From 801820bee9bccb7c156af2b95c7208f428a06ae7 Mon Sep 17 00:00:00 2001 From: Ard Biesheuvel Date: Mon, 25 Apr 2016 21:06:53 +0100 Subject: efi/arm/libstub: Make screen_info accessible to the UEFI stub In order to hand over the framebuffer described by the GOP protocol and discovered by the UEFI stub, make struct screen_info accessible by the stub. This involves allocating a loader data buffer and passing it to the kernel proper via a UEFI Configuration Table, since the UEFI stub executes in the context of the decompressor, and cannot access the kernel's copy of struct screen_info directly. Signed-off-by: Ard Biesheuvel Signed-off-by: Matt Fleming Cc: Borislav Petkov Cc: David Herrmann Cc: Mark Rutland Cc: Peter Jones Cc: Peter Zijlstra Cc: Thomas Gleixner Cc: Will Deacon Cc: linux-efi@vger.kernel.org Link: http://lkml.kernel.org/r/1461614832-17633-22-git-send-email-matt@codeblueprint.co.uk Signed-off-by: Ingo Molnar --- drivers/firmware/efi/arm-init.c | 34 +++++++++++++++++++++++++++++++++- 1 file changed, 33 insertions(+), 1 deletion(-) (limited to 'drivers/firmware/efi/arm-init.c') diff --git a/drivers/firmware/efi/arm-init.c b/drivers/firmware/efi/arm-init.c index 909d974d35d9..ac95dd8b119f 100644 --- a/drivers/firmware/efi/arm-init.c +++ b/drivers/firmware/efi/arm-init.c @@ -11,12 +11,15 @@ * */ +#define pr_fmt(fmt) "efi: " fmt + #include #include #include #include #include #include +#include #include @@ -51,6 +54,32 @@ static phys_addr_t efi_to_phys(unsigned long addr) return addr; } +static __initdata unsigned long screen_info_table = EFI_INVALID_TABLE_ADDR; + +static __initdata efi_config_table_type_t arch_tables[] = { + {LINUX_EFI_ARM_SCREEN_INFO_TABLE_GUID, NULL, &screen_info_table}, + {NULL_GUID, NULL, NULL} +}; + +static void __init init_screen_info(void) +{ + struct screen_info *si; + + if (screen_info_table != EFI_INVALID_TABLE_ADDR) { + si = early_memremap_ro(screen_info_table, sizeof(*si)); + if (!si) { + pr_err("Could not map screen_info config table\n"); + return; + } + screen_info = *si; + early_memunmap(si, sizeof(*si)); + + /* dummycon on ARM needs non-zero values for columns/lines */ + screen_info.orig_video_cols = 80; + screen_info.orig_video_lines = 25; + } +} + static int __init uefi_init(void) { efi_char16_t *c16; @@ -108,7 +137,8 @@ static int __init uefi_init(void) goto out; } retval = efi_config_parse_tables(config_tables, efi.systab->nr_tables, - sizeof(efi_config_table_t), NULL); + sizeof(efi_config_table_t), + arch_tables); early_memunmap(config_tables, table_size); out: @@ -223,4 +253,6 @@ void __init efi_init(void) PAGE_ALIGN(params.mmap_size + (params.mmap & ~PAGE_MASK))); } + + init_screen_info(); } -- cgit v1.2.3