ARM: 7072/1: debug: use kconfig choice for selecting DEBUG_LL UART

Enabling CONFIG_DEBUG_LL (which is required for earlyprintk) hardwires
the debug UART address into the kernel, so that we can print before the
platform is initialised.

If the user inadvertently selects multiple platforms with DEBUG_LL
enabled, the UART address may not be correct and will likely cause the
kernel to hang in the very early stages of boot.

This patch, based on a skeleton from Russell, uses a Kconfig choice for
selecting the DEBUG_LL UART, therefore allowing the user to make a
choice about the supported platform when DEBUG_LL is enabled.

Acked-by: Nicolas Pitre <nicolas.pitre@linaro.org>
Signed-off-by: Will Deacon <will.deacon@arm.com>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
This commit is contained in:
Will Deacon 2011-09-01 18:58:51 +01:00 committed by Russell King
parent d0a77454c7
commit 17916b284e

View file

@ -72,6 +72,30 @@ config DEBUG_LL
in the kernel. This is helpful if you are debugging code that
executes before the console is initialized.
choice
prompt "Kernel low-level debugging port"
depends on DEBUG_LL
config DEBUG_DC21285_PORT
bool "Kernel low-level debugging messages via footbridge serial port"
depends on FOOTBRIDGE
help
Say Y here if you want the debug print routines to direct
their output to the serial port in the DC21285 (Footbridge).
Saying N will cause the debug messages to appear on the first
16550 serial port.
config DEBUG_CLPS711X_UART2
bool "Kernel low-level debugging messages via UART2"
depends on ARCH_CLPS711X
help
Say Y here if you want the debug print routines to direct
their output to the second serial port on these devices.
Saying N will cause the debug messages to appear on the first
serial port.
endchoice
config EARLY_PRINTK
bool "Early printk"
depends on DEBUG_LL
@ -100,23 +124,6 @@ config OC_ETM
buffer driver that will allow you to collect traces of the
kernel code.
config DEBUG_DC21285_PORT
bool "Kernel low-level debugging messages via footbridge serial port"
depends on DEBUG_LL && FOOTBRIDGE
help
Say Y here if you want the debug print routines to direct their
output to the serial port in the DC21285 (Footbridge). Saying N
will cause the debug messages to appear on the first 16550
serial port.
config DEBUG_CLPS711X_UART2
bool "Kernel low-level debugging messages via UART2"
depends on DEBUG_LL && ARCH_CLPS711X
help
Say Y here if you want the debug print routines to direct their
output to the second serial port on these devices. Saying N will
cause the debug messages to appear on the first serial port.
config DEBUG_S3C_UART
depends on PLAT_SAMSUNG
int "S3C UART to use for low-level debug"