[POWERPC] 4xx: Add early udbg support for 40x processors
This adds some basic real mode based early udbg support for 40x
in order to debug things more easily
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Signed-off-by: Josh Boyer <jwboyer@linux.vnet.ibm.com>
diff --git a/arch/powerpc/kernel/misc_32.S b/arch/powerpc/kernel/misc_32.S
index ea11378..be09f0d 100644
--- a/arch/powerpc/kernel/misc_32.S
+++ b/arch/powerpc/kernel/misc_32.S
@@ -206,6 +206,45 @@
isync
blr /* Done */
+#ifdef CONFIG_40x
+
+/*
+ * Do an IO access in real mode
+ */
+_GLOBAL(real_readb)
+ mfmsr r7
+ ori r0,r7,MSR_DR
+ xori r0,r0,MSR_DR
+ sync
+ mtmsr r0
+ sync
+ isync
+ lbz r3,0(r3)
+ sync
+ mtmsr r7
+ sync
+ isync
+ blr
+
+ /*
+ * Do an IO access in real mode
+ */
+_GLOBAL(real_writeb)
+ mfmsr r7
+ ori r0,r7,MSR_DR
+ xori r0,r0,MSR_DR
+ sync
+ mtmsr r0
+ sync
+ isync
+ stb r3,0(r4)
+ sync
+ mtmsr r7
+ sync
+ isync
+ blr
+
+#endif /* CONFIG_40x */
/*
* Flush MMU TLB