ARM: 7073/1: debug: augment DEBUG_LL Kconfig help to clarify behaviour (4f5ef922) · Commits · 戴 / test

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> Signed-off-by:

Russell King <rmk+kernel@arm.linux.org.uk>

arch/arm/Kconfig.debug

+6 −1

Original line number	Diff line number	Diff line
		@@ -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

Admin message