feat(zbm): In Syslinux/extlinux mode add KCL (#6)

setup.sh

@@ -832,8 +832,31 @@ function customize_dropbear_hooks () {
     fi
 }
 
+function set_unique_ip_in_syslinux_kcl () {
+    local zbm_config default_ip
+    zbm_config="${1:?}"
+    default_ip="${2:?}"
+
+    # First -e expression removes first looks for lines that contain
+    # 'APPEND' plus a space character and only in those lines removes all
+    # occurrences of ' ip=' followed by as many non-space characters as
+    # possible. This removes whatever 'ip=' definition already was present.
+    #
+    # Second -e expression similarly looks for lines that contain 'APPEND'
+    # plus a space character then at their end inserts a space plus our
+    # desired new 'ip=' definition. This puts in place the 'ip=' we want.
+    sed -ri \
+        -e \\$'\x1''APPEND '$'\x1 s'$'\x1'' ip=([^[:space:]]*)'$'\x1'''$'\x1''gi' \
+        -e \\$'\x1''APPEND '$'\x1 s'$'\x1''$'$'\x1'' '"${default_ip}"''$'\x1''gi' \
+        "${zbm_config}"
+}
+
 function ensure_ip_in_kcl () {
-    local zbm_config kcl_length kcl_string default_ip ip_addr_found new_kcl first_kcl_elem
+    local default_ip
+    default_ip='ip='"${ARCHZBM_NET_CLIENT_IP}"':'"${ARCHZBM_NET_SERVER_IP}"':'"${ARCHZBM_NET_GATEWAY_IP}"':'"${ARCHZBM_NET_NETMASK}"':'"${ARCHZBM_NET_HOSTNAME}"':'"${ARCHZBM_NET_DEVICE}"':'"${ARCHZBM_NET_AUTOCONF}"
+
+    if [[ "${part_schema}" = 'gpt' ]]; then
+        local zbm_config kcl_length kcl_string ip_addr_found new_kcl first_kcl_elem
         local -a kcl
         paru_install 'go-yq'
 
@@ -847,7 +870,6 @@ function ensure_ip_in_kcl () {
             kcl_string="$(yq '.Kernel.CommandLine' "${zbm_config}")"
         fi
 
-    default_ip='ip='"${ARCHZBM_NET_CLIENT_IP}"':'"${ARCHZBM_NET_SERVER_IP}"':'"${ARCHZBM_NET_GATEWAY_IP}"':'"${ARCHZBM_NET_NETMASK}"':'"${ARCHZBM_NET_HOSTNAME}"':'"${ARCHZBM_NET_DEVICE}"':'"${ARCHZBM_NET_AUTOCONF}"
         mapfile -t kcl < <(<<<"${kcl_string}" tr ' ' '\n' | sed '/^$/d')
         for kcl_elem in "${!kcl[@]}"; do
             if grep -Piq -- 'ip=' <<<"${kcl[$kcl_elem]}"; then
@@ -869,6 +891,11 @@ function ensure_ip_in_kcl () {
             fi
         done
         yq -i '.Kernel.CommandLine = "'"${new_kcl}"'"' "${zbm_config}"
+    else
+        local zbm_config
+        zbm_config='/boot/syslinux/syslinux.cfg'
+        set_unique_ip_in_syslinux_kcl "${zbm_config}" "${default_ip}"
+    fi
 }
 
 function set_pub_keys () {