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authorMichal Simek <monstr@monstr.eu>2010-03-15 08:48:27 +0100
committerMichal Simek <monstr@monstr.eu>2010-04-01 08:38:23 +0200
commitee68f1745e7734a55c8bf680f6f464205f1f15da (patch)
tree25fb85eb407389adf81419c045415882090bb1f1 /arch/microblaze/kernel/head.S
parent89ae9753aef160c2f7bcecec21a7c4a6bc4c9b9b (diff)
downloadop-kernel-dev-ee68f1745e7734a55c8bf680f6f464205f1f15da.zip
op-kernel-dev-ee68f1745e7734a55c8bf680f6f464205f1f15da.tar.gz
microblaze: Support systems without lmb bram
When the system has no lmb bram, main memory should be start from zero because of microblaze vectors. DTS fragment could look like: DDR2_SDRAM: memory@0 { device_type = "memory"; reg = < 0x0 0x10000000 >; } ; Then you have to setup CONFIG_KERNEL_BASE_ADDR=0 which caused that kernel physical start address will be zero. On reset vector place will be jump to 0x100 and on 0x100 starts kernel text. You have to solve how to load the kernel before cpu starts. Tested with XMD. Signed-off-by: Michal Simek <monstr@monstr.eu>
Diffstat (limited to 'arch/microblaze/kernel/head.S')
-rw-r--r--arch/microblaze/kernel/head.S6
1 files changed, 6 insertions, 0 deletions
diff --git a/arch/microblaze/kernel/head.S b/arch/microblaze/kernel/head.S
index cb7815c..e397d5d 100644
--- a/arch/microblaze/kernel/head.S
+++ b/arch/microblaze/kernel/head.S
@@ -51,6 +51,12 @@ swapper_pg_dir:
.text
ENTRY(_start)
+#if CONFIG_KERNEL_BASE_ADDR == 0
+ brai TOPHYS(real_start)
+ .org 0x100
+real_start:
+#endif
+
mfs r1, rmsr
andi r1, r1, ~2
mts rmsr, r1
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