From ee68f1745e7734a55c8bf680f6f464205f1f15da Mon Sep 17 00:00:00 2001 From: Michal Simek Date: Mon, 15 Mar 2010 08:48:27 +0100 Subject: [PATCH] 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 --- arch/microblaze/kernel/head.S | 6 ++++++ 1 file changed, 6 insertions(+) diff --git a/arch/microblaze/kernel/head.S b/arch/microblaze/kernel/head.S index cb7815cfe5ab..e397d5d52571 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