This is a WIP series (I have no time to continue with it, so, that's why WIP) to enable SPCR table generation in U-Boot. This table is useful to get early console in Linux for debugging purposes. The benefit of using it is not only for x86, but also for arm64 community (actually they introduced support in Linux kernel).
This PoC implementation has been tested on Intel Edison with enabled ACPI support.
Known issues: - there is no ->getconfig() callback, thus some data is hard coded - if serial parameters are changed at run time, SPCR is not regenerated, thus, might not produce what user excepts (this is more likely design issue of U-Boot itself) - implementation is not final and might not utilize best practices in U-Boot
So, if there is any interest, I would be happy to help, but as I mentioned above I have no capacity to continue this myself.
The patches would be also available through my U-Boot tree on GH.
Andy Shevchenko (2): WIP: serial: Introduce ->getinfo() callback WIP: x86: acpi: Generate SPCR table
arch/x86/include/asm/acpi_table.h | 25 ++++++++++ arch/x86/lib/acpi_table.c | 82 +++++++++++++++++++++++++++++++ drivers/serial/ns16550.c | 14 ++++++ drivers/serial/serial-uclass.c | 21 ++++++++ include/common.h | 3 ++ include/serial.h | 14 ++++++ 6 files changed, 159 insertions(+)