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path: root/drivers/firmware/efi/libstub/efi-stub-helper.c
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2015-01-20efi/libstub: Call get_memory_map() to obtain map and desc sizesArd Biesheuvel
This fixes two minor issues in the implementation of get_memory_map(): - Currently, it assumes that sizeof(efi_memory_desc_t) == desc_size, which is usually true, but not mandated by the spec. (This was added intentionally to allow future additions to the definition of efi_memory_desc_t). The way the loop is implemented currently, the added slack space may be insufficient if desc_size is larger, which in some corner cases could result in the loop never terminating. - It allocates 32 efi_memory_desc_t entries first (again, using the size of the struct instead of desc_size), and frees and reallocates if it turns out to be insufficient. Few implementations of UEFI have such small memory maps, which results in a unnecessary allocate/free pair on each invocation. Fix this by calling the get_memory_map() boot service first with a '0' input value for map size to retrieve the map size and desc size from the firmware and only then perform the allocation, using desc_size rather than sizeof(efi_memory_desc_t). Signed-off-by: Ard Biesheuvel <ard.biesheuvel@linaro.org> Signed-off-by: Matt Fleming <matt.fleming@intel.com>
2015-01-15arm64/efi: efistub: Apply __init annotationArd Biesheuvel
This ensures all stub component are freed when the kernel proper is done booting, by prefixing the names of all ELF sections that have the SHF_ALLOC attribute with ".init". This approach ensures that even implicitly emitted allocated data (like initializer values and string literals) are covered. At the same time, remove some __init annotations in the stub that have now become redundant, and add the __init annotation to handle_kernel_image which will now trigger a section mismatch warning without it. Signed-off-by: Ard Biesheuvel <ard.biesheuvel@linaro.org> Signed-off-by: Matt Fleming <matt.fleming@intel.com>
2015-01-12efi: efistub: allow allocation alignment larger than EFI_PAGE_SIZEArd Biesheuvel
On systems with 64 KB pages, it is preferable for UEFI memory map entries to be 64 KB aligned multiples of 64 KB, because it relieves us of having to deal with the residues. So, if EFI_ALLOC_ALIGN is #define'd by the platform, use it to round up all memory allocations made. Acked-by: Matt Fleming <matt.fleming@intel.com> Acked-by: Borislav Petkov <bp@suse.de> Tested-by: Leif Lindholm <leif.lindholm@linaro.org> Signed-off-by: Ard Biesheuvel <ard.biesheuvel@linaro.org>
2014-10-03efi: Add efi= parameter parsing to the EFI boot stubMatt Fleming
We need a way to customize the behaviour of the EFI boot stub, in particular, we need a way to disable the "chunking" workaround, used when reading files from the EFI System Partition. One of my machines doesn't cope well when reading files in 1MB chunks to a buffer above the 4GB mark - it appears that the "chunking" bug workaround triggers another firmware bug. This was only discovered with commit 4bf7111f5016 ("x86/efi: Support initrd loaded above 4G"), and that commit is perfectly valid. The symptom I observed was a corrupt initrd rather than any kind of crash. efi= is now used to specify EFI parameters in two very different execution environments, the EFI boot stub and during kernel boot. There is also a slight performance optimization by enabling efi=nochunk, but that's offset by the fact that you're more likely to run into firmware issues, at least on x86. This is the rationale behind leaving the workaround enabled by default. Also provide some documentation for EFI_READ_CHUNK_SIZE and why we're using the current value of 1MB. Tested-by: Ard Biesheuvel <ard.biesheuvel@linaro.org> Cc: Roy Franz <roy.franz@linaro.org> Cc: Maarten Lankhorst <m.b.lankhorst@gmail.com> Cc: Leif Lindholm <leif.lindholm@linaro.org> Cc: Borislav Petkov <bp@suse.de> Signed-off-by: Matt Fleming <matt.fleming@intel.com>
2014-07-18efi: efistub: Convert into static libraryArd Biesheuvel
This patch changes both x86 and arm64 efistub implementations from #including shared .c files under drivers/firmware/efi to building shared code as a static library. The x86 code uses a stub built into the boot executable which uncompresses the kernel at boot time. In this case, the library is linked into the decompressor. In the arm64 case, the stub is part of the kernel proper so the library is linked into the kernel proper as well. Signed-off-by: Ard Biesheuvel <ard.biesheuvel@linaro.org> Signed-off-by: Matt Fleming <matt.fleming@intel.com>