HACK: Pass data from firmware to kernel

arch/arm/lib/bootm.c

 /*
  * (C) Copyright 2002
  * Sysgo Real-Time Solutions, GmbH <www.elinos.com>
  * Marius Groeger <mgroeger@sysgo.de>
  *
  * Copyright (C) 2001  Erik Mouw (J.A.K.Mouw@its.tudelft.nl)
  *
  * This program is free software; you can redistribute it and/or modify
  * it under the terms of the GNU General Public License as published by
  * the Free Software Foundation; either version 2 of the License, or
@@ skipping 12 matching lines @@
 
 #include <common.h>
 #include <command.h>
 #include <image.h>
 #include <u-boot/zlib.h>
 #include <asm/byteorder.h>
 #include <fdt.h>
 #include <libfdt.h>
 #include <fdt_support.h>
 
+/*
+ * TODO(clchiou): This is an urgent hack for bringing up factory. We need to
+ * enable setup memory tags.
+ *
+ * Remove this part or move to config headers after the protocol specification
+ * between Chrome OS firmware and kernel is finalized.
+ */
+#ifndef CONFIG_SETUP_MEMORY_TAGS
+#define CONFIG_SETUP_MEMORY_TAGS
+#endif
+
 DECLARE_GLOBAL_DATA_PTR;
 
 #if defined (CONFIG_SETUP_MEMORY_TAGS) || \
     defined (CONFIG_CMDLINE_TAG) || \
     defined (CONFIG_INITRD_TAG) || \
     defined (CONFIG_SERIAL_TAG) || \
     defined (CONFIG_REVISION_TAG)
 static void setup_start_tag (bd_t *bd);
 
 # ifdef CONFIG_SETUP_MEMORY_TAGS
@@ skipping 217 matching lines @@
 {
         int i;
 
         for (i = 0; i < CONFIG_NR_DRAM_BANKS; i++) {
                 params->hdr.tag = ATAG_MEM;
                 params->hdr.size = tag_size (tag_mem32);
 
                 params->u.mem.start = bd->bi_dram[i].start;
                 params->u.mem.size = bd->bi_dram[i].size;
 
+                /*
+                 * TODO(clchiou): This is an urgent hack for bringing up
+                 * factory. Here we reserve 1MB static area for passing data
+                 * from firmware to kernel.
+                 *
+                 * Rewrite this part after the protocol specification between
+                 * Chrome OS firmware and kernel is finalized.
+                 */
+                if (i == CONFIG_NR_DRAM_BANKS - 1)
+                        params->u.mem.size -= SZ_1M;
+
                 params = tag_next (params);
         }
 }
 #endif /* CONFIG_SETUP_MEMORY_TAGS */
 
 
 static void setup_commandline_tag (bd_t *bd, char *commandline)
 {
         char *p;
 
@@ skipping 100 matching lines @@
 
 static ulong get_sp(void)
 {
         ulong ret;
 
         asm("mov %0, sp" : "=r"(ret) : );
         return ret;
 }
 
 #endif /* CONFIG_SETUP_MEMORY_TAGS || CONFIG_CMDLINE_TAG || CONFIG_INITRD_TAG */