1 files changed, 45 insertions, 0 deletions
diff --git a/arch/arm/lib/stack.c b/arch/arm/lib/stack.c
index b03e1cfc80c..3f961f44543 100644
--- a/arch/arm/lib/stack.c
+++ b/arch/arm/lib/stack.c
@@ -12,6 +12,7 @@
  */
 #include <common.h>
 #include <init.h>
+#include <lmb.h>
 #include <asm/global_data.h>
 
 DECLARE_GLOBAL_DATA_PTR;
@@ -33,3 +34,47 @@ int arch_reserve_stacks(void)
 
 	return 0;
 }
+
+static ulong get_sp(void)
+{
+	ulong ret;
+
+	asm("mov %0, sp" : "=r"(ret) : );
+	return ret;
+}
+
+void arch_lmb_reserve(struct lmb *lmb)
+{
+	ulong sp, bank_end;
+	int bank;
+
+	/*
+	 * Booting a (Linux) kernel image
+	 *
+	 * Allocate space for command line and board info - the
+	 * address should be as high as possible within the reach of
+	 * the kernel (see CONFIG_SYS_BOOTMAPSZ settings), but in unused
+	 * memory, which means far enough below the current stack
+	 * pointer.
+	 */
+	sp = get_sp();
+	debug("## Current stack ends at 0x%08lx ", sp);
+
+	/* adjust sp by 4K to be safe */
+	sp -= 4096;
+	for (bank = 0; bank < CONFIG_NR_DRAM_BANKS; bank++) {
+		if (!gd->bd->bi_dram[bank].size ||
+		    sp < gd->bd->bi_dram[bank].start)
+			continue;
+		/* Watch out for RAM at end of address space! */
+		bank_end = gd->bd->bi_dram[bank].start +
+			gd->bd->bi_dram[bank].size - 1;
+		if (sp > bank_end)
+			continue;
+		if (bank_end > gd->ram_top)
+			bank_end = gd->ram_top - 1;
+
+		lmb_reserve(lmb, sp, bank_end - sp + 1);
+		break;
+	}
+}