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 <[email protected]> --- arch/arm/boot/compressed/head.S | 8 ++++++++ arch/arm/boot/compressed/misc.c | 12 ++++++++++++ arch/arm/kernel/debug.S | 20 ++++++++++++++++++++ 3 files changed, 40 insertions(+), 0 deletions(-) diff --git a/arch/arm/boot/compressed/head.S b/arch/arm/boot/compressed/head.S index d356af7..4fddc50 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 17153b5..2d1e819 100644 --- a/arch/arm/boot/compressed/misc.c +++ b/arch/arm/boot/compressed/misc.c @@ -48,6 +48,18 @@ 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) diff --git a/arch/arm/kernel/debug.S b/arch/arm/kernel/debug.S index b121b60..5c91add 100644 --- a/arch/arm/kernel/debug.S +++ b/arch/arm/kernel/debug.S @@ -49,6 +49,26 @@ 1002: .endm +#elif defined(CONFIG_CPU_V7) + + .macro addruart, rx + .endm + + .macro senduart, rd, rx + mcr p14, 0, \rd, c0, c5, 0 + .endm + + .macro busyuart, rd, rx +busy: mrc p14, 0, pc, c0, c1, 0 + bcs busy + .endm + + .macro waituart, rd, rx +wait: mrc p14, 0, pc, c0, c1, 0 + bcs wait + + .endm + #elif defined(CONFIG_CPU_XSCALE) .macro addruart, rx -- To unsubscribe from this list: send the line "unsubscribe linux-omap" in the body of a message to [email protected] More majordomo info at http://vger.kernel.org/majordomo-info.html
