Lock dcache before clearing INIT_RAM.
More importantly, invalidate dcache contents before using it as RAM.
Signed-off-by: Joakim Tjernlund <joakim.tjernl...@infinera.com>
---
Something odd happend, on a stable mpc8321 board, small unrelated code
changes made the board unbootable. Debugging with an emulator
it looked like something pulled away the dcache while it was
in early boot stages.
I found that if I let the emulator init the DDR before executing,
all was OK again.
To me this looked like there was some garbage in the dcache causing
some DDR access. All this led me to lock_ram_in_cache and the
the resluting changes in this patch.
86xx could possible need the same fix
arch/powerpc/cpu/mpc83xx/start.S | 16 ++++++++++------
1 file changed, 10 insertions(+), 6 deletions(-)
diff --git a/arch/powerpc/cpu/mpc83xx/start.S b/arch/powerpc/cpu/mpc83xx/start.S
index c00bb31363..a1f3b56433 100644
--- a/arch/powerpc/cpu/mpc83xx/start.S
+++ b/arch/powerpc/cpu/mpc83xx/start.S
@@ -1071,18 +1071,22 @@ lock_ram_in_cache:
ori r3, r3, (CONFIG_SYS_INIT_RAM_ADDR & ~31)@l
li r4, ((CONFIG_SYS_INIT_RAM_SIZE & ~31) + \
(CONFIG_SYS_INIT_RAM_ADDR & 31) + 31) / 32
+ /* Lock the data cache */
+ mfspr r0, HID0
+ ori r0, r0, HID0_DLOCK|HID0_DCFI
+ sync
+ mtspr HID0, r0
+ rlwinm r0, r0, 0, ~HID0_DCFI /* Clear HID0_DCFI */
+ sync
+ mtspr HID0, r0
+ sync
+
mtctr r4
1:
dcbz r0, r3
addi r3, r3, 32
bdnz 1b
- /* Lock the data cache */
- mfspr r0, HID0
- ori r0, r0, HID0_DLOCK
- sync
- mtspr HID0, r0
- sync
blr
#ifndef MINIMAL_SPL
--
2.26.2
