83xx: Use the proper sequence for updating IMMR.
This ensures that subsequent accesses properly hit the new window.
The dcbi during the NAND loop was accidentally working around this;
it's no longer necessary, as the cache is not enabled.
Reported-by: Suchit Lepcha <Suchit.Lepcha@freescale.com>
Signed-off-by: Scott Wood <scottwood@freescale.com>
Signed-off-by: Kim Phillips <kim.phillips@freescale.com>
diff --git a/cpu/mpc83xx/start.S b/cpu/mpc83xx/start.S
index beebc99..26e3106 100644
--- a/cpu/mpc83xx/start.S
+++ b/cpu/mpc83xx/start.S
@@ -200,9 +200,23 @@
nop
boot_warm: /* time t 5 */
mfmsr r5 /* save msr contents */
+
+ /* 83xx manuals prescribe a specific sequence for updating IMMRBAR. */
+ bl 1f
+1: mflr r7
+
lis r3, CONFIG_SYS_IMMR@h
ori r3, r3, CONFIG_SYS_IMMR@l
+
+ lwz r6, IMMRBAR(r4)
+ isync
+
stw r3, IMMRBAR(r4)
+ lwz r6, 0(r7) /* Arbitrary external load */
+ isync
+
+ lwz r6, IMMRBAR(r3)
+ isync
/* Initialise the E300 processor core */
/*------------------------------------------*/
@@ -212,9 +226,7 @@
* is loaded. Wait for the rest before branching
* to another flash page.
*/
- addi r7, r3, 0x50b0
-1: dcbi 0, r7
- lwz r6, 0(r7)
+1: lwz r6, 0x50b0(r3)
andi. r6, r6, 1
beq 1b
#endif