary on arithmetic variables.


In /logs/firmware/unblob_extracted/firmware_extract/4325012-58052244.squashfs_v4_le_extract/usr/libexec/rtp-setup line 32:
	range3=$((255 - $start3 + 1))
                        ^-----^ SC2004 (style): $/${} is unnecessary on arithmetic variables.


In /logs/firmware/unblob_extracted/firmware_extract/4325012-58052244.squashfs_v4_le_extract/usr/libexec/rtp-setup line 47:
		[ -r /etc/conf.d/mac ] && . /etc/conf.d/mac && {
                                            ^-------------^ SC1091 (info): Not following: /etc/conf.d/mac was not specified as input (see shellcheck -x).


In /logs/firmware/unblob_extracted/firmware_extract/4325012-58052244.squashfs_v4_le_extract/usr/libexec/rtp-setup line 73:
				elem=$(($elem + $1 * $range1 / $RTP_GROUPS))
                                        ^---^ SC2004 (style): $/${} is unnecessary on arithmetic variables.
                                                     ^-----^ SC2004 (style): $/${} is unnecessary on arithmetic variables.
                                                               ^---------^ SC2004 (style): $/${} is unnecessary on arithmetic variables.


In /logs/firmware/unblob_extracted/firmware_extract/4325012-58052244.squashfs_v4_le_extract/usr/libexec/rtp-setup line 74:
				VIDEO_ADDR=$VIDEO_ADDR$(($start1 + $elem % $range1)).
                                                         ^-----^ SC2004 (style): $/${} is unnecessary on arithmetic variables.
                                                                   ^---^ SC2004 (style): $/${} is unnecessary on arithmetic variables.
                                                                           ^-----^ SC2004 (style): $/${} is unnecessary on arithmetic variables.


In /logs/firmware/unblob_extracted/firmware_extract/4325012-58052244.squashfs_v4_le_extract/usr/libexec/rtp-setup line 77:
				VIDEO_ADDR=$VIDEO_ADDR$(($start2 + $elem % $range2)).
                                                         ^-----^ SC2004 (style): $/${} is unnecessary on arithmetic variables.
                                                                   ^---^ SC2004 (style): $/${} is unnecessary on arithmetic variables.
                                                                           ^-----^ SC2004 (style): $/${} is unnecessary on arithmetic variables.


In /logs/firmware/unblob_extracted/firmware_extract/4325012-58052244.squashfs_v4_le_extract/usr/libexec/rtp-setup line 80:
				AUDIO_ADDR=$VIDEO_ADDR$(($start3 + ($elem + $range3 / 2) % $range3))
                                                         ^-----^ SC2004 (style): $/${} is unnecessary on arithmetic variables.
                                                                    ^---^ SC2004 (style): $/${} is unnecessary on arithmetic variables.
                                                                            ^-----^ SC2004 (style): $/${} is unnecessary on arithmetic variables.
                                                                                           ^-----^ SC2004 (style): $/${} is unnecessary on arithmetic variables.


In /logs/firmware/unblob_extracted/firmware_extract/4325012-58052244.squashfs_v4_le_extract/usr/libexec/rtp-setup line 81:
				VIDEO_ADDR=$VIDEO_ADDR$(($start3 + $elem % $range3))
                                                         ^-----^ SC2004 (style): $/${} is unnecessary on arithmetic variables.
                                                                   ^---^ SC2004 (style): $/${} is unnecessary on arithmetic variables.
                                                                           ^-----^ SC2004 (style): $/${} is unnecessary on arithmetic variables.


In /logs/firmware/unblob_extracted/firmware_extract/4325012-58052244.squashfs_v4_le_extract/usr/libexec/rtp-setup line 85:
		i=$(($i + 1))
                     ^-- SC2004 (style): $/${} is unnecessary on arithmetic variables.


In /logs/firmware/unblob_extracted/firmware_extract/4325012-58052244.squashfs_v4_le_extract/usr/libexec/rtp-setup line 93:
	[ $# -eq 1 ] && [ "$1" ] ||
                     ^-- SC2015 (info): Note that A && B || C is not if-then-else. C may run when A is true.


In /logs/firmware/unblob_extracted/firmware_extract/4325012-58052244.squashfs_v4_le_extract/usr/libexec/rtp-setup line 100:
	calculate_addresses $1
                            ^-- SC2086 (info): Double quote to prevent globbing and word splitting.

Did you mean: 
	calculate_addresses "$1"


In /logs/firmware/unblob_extracted/firmware_extract/4325012-58052244.squashfs_v4_le_extract/usr/libexec/rtp-setup line 113:
while [ $j -lt $RTP_GROUPS ]; do
               ^---------^ SC2086 (info): Double quote to prevent globbing and word splitting.

Did you mean: 
while [ $j -lt "$RTP_GROUPS" ]; do


In /logs/firmware/unblob_extracted/firmware_extract/4325012-58052244.squashfs_v4_le_extract/usr/libexec/rtp-setup line 115:
	j=$(($j + 1))
             ^-- SC2004 (style): $/${} is unnecessary on arithmetic variables.

For more information:
  https://www.shellcheck.net/wiki/SC3043 -- In POSIX sh, 'local' is undefined.
  https://www.shellcheck.net/wiki/SC1091 -- Not following: /etc/conf.d/mac wa...
  https://www.shellcheck.net/wiki/SC2015 -- Note that A && B || C is not if-t...