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authorLinus Torvalds <torvalds@linux-foundation.org>2022-10-09 18:56:54 +0300
committerLinus Torvalds <torvalds@linux-foundation.org>2022-10-09 18:56:54 +0300
commit0e470763d84dcad27284067647dfb4b1a94dfce0 (patch)
tree34b7ab8b490ce5bb74255c5810357fc6fc819eba /drivers/firmware/efi/libstub/zboot-header.S
parenta6afa4199d3d038fbfdff5511f7523b0e30cb774 (diff)
parentd3549a938b73f203ef522562ae9f2d38aa43d234 (diff)
downloadlinux-0e470763d84dcad27284067647dfb4b1a94dfce0.tar.xz
Merge tag 'efi-next-for-v6.1' of git://git.kernel.org/pub/scm/linux/kernel/git/efi/efi
Pull EFI updates from Ard Biesheuvel: "A bit more going on than usual in the EFI subsystem. The main driver for this has been the introduction of the LoonArch architecture last cycle, which inspired some cleanup and refactoring of the EFI code. Another driver for EFI changes this cycle and in the future is confidential compute. The LoongArch architecture does not use either struct bootparams or DT natively [yet], and so passing information between the EFI stub and the core kernel using either of those is undesirable. And in general, overloading DT has been a source of issues on arm64, so using DT for this on new architectures is a to avoid for the time being (even if we might converge on something DT based for non-x86 architectures in the future). For this reason, in addition to the patch that enables EFI boot for LoongArch, there are a number of refactoring patches applied on top of which separate the DT bits from the generic EFI stub bits. These changes are on a separate topich branch that has been shared with the LoongArch maintainers, who will include it in their pull request as well. This is not ideal, but the best way to manage the conflicts without stalling LoongArch for another cycle. Another development inspired by LoongArch is the newly added support for EFI based decompressors. Instead of adding yet another arch-specific incarnation of this pattern for LoongArch, we are introducing an EFI app based on the existing EFI libstub infrastructure that encapulates the decompression code we use on other architectures, but in a way that is fully generic. This has been developed and tested in collaboration with distro and systemd folks, who are eager to start using this for systemd-boot and also for arm64 secure boot on Fedora. Note that the EFI zimage files this introduces can also be decompressed by non-EFI bootloaders if needed, as the image header describes the location of the payload inside the image, and the type of compression that was used. (Note that Fedora's arm64 GRUB is buggy [0] so you'll need a recent version or switch to systemd-boot in order to use this.) Finally, we are adding TPM measurement of the kernel command line provided by EFI. There is an oversight in the TCG spec which results in a blind spot for command line arguments passed to loaded images, which means that either the loader or the stub needs to take the measurement. Given the combinatorial explosion I am anticipating when it comes to firmware/bootloader stacks and firmware based attestation protocols (SEV-SNP, TDX, DICE, DRTM), it is good to set a baseline now when it comes to EFI measured boot, which is that the kernel measures the initrd and command line. Intermediate loaders can measure additional assets if needed, but with the baseline in place, we can deploy measured boot in a meaningful way even if you boot into Linux straight from the EFI firmware. Summary: - implement EFI boot support for LoongArch - implement generic EFI compressed boot support for arm64, RISC-V and LoongArch, none of which implement a decompressor today - measure the kernel command line into the TPM if measured boot is in effect - refactor the EFI stub code in order to isolate DT dependencies for architectures other than x86 - avoid calling SetVirtualAddressMap() on arm64 if the configured size of the VA space guarantees that doing so is unnecessary - move some ARM specific code out of the generic EFI source files - unmap kernel code from the x86 mixed mode 1:1 page tables" * tag 'efi-next-for-v6.1' of git://git.kernel.org/pub/scm/linux/kernel/git/efi/efi: (24 commits) efi/arm64: libstub: avoid SetVirtualAddressMap() when possible efi: zboot: create MemoryMapped() device path for the parent if needed efi: libstub: fix up the last remaining open coded boot service call efi/arm: libstub: move ARM specific code out of generic routines efi/libstub: measure EFI LoadOptions efi/libstub: refactor the initrd measuring functions efi/loongarch: libstub: remove dependency on flattened DT efi: libstub: install boot-time memory map as config table efi: libstub: remove DT dependency from generic stub efi: libstub: unify initrd loading between architectures efi: libstub: remove pointless goto kludge efi: libstub: simplify efi_get_memory_map() and struct efi_boot_memmap efi: libstub: avoid efi_get_memory_map() for allocating the virt map efi: libstub: drop pointless get_memory_map() call efi: libstub: fix type confusion for load_options_size arm64: efi: enable generic EFI compressed boot loongarch: efi: enable generic EFI compressed boot riscv: efi: enable generic EFI compressed boot efi/libstub: implement generic EFI zboot efi/libstub: move efi_system_table global var into separate object ...
