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authorLinus Torvalds <torvalds@linux-foundation.org>2016-03-20 18:58:18 -0700
committerLinus Torvalds <torvalds@linux-foundation.org>2016-03-20 18:58:18 -0700
commit24b5e20f11a75866bbffc46c30a22fa50612a769 (patch)
tree2dab5fc6714a5ad1e31bdea1e954fbd69704ce72 /Documentation
parent26660a4046b171a752e72a1dd32153230234fe3a (diff)
parentd367cef0a7f0c6ee86e997c0cb455b21b3c6b9ba (diff)
Merge branch 'efi-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
Pull EFI updates from Ingo Molnar: "The main changes are: - Use separate EFI page tables when executing EFI firmware code. This isolates the EFI context from the rest of the kernel, which has security and general robustness advantages. (Matt Fleming) - Run regular UEFI firmware with interrupts enabled. This is already the status quo under other OSs. (Ard Biesheuvel) - Various x86 EFI enhancements, such as the use of non-executable attributes for EFI memory mappings. (Sai Praneeth Prakhya) - Various arm64 UEFI enhancements. (Ard Biesheuvel) - ... various fixes and cleanups. The separate EFI page tables feature got delayed twice already, because it's an intrusive change and we didn't feel confident about it - third time's the charm we hope!" * 'efi-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (37 commits) x86/mm/pat: Fix boot crash when 1GB pages are not supported by the CPU x86/efi: Only map kernel text for EFI mixed mode x86/efi: Map EFI_MEMORY_{XP,RO} memory region bits to EFI page tables x86/mm/pat: Don't implicitly allow _PAGE_RW in kernel_map_pages_in_pgd() efi/arm*: Perform hardware compatibility check efi/arm64: Check for h/w support before booting a >4 KB granular kernel efi/arm: Check for LPAE support before booting a LPAE kernel efi/arm-init: Use read-only early mappings efi/efistub: Prevent __init annotations from being used arm64/vmlinux.lds.S: Handle .init.rodata.xxx and .init.bss sections efi/arm64: Drop __init annotation from handle_kernel_image() x86/mm/pat: Use _PAGE_GLOBAL bit for EFI page table mappings efi/runtime-wrappers: Run UEFI Runtime Services with interrupts enabled efi: Reformat GUID tables to follow the format in UEFI spec efi: Add Persistent Memory type name efi: Add NV memory attribute x86/efi: Show actual ending addresses in efi_print_memmap x86/efi/bgrt: Don't ignore the BGRT if the 'valid' bit is 0 efivars: Use to_efivar_entry efi: Runtime-wrapper: Get rid of the rtc_lock spinlock ...
Diffstat (limited to 'Documentation')
-rw-r--r--Documentation/efi-stub.txt4
-rw-r--r--Documentation/x86/x86_64/mm.txt12
2 files changed, 8 insertions, 8 deletions
diff --git a/Documentation/efi-stub.txt b/Documentation/efi-stub.txt
index 7747024d3bb7..e15746988261 100644
--- a/Documentation/efi-stub.txt
+++ b/Documentation/efi-stub.txt
@@ -10,12 +10,12 @@ arch/x86/boot/header.S and arch/x86/boot/compressed/eboot.c,
respectively. For ARM the EFI stub is implemented in
arch/arm/boot/compressed/efi-header.S and
arch/arm/boot/compressed/efi-stub.c. EFI stub code that is shared
-between architectures is in drivers/firmware/efi/efi-stub-helper.c.
+between architectures is in drivers/firmware/efi/libstub.
For arm64, there is no compressed kernel support, so the Image itself
masquerades as a PE/COFF image and the EFI stub is linked into the
kernel. The arm64 EFI stub lives in arch/arm64/kernel/efi-entry.S
-and arch/arm64/kernel/efi-stub.c.
+and drivers/firmware/efi/libstub/arm64-stub.c.
By using the EFI boot stub it's possible to boot a Linux kernel
without the use of a conventional EFI boot loader, such as grub or
diff --git a/Documentation/x86/x86_64/mm.txt b/Documentation/x86/x86_64/mm.txt
index 05712ac83e38..c518dce7da4d 100644
--- a/Documentation/x86/x86_64/mm.txt
+++ b/Documentation/x86/x86_64/mm.txt
@@ -16,6 +16,8 @@ ffffec0000000000 - fffffc0000000000 (=44 bits) kasan shadow memory (16TB)
... unused hole ...
ffffff0000000000 - ffffff7fffffffff (=39 bits) %esp fixup stacks
... unused hole ...
+ffffffef00000000 - ffffffff00000000 (=64 GB) EFI region mapping space
+... unused hole ...
ffffffff80000000 - ffffffffa0000000 (=512 MB) kernel text mapping, from phys 0
ffffffffa0000000 - ffffffffff5fffff (=1525 MB) module mapping space
ffffffffff600000 - ffffffffffdfffff (=8 MB) vsyscalls
@@ -32,11 +34,9 @@ reference.
Current X86-64 implementations only support 40 bits of address space,
but we support up to 46 bits. This expands into MBZ space in the page tables.
-->trampoline_pgd:
-
-We map EFI runtime services in the aforementioned PGD in the virtual
-range of 64Gb (arbitrarily set, can be raised if needed)
-
-0xffffffef00000000 - 0xffffffff00000000
+We map EFI runtime services in the 'efi_pgd' PGD in a 64Gb large virtual
+memory window (this size is arbitrary, it can be raised later if needed).
+The mappings are not part of any other kernel PGD and are only available
+during EFI runtime calls.
-Andi Kleen, Jul 2004