microblaze: Fix stack protection behavior

When U-Boot starts stack protection can be already enabled that's why setup
the lowest possible SLR value which is address 0. And the highest possible
stack in front of U-Boot. That's why you should never load U-Boot to the
beginning of DDR. There must be some space reserved. Code is using this
location for early malloc space, early global data and stack.

Signed-off-by: Michal Simek <michal.simek@amd.com>
Link: https://lore.kernel.org/r/86b9748bad12142659804d6381bc6bbf20be44f1.1655299267.git.michal.simek@amd.com

diff --git a/arch/microblaze/cpu/start.S b/arch/microblaze/cpu/start.S
index 9e00eef1f4b69f59df8c198db1f02e4b6de07422..715ef37b39d92332c7e05a3d2c4e0a0df68f8e1d 100644 (file)
--- a/arch/microblaze/cpu/start.S
+++ b/arch/microblaze/cpu/start.S
@@ -15,8 +15,9 @@
 _start:
        mts     rmsr, r0        /* disable cache */
 
-       addi    r8, r0, _end
-       mts     rslr, r8
+       mts     rslr, r0
+       addi    r8, r0, _start
+       mts     rshr, r8
 
 #if defined(CONFIG_SPL_BUILD)
        addi    r1, r0, CONFIG_SPL_STACK_ADDR