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path: root/arch/x86/platform/efi/early_printk.c
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2013-11-28x86/efi: Fix earlyprintk off-by-one bugMatt Fleming
Dave reported seeing the following incorrect output on his Thinkpad T420 when using earlyprintk=efi, [ 0.000000] efi: EFI v2.00 by Lenovo ACPI=0xdabfe000 ACPI 2.0=0xdabfe014 SMBIOS=0xdaa9e000 The output should be on one line, not split over two. The cause is an off-by-one error when checking that the efi_y coordinate hasn't been incremented out of bounds. Reported-by: Dave Young <dyoung@redhat.com> Signed-off-by: Matt Fleming <matt.fleming@intel.com>
2013-10-28x86/efi: Add EFI framebuffer earlyprintk supportMatt Fleming
It's incredibly difficult to diagnose early EFI boot issues without special hardware because earlyprintk=vga doesn't work on EFI systems. Add support for writing to the EFI framebuffer, via earlyprintk=efi, which will actually give users a chance of providing debug output. Cc: H. Peter Anvin <hpa@zytor.com> Acked-by: Ingo Molnar <mingo@kernel.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Peter Jones <pjones@redhat.com> Signed-off-by: Matt Fleming <matt.fleming@intel.com>