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authorTony Lindgren <tony@atomide.com>2010-01-19 16:40:07 +0100
committerRussell King <rmk+kernel@arm.linux.org.uk>2010-01-19 20:23:16 +0000
commit200b7a8dc09504bc0aedac567a307a6e533f39e5 (patch)
treeec735fed9611efcbafd4982cb015eab58b552f27 /arch/arm/boot
parenta7b22962776109b5bfe3a3efa4f42622318c547d (diff)
ARM: 5884/1: arm: Fix DCC console for v7
Without this patch arch/arm/compressed/head.S defaults to generic DCC code that does not work for v7. For more information on the v7 DCC, see Cortex-A8 TRM "12.11.1 Debug communications channel". To use it with post 2.6.33-rc1 or later, you need to have: CONFIG_DEBUG_LL=y ONFIG_DEBUG_ICEDCC=y CONFIG_EARLY_PRINTK=y Earlier kernels need commit 93fd03a8c6728b58879f8af20ffd55d9c32a778b backported. Tested on omap3430. Signed-off-by: Tony Lindgren <tony@atomide.com> Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
Diffstat (limited to 'arch/arm/boot')
-rw-r--r--arch/arm/boot/compressed/head.S8
-rw-r--r--arch/arm/boot/compressed/misc.c12
2 files changed, 20 insertions, 0 deletions
diff --git a/arch/arm/boot/compressed/head.S b/arch/arm/boot/compressed/head.S
index d356af7cef82..4fddc509e78e 100644
--- a/arch/arm/boot/compressed/head.S
+++ b/arch/arm/boot/compressed/head.S
@@ -27,6 +27,14 @@
.macro writeb, ch, rb
mcr p14, 0, \ch, c0, c5, 0
.endm
+#elif defined(CONFIG_CPU_V7)
+ .macro loadsp, rb
+ .endm
+ .macro writeb, ch, rb
+wait: mrc p14, 0, pc, c0, c1, 0
+ bcs wait
+ mcr p14, 0, \ch, c0, c5, 0
+ .endm
#elif defined(CONFIG_CPU_XSCALE)
.macro loadsp, rb
.endm
diff --git a/arch/arm/boot/compressed/misc.c b/arch/arm/boot/compressed/misc.c
index af6479fae931..56a0d116d271 100644
--- a/arch/arm/boot/compressed/misc.c
+++ b/arch/arm/boot/compressed/misc.c
@@ -53,6 +53,18 @@ static void icedcc_putc(int ch)
asm("mcr p14, 0, %0, c0, c5, 0" : : "r" (ch));
}
+
+#elif defined(CONFIG_CPU_V7)
+
+static void icedcc_putc(int ch)
+{
+ asm(
+ "wait: mrc p14, 0, pc, c0, c1, 0 \n\
+ bcs wait \n\
+ mcr p14, 0, %0, c0, c5, 0 "
+ : : "r" (ch));
+}
+
#elif defined(CONFIG_CPU_XSCALE)
static void icedcc_putc(int ch)