[PATCH] powerpc: Unify udbg (#2)

This patch unifies udbg for both ppc32 and ppc64 when building the
merged achitecture. xmon now has a single "back end". The powermac udbg
stuff gets enriched with some ADB capabilities and btext output. In
addition, the early_init callback is now called on ppc32 as well,
approx. in the same order as ppc64 regarding device-tree manipulations.
The init sequences of ppc32 and ppc64 are getting closer, I'll unify
them in a later patch.

For now, you can force udbg to the scc using "sccdbg" or to btext using
"btextdbg" on powermacs. I'll implement a cleaner way of forcing udbg
output to something else than the autodetected OF output device in a
later patch.

Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Signed-off-by: Paul Mackerras <paulus@samba.org>

1 files changed, 29 insertions, 0 deletions

diff --git a/arch/powerpc/kernel/head_32.S b/arch/powerpc/kernel/head_32.S
index ccdf94731e30..fdd34dbd8797 100644
--- a/arch/powerpc/kernel/head_32.S
+++ b/arch/powerpc/kernel/head_32.S
@@ -153,6 +153,9 @@ __after_mmu_off:
         bl      flush_tlbs
 
         bl      initial_bats
+#if !defined(CONFIG_APUS) && defined(CONFIG_BOOTX_TEXT)
+        bl      setup_disp_bat
+#endif
 
 /*
  * Call setup_cpu for CPU 0 and initialize 6xx Idle
@@ -1306,6 +1309,32 @@ initial_bats:
         blr
 
 
+#if !defined(CONFIG_APUS) && defined(CONFIG_BOOTX_TEXT)
+setup_disp_bat:
+        /*
+         * setup the display bat prepared for us in prom.c
+         */
+        mflr    r8
+        bl      reloc_offset
+        mtlr    r8
+        addis   r8,r3,disp_BAT@ha
+        addi    r8,r8,disp_BAT@l
+        cmpwi   cr0,r8,0
+        beqlr
+        lwz     r11,0(r8)
+        lwz     r8,4(r8)
+        mfspr   r9,SPRN_PVR
+        rlwinm  r9,r9,16,16,31          /* r9 = 1 for 601, 4 for 604 */
+        cmpwi   0,r9,1
+        beq     1f
+        mtspr   SPRN_DBAT3L,r8
+        mtspr   SPRN_DBAT3U,r11
+        blr
+1:      mtspr   SPRN_IBAT3L,r8
+        mtspr   SPRN_IBAT3U,r11
+        blr
+#endif /* !defined(CONFIG_APUS) && defined(CONFIG_BOOTX_TEXT) */
+
 #ifdef CONFIG_8260
 /* Jump into the system reset for the rom.
  * We first disable the MMU, and then jump to the ROM reset address.