--- zzzz-none-000/linux-4.1.52/drivers/mtd/cmdlinepart.c	2018-05-28 02:26:45.000000000 +0000
+++ bcm63-7530ax-731/linux-4.1.52/drivers/mtd/cmdlinepart.c	2022-03-02 11:37:13.000000000 +0000
@@ -46,6 +46,22 @@
  *
  * 1 NOR Flash with 2 partitions, 1 NAND with one
  * edb7312-nor:256k(ARMboot)ro,-(root);edb7312-nand:-(home)
+ *
+ * ==========================================================================
+ * AVM extensions
+ * --------------
+ *
+ *  A new command line parameter 'mtdparts_ext' was introduced with
+ *  same format as 'mtdparts' above.
+ *
+ *  The semantics of 'mtdparts' force a complete override of previously
+ *  given parameters in case another 'mtdparts' entry is found.
+ *
+ *  All 'mtdparts_ext' entries however are appended.
+ *  When the parser kicks in the first time, the kernel's 'mtdparts'
+ *  is appended to the 'mtdparts_ext' collection, so that the system is fed
+ *  with the complete information.
+ * ==========================================================================
  */
 
 #include <linux/kernel.h>
@@ -54,6 +70,9 @@
 #include <linux/mtd/partitions.h>
 #include <linux/module.h>
 #include <linux/err.h>
+#include <asm/setup.h>
+
+#include <asm/avm_enh/avm_mtd.h>
 
 /* error message prefix */
 #define ERRP "mtd: "
@@ -82,9 +101,23 @@
 
 /* the command line passed to mtdpart_setup() */
 static char *mtdparts;
-static char *cmdline;
+static char *system_cmdline;
 static int cmdline_parsed;
 
+static int cmdline_locked;
+static char avm_cmdline_mtd_ext[AVM_MAX_CMDLINE_MTD_EXT + COMMAND_LINE_SIZE + 1];
+
+
+static int mtdpart_setup_ext(char *s);
+
+static char *cmdline(void)
+{
+	if (!cmdline_locked)
+		mtdpart_setup_ext(system_cmdline);
+	cmdline_locked = 1;
+	return avm_cmdline_mtd_ext;
+}
+
 /*
  * Parse one partition definition for an MTD. Since there can be many
  * comma separated partition definitions, this function calls itself
@@ -316,7 +349,7 @@
 
 	/* parse command line */
 	if (!cmdline_parsed) {
-		err = mtdpart_setup_real(cmdline);
+		err = mtdpart_setup_real(cmdline());
 		if (err)
 			return err;
 	}
@@ -379,11 +412,28 @@
  */
 static int __init mtdpart_setup(char *s)
 {
-	cmdline = s;
+	system_cmdline = s;
+	return 1;
+}
+
+static int mtdpart_setup_ext(char *s)
+{
+	size_t len = strlen(avm_cmdline_mtd_ext);
+
+	if (len && (strlen(s) > 0))
+		(void)strlcat(avm_cmdline_mtd_ext, ";", AVM_MAX_CMDLINE_MTD_EXT);
+
+	if (strlcat(avm_cmdline_mtd_ext, s, AVM_MAX_CMDLINE_MTD_EXT) > AVM_MAX_CMDLINE_MTD_EXT) {
+		avm_cmdline_mtd_ext[len] = 0;
+		pr_err("[%s] ERROR: cmdline part \"%s\" dropped!", __func__, s);
+		return 0;
+	}
+
 	return 1;
 }
 
 __setup("mtdparts=", mtdpart_setup);
+__setup("mtdparts_ext=", mtdpart_setup_ext);
 
 static struct mtd_part_parser cmdline_parser = {
 	.owner = THIS_MODULE,