@@ -65,13 +65,18 @@ config DEBUG_USER
# These options are only for real kernel hackers who want to get their hands dirty.
config DEBUG_LL
- bool "Kernel low-level debugging functions"
+ bool "Kernel low-level debugging functions (read help!)"
depends on DEBUG_KERNEL
help
Say Y here to include definitions of printascii, printch, printhex
in the kernel. This is helpful if you are debugging code that
executes before the console is initialized.
+ Note that selecting this option will limit the kernel to a single
+ UART definition, as specified below. Attempting to boot the kernel
+ image on a different platform *will not work*, so this option should
+ not be enabled for kernels that are intended to be portable.
+
choice
prompt "Kernel low-level debugging port"
depends on DEBUG_LL
Enabled DEBUG_LL hardcodes the UART address into the kernel and results in a non-portable kernel image. Since this option is only intended for use when debugging early boot failures, supporting multiple platforms in such a configuration is not the intended use-case. This patch documents this limitation in the DEBUG_LL Kconfig help text, so that users are aware of the portability restrictions that are associated with enabling low-level debugging support. Reported-by: Sascha Hauer <s.hauer@pengutronix.de> Signed-off-by: Will Deacon <will.deacon@arm.com> --- arch/arm/Kconfig.debug | 7 ++++++- 1 files changed, 6 insertions(+), 1 deletions(-)