In /logs/firmware/unblob_extracted/firmware_extract/1568982-13971496.squashfs_v4_le_extract/lib/preinit/07_set_preinit_iface_ramips line 6:

. /lib/ramips.sh

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

In /logs/firmware/unblob_extracted/firmware_extract/1568982-13971496.squashfs_v4_le_extract/lib/preinit/07_set_preinit_iface_ramips line 9:

	RT3X5X=`cat /proc/cpuinfo | egrep "(RT3.5|RT5350|MT7628|MT7688|MT7620|MT7621)"`

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

                    ^-----------^ SC2002 (style): Useless cat. Consider 'cmd < file | ..' or 'cmd file | ..' instead.

                                    ^---^ SC2196 (info): egrep is non-standard and deprecated. Use grep -E instead.

Did you mean: 

	RT3X5X=$(cat /proc/cpuinfo | egrep "(RT3.5|RT5350|MT7628|MT7688|MT7620|MT7621)")

In /logs/firmware/unblob_extracted/firmware_extract/1568982-13971496.squashfs_v4_le_extract/lib/preinit/07_set_preinit_iface_ramips line 31:

	ifname=eth0

        ^----^ SC2034 (warning): ifname appears unused. Verify use (or export if used externally).

For more information:

  https://www.shellcheck.net/wiki/SC2034 -- ifname appears unused. Verify use...

  https://www.shellcheck.net/wiki/SC1091 -- Not following: /lib/ramips.sh was...

  https://www.shellcheck.net/wiki/SC2196 -- egrep is non-standard and depreca...