Support for configuring bootconsole and console via the ACPI tables DBG2 (Debug Port Table 2) [1] and SPCR (Serial Port Console Redirection Table) [2], defined by Microsoft, has been discussed on and off over the years. [1] https://msdn.microsoft.com/en-us/library/windows/hardware/dn639131(v=vs.85).aspx [2] https://msdn.microsoft.com/en-us/library/windows/hardware/dn639132(v=vs.85).aspx Licensing concerns have prevented this happening in the past, but as of 10 August 2015, these tables have both been released also under OWF 1.0 (http://www.openwebfoundation.org/legal/the-owf-1-0-agreements/owfa-1-0) which is think is noncontroversially GPL-compatible? This set is a first attempt at implementing this. Submitting as an RFC since the SPCR handling currently depends on the console driver being initialized after subsystem initcalls. Workaround to enable testing surrounding infrastructure in 5/5, _really_ not intended to be merged. (Suggestions for acceptable ways of working around this appreciated.) For testing the DBG2 stuff with pl011, you would need: - A patch to unbreak pl011 earlycon, like http://permalink.gmane.org/gmane.linux.ports.arm.kernel/433219 - A QEMU that generates DBG2 tables, like current HEAD with the addition of http://lists.nongnu.org/archive/html/qemu-devel/2015-09/msg01719.html SPCR support is included in QEMU's ARM mach-virt since 2.4 release. DBG2 support has an Intel copyright notice added to it since my starting point was Lv Zheng's 2012 DBGP/DBG2 set (although not much of the original remains - this is quite a cut-down version). Leif Lindholm (4): arm64: move acpi/dt decision earlier in boot process of/serial: move earlycon early_param handling to serial acpi/serial: add DBG2 earlycon support HACK: serial: move pl011 initcall to device_initcall Torez Smith (1): tty/console: use SPCR table to define console arch/arm64/kernel/acpi.c | 55 +++++---- drivers/acpi/Makefile | 1 + drivers/acpi/console.c | 260 +++++++++++++++++++++++++++++++++++++++ drivers/of/fdt.c | 13 +- drivers/tty/serial/amba-pl011.c | 2 +- drivers/tty/serial/earlycon.c | 18 ++- drivers/tty/serial/serial_core.c | 14 ++- include/linux/acpi.h | 13 ++ include/linux/of_fdt.h | 1 + include/linux/serial_core.h | 9 +- 10 files changed, 337 insertions(+), 49 deletions(-) create mode 100644 drivers/acpi/console.c -- 2.1.4 -- To unsubscribe from this list: send the line "unsubscribe devicetree" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
