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 93fd03a8c6
backported.

Tested on omap3430.

Signed-off-by: Tony Lindgren <tony@atomide.com>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
This commit is contained in:
Tony Lindgren 2010-01-19 16:40:07 +01:00 committed by Russell King
parent a7b2296277
commit 200b7a8dc0
3 changed files with 40 additions and 0 deletions

View file

@ -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)