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| author | Michal Simek <monstr@monstr.eu> | 2011-11-09 15:39:58 +0100 |
|---|---|---|
| committer | Michal Simek <monstr@monstr.eu> | 2012-03-23 09:28:16 +0100 |
| commit | 173701d7745d07888a929bf08d77d29996ca13dc (patch) | |
| tree | ad86f50ce8d08b4ff51e1a0adada9a62d548e3a7 /arch/microblaze/kernel/head.S | |
| parent | cc5647a64e8c6691be87a83632d8b1c78b795023 (diff) | |
| download | op-kernel-dev-173701d7745d07888a929bf08d77d29996ca13dc.zip op-kernel-dev-173701d7745d07888a929bf08d77d29996ca13dc.tar.gz | |
microblaze: Clear all MSR flags on the first kernel instruction
The main reason is bug because of dynamic TLB allocation.
U-BOOT didn't disable dcache and then writing to physical address
from ASM wan't visible for reading through MMU.
Disabling caches and clearing all flags from previous code
is good to do so.
Signed-off-by: Michal Simek <monstr@monstr.eu>
Diffstat (limited to 'arch/microblaze/kernel/head.S')
| -rw-r--r-- | arch/microblaze/kernel/head.S | 5 |
1 files changed, 2 insertions, 3 deletions
diff --git a/arch/microblaze/kernel/head.S b/arch/microblaze/kernel/head.S index 77320b8..a5ba992 100644 --- a/arch/microblaze/kernel/head.S +++ b/arch/microblaze/kernel/head.S @@ -63,9 +63,7 @@ ENTRY(_start) real_start: #endif - mfs r1, rmsr - andi r1, r1, ~2 - mts rmsr, r1 + mts rmsr, r0 /* * According to Xilinx, msrclr instruction behaves like 'mfs rX,rpc' * if the msrclr instruction is not enabled. We use this to detect @@ -73,6 +71,7 @@ real_start: * r8 == 0 - msr instructions are implemented * r8 != 0 - msr instructions are not implemented */ + mfs r1, rmsr msrclr r8, 0 /* clear nothing - just read msr for test */ cmpu r8, r8, r1 /* r1 must contain msr reg content */ |
