From: "Cohen, Eugene" <eugene@xxxxxx> The UEFI Specification permits Graphics Output Protocol (GOP) instances without direct framebuffer access. This is indicated in the Mode structure with a PixelFormat enumeration value of PIXEL_BLT_ONLY. Given that the kernel does not know how to drive a Blt() only framebuffer (which is only permitted before ExitBootServices() anyway), we should disregard such framebuffers when looking for a GOP instance that is suitable for use as the boot console. So modify the EFI GOP initialization to not use a PIXEL_BLT_ONLY instance, preventing attempts later in boot to use an invalid screen_info.lfb_base address. Signed-off-by: Eugene Cohen <eugene@xxxxxx> [ardb: clarify that Blt() only GOPs are unusable by the kernel] Signed-off-by: Ard Biesheuvel <ard.biesheuvel@xxxxxxxxxx> --- drivers/firmware/efi/libstub/gop.c | 8 ++++++++ 1 file changed, 8 insertions(+) diff --git a/drivers/firmware/efi/libstub/gop.c b/drivers/firmware/efi/libstub/gop.c index 932742e4cf23..b05b282b470d 100644 --- a/drivers/firmware/efi/libstub/gop.c +++ b/drivers/firmware/efi/libstub/gop.c @@ -178,6 +178,10 @@ setup_gop32(efi_system_table_t *sys_table_arg, struct screen_info *si, if (!first_gop) goto out; + /* Does the GOP implement a BLT-only framebuffer? */ + if (pixel_format == PIXEL_BLT_ONLY) + goto out; + /* EFI framebuffer */ si->orig_video_isVGA = VIDEO_TYPE_EFI; @@ -295,6 +299,10 @@ setup_gop64(efi_system_table_t *sys_table_arg, struct screen_info *si, if (!first_gop) goto out; + /* Does the GOP implement a BLT-only framebuffer? */ + if (pixel_format == PIXEL_BLT_ONLY) + goto out; + /* EFI framebuffer */ si->orig_video_isVGA = VIDEO_TYPE_EFI; -- 2.7.4 -- To unsubscribe from this list: send the line "unsubscribe linux-efi" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