Diffstat (limited to 'drivers/firmware/efi/libstub/zboot-header.S')
-rw-r--r--drivers/firmware/efi/libstub/zboot-header.S143
1 files changed, 143 insertions, 0 deletions
diff --git a/drivers/firmware/efi/libstub/zboot-header.S b/drivers/firmware/efi/libstub/zboot-header.S
new file mode 100644
index 000000000000..9e6fe061ab07
--- /dev/null
+++ b/drivers/firmware/efi/libstub/zboot-header.S
@@ -0,0 +1,143 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+
+#include <linux/pe.h>
+
+#ifdef CONFIG_64BIT
+ .set .Lextra_characteristics, 0x0
+ .set .Lpe_opt_magic, PE_OPT_MAGIC_PE32PLUS
+#else
+ .set .Lextra_characteristics, IMAGE_FILE_32BIT_MACHINE
+ .set .Lpe_opt_magic, PE_OPT_MAGIC_PE32
+#endif
+
+ .section ".head", "a"
+ .globl __efistub_efi_zboot_header
+__efistub_efi_zboot_header:
+.Ldoshdr:
+ .long MZ_MAGIC
+ .ascii "zimg" // image type
+ .long __efistub__gzdata_start - .Ldoshdr // payload offset
+ .long __efistub__gzdata_size - ZBOOT_SIZE_LEN // payload size
+ .long 0, 0 // reserved
+ .asciz COMP_TYPE // compression type
+ .org .Ldoshdr + 0x3c
+ .long .Lpehdr - .Ldoshdr // PE header offset
+
+.Lpehdr:
+ .long PE_MAGIC
+ .short MACHINE_TYPE
+ .short .Lsection_count
+ .long 0
+ .long 0
+ .long 0
+ .short .Lsection_table - .Loptional_header
+ .short IMAGE_FILE_DEBUG_STRIPPED | \
+ IMAGE_FILE_EXECUTABLE_IMAGE | \
+ IMAGE_FILE_LINE_NUMS_STRIPPED |\
+ .Lextra_characteristics
+
+.Loptional_header:
+ .short .Lpe_opt_magic
+ .byte 0, 0
+ .long _etext - .Lefi_header_end
+ .long __data_size
+ .long 0
+ .long __efistub_efi_zboot_entry - .Ldoshdr
+ .long .Lefi_header_end - .Ldoshdr
+
+#ifdef CONFIG_64BIT
+ .quad 0
+#else
+ .long _etext - .Ldoshdr, 0x0
+#endif
+ .long 4096
+ .long 512
+ .short 0, 0
+ .short LINUX_EFISTUB_MAJOR_VERSION // MajorImageVersion
+ .short LINUX_EFISTUB_MINOR_VERSION // MinorImageVersion
+ .short 0, 0
+ .long 0
+ .long _end - .Ldoshdr
+
+ .long .Lefi_header_end - .Ldoshdr
+ .long 0
+ .short IMAGE_SUBSYSTEM_EFI_APPLICATION
+ .short 0
+#ifdef CONFIG_64BIT
+ .quad 0, 0, 0, 0
+#else
+ .long 0, 0, 0, 0
+#endif
+ .long 0
+ .long (.Lsection_table - .) / 8
+
+ .quad 0 // ExportTable
+ .quad 0 // ImportTable
+ .quad 0 // ResourceTable
+ .quad 0 // ExceptionTable
+ .quad 0 // CertificationTable
+ .quad 0 // BaseRelocationTable
+#ifdef CONFIG_DEBUG_EFI
+ .long .Lefi_debug_table - .Ldoshdr // DebugTable
+ .long .Lefi_debug_table_size
+#endif
+
+.Lsection_table:
+ .ascii ".text\0\0\0"
+ .long _etext - .Lefi_header_end
+ .long .Lefi_header_end - .Ldoshdr
+ .long _etext - .Lefi_header_end
+ .long .Lefi_header_end - .Ldoshdr
+
+ .long 0, 0
+ .short 0, 0
+ .long IMAGE_SCN_CNT_CODE | \
+ IMAGE_SCN_MEM_READ | \
+ IMAGE_SCN_MEM_EXECUTE
+
+ .ascii ".data\0\0\0"
+ .long __data_size
+ .long _etext - .Ldoshdr
+ .long __data_rawsize
+ .long _etext - .Ldoshdr
+
+ .long 0, 0
+ .short 0, 0
+ .long IMAGE_SCN_CNT_INITIALIZED_DATA | \
+ IMAGE_SCN_MEM_READ | \
+ IMAGE_SCN_MEM_WRITE
+
+ .set .Lsection_count, (. - .Lsection_table) / 40
+
+#ifdef CONFIG_DEBUG_EFI
+ .section ".rodata", "a"
+ .align 2
+.Lefi_debug_table:
+ // EFI_IMAGE_DEBUG_DIRECTORY_ENTRY
+ .long 0 // Characteristics
+ .long 0 // TimeDateStamp
+ .short 0 // MajorVersion
+ .short 0 // MinorVersion
+ .long IMAGE_DEBUG_TYPE_CODEVIEW // Type
+ .long .Lefi_debug_entry_size // SizeOfData
+ .long 0 // RVA
+ .long .Lefi_debug_entry - .Ldoshdr // FileOffset
+
+ .set .Lefi_debug_table_size, . - .Lefi_debug_table
+ .previous
+
+.Lefi_debug_entry:
+ // EFI_IMAGE_DEBUG_CODEVIEW_NB10_ENTRY
+ .ascii "NB10" // Signature
+ .long 0 // Unknown
+ .long 0 // Unknown2
+ .long 0 // Unknown3
+
+ .asciz ZBOOT_EFI_PATH
+
+ .set .Lefi_debug_entry_size, . - .Lefi_debug_entry
+#endif
+
+ .p2align 12
+.Lefi_header_end:
+