[PATCH] ARM: map ATAGs when not in first 1MB of RAM
Rob Herring
robherring2 at gmail.com
Fri Jan 28 02:50:43 EST 2011
From: Rob Herring <rob.herring at calxeda.com>
If ATAGs or DTB pointer is not within first 1MB of RAM, then the boot params
will not be mapped early enough, so map the 1MB region that r2 points to. Only
map the first 1MB when r2 is 0.
Some assembly improvements from Nicolas Pitre.
Signed-off-by: Rob Herring <rob.herring at calxeda.com>
---
arch/arm/kernel/head.S | 19 ++++++++++++++++++-
1 files changed, 18 insertions(+), 1 deletions(-)
diff --git a/arch/arm/kernel/head.S b/arch/arm/kernel/head.S
index 65d9489..9c688bf 100644
--- a/arch/arm/kernel/head.S
+++ b/arch/arm/kernel/head.S
@@ -205,15 +205,32 @@ __create_page_tables:
#endif
/*
- * Then map first 1MB of ram in case it contains our boot params.
+ * Then map first 1MB of ram if boot params address is not specified.
*/
+ cmp r2, #0
+ bne 1f
add r0, r4, #PAGE_OFFSET >> 18
orr r6, r7, #(PHYS_OFFSET & 0xff000000)
.if (PHYS_OFFSET & 0x00f00000)
orr r6, r6, #(PHYS_OFFSET & 0x00f00000)
.endif
str r6, [r0]
+ b 2f
+ /*
+ * Otherwise map the 1MB region r2 points to (atags or dtb)
+ */
+1: mov r0, r2, lsr #20
+ mov r0, r0, lsl #20
+ sub r3, r0, #(PHYS_OFFSET & 0xff000000)
+ .if (PHYS_OFFSET & 0x00f00000)
+ sub r3, r3, #(PHYS_OFFSET & 0x00f00000)
+ .endif
+ add r3, r3, #PAGE_OFFSET
+ add r3, r4, r3, lsr #18
+ orr r6, r7, r0
+ str r6, [r3]
+2:
#ifdef CONFIG_DEBUG_LL
#ifndef CONFIG_DEBUG_ICEDCC
/*
--
1.7.1
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