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efi: Fix the ACPI BGRT driver for images located in EFI boot services memory

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The ACPI BGRT driver accesses the BIOS logo image when it initializes.
However, ACPI 5.0 (which introduces the BGRT) recommends putting the
logo image in EFI boot services memory, so that the OS can reclaim that
memory.  Production systems follow this recommendation, breaking the
ACPI BGRT driver.

Move the bulk of the BGRT code to run during a new EFI late
initialization phase, which occurs after switching EFI to virtual mode,
and after initializing ACPI, but before freeing boot services memory.
Copy the BIOS logo image to kernel memory at that point, and make it
accessible to the BGRT driver.  Rework the existing ACPI BGRT driver to
act as a simple wrapper exposing that image (and the properties from the
BGRT) via sysfs.

Signed-off-by: Josh Triplett <josh@joshtriplett.org>
Link: http://lkml.kernel.org/r/93ce9f823f1c1f3bb88bdd662cce08eee7a17f5d.1348876882.git.josh@joshtriplett.org
Signed-off-by: H. Peter Anvin <hpa@linux.intel.com>
This commit is contained in:
Josh Triplett
2012-09-28 17:57:05 -07:00
committed by H. Peter Anvin
parent 7bc90e01c3
commit 2223af3890
8 changed files with 120 additions and 70 deletions
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2
include/linux/efi.h
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@@ -497,8 +497,10 @@ extern void efi_memmap_walk (efi_freemem_callback_t callback, void *arg);
extern void efi_gettimeofday (struct timespec *ts);
extern void efi_enter_virtual_mode (void); /* switch EFI to virtual mode, if possible */
#ifdef CONFIG_X86
extern void efi_late_init(void);
extern void efi_free_boot_services(void);
#else
static inline void efi_late_init(void) {}
static inline void efi_free_boot_services(void) {}
#endif
extern void __iomem *efi_lookup_mapped_addr(u64 phys_addr);