I have been in trouble for a while to debug some nasty problem where neighter a debugger nor printf() function is available.
I found the lowlevel debug feature in ARM Linux can be used as is in U-Boot too.
I tested this series on our SoCs (32bit ARM, specificly Coretex-A9). Because I was not sure about aarch64, I have this feature depend on "! ARM64".
1/4 and 2/4 refactor a bit and move CONFIG_ARM64 to Kconfig.
3/4 imports some source files from Linux 3.16 and 4/4 adds the Kconfig menu.
Masahiro Yamada (4): vexpress64: kconfig: consolidate CONFIG_TARGET_VEXPRESS_AEMV8A_SEMI kconfig: armv8: move CONFIG_ARM64 to Kconfig arm: debug: import debug files from Linux 3.16 arm: debug: add Kconfig entries for lowlevel debug
arch/arm/Kconfig | 13 +- arch/arm/Kconfig.debug | 64 ++++++ arch/arm/cpu/armv8/Kconfig | 7 + arch/arm/include/debug/8250.S | 54 +++++ arch/arm/lib/Makefile | 2 + arch/arm/lib/debug.S | 138 ++++++++++++ board/armltd/vexpress64/Kconfig | 24 -- board/freescale/ls2085a/Kconfig | 8 - configs/ls2085a_emu_D4_defconfig | 2 +- configs/ls2085a_emu_defconfig | 2 +- configs/ls2085a_simu_defconfig | 2 +- configs/vexpress_aemv8a_defconfig | 1 - configs/vexpress_aemv8a_semi_defconfig | 4 +- include/linux/serial_reg.h | 389 +++++++++++++++++++++++++++++++++ 14 files changed, 669 insertions(+), 41 deletions(-) create mode 100644 arch/arm/Kconfig.debug create mode 100644 arch/arm/cpu/armv8/Kconfig create mode 100644 arch/arm/include/debug/8250.S create mode 100644 arch/arm/lib/debug.S create mode 100644 include/linux/serial_reg.h