From: Matt Fleming <matt.fleming@xxxxxxxxx> This patch series enables booting a 64-bit kernel on 32-bit EFI firmware. It's marked as RFC because I'm just after some general feedback on the approach taken. Note that no boot loader changes should be necessary to take advantage of these patches. Tested Qemu + OVMF with Syslinux. Some things that I'm going to fix up meanwhile are, o failure for > 4GB arg ptrs to EFI services should be graceful o revisit whether it's OK to mark the identity-mapped kernel text as executable. o I'm pretty sure these patches break 32-bit boot completely o The ARM EFI stub doesn't handle relocations so can't jump through global function pointers The full series is available on the 'mixed-mode' branch here, git://git.kernel.org/pub/scm/linux/kernel/git/mfleming/efi.git Matt Fleming (11): x86/boot: Cleanup header.S by removing some #ifdefs x86, tools: Consolidate #ifdef code x86/mm/pageattr: Make __lookup_address_in_pgd() global x86/efi: Delete dead code when checking for non-native efi: Add separate 32-bit/64-bit definitions x86/efi: Build our own EFI services pointer table x86/efi: Add early thunk code to go from 64-bit to 32-bit x86/efi: Split the boot stub into 32/64 code paths x86/efi: Firmware agnostic handover entry points x86/efi: Add mixed runtime services support x86/efi: Wire up CONFIG_EFI_MIXED arch/x86/Kconfig | 10 + arch/x86/boot/Makefile | 2 +- arch/x86/boot/compressed/eboot.c | 669 +++++++++++++++++++++++++++------ arch/x86/boot/compressed/eboot.h | 60 +++ arch/x86/boot/compressed/efi_stub_64.S | 29 ++ arch/x86/boot/compressed/head_64.S | 123 +++++- arch/x86/boot/header.S | 23 +- arch/x86/boot/tools/build.c | 73 ++-- arch/x86/include/asm/efi.h | 38 +- arch/x86/include/asm/pgtable_types.h | 2 + arch/x86/kernel/setup.c | 2 +- arch/x86/mm/fault.c | 7 +- arch/x86/mm/pageattr.c | 12 +- arch/x86/platform/efi/Makefile | 1 + arch/x86/platform/efi/efi.c | 154 ++++---- arch/x86/platform/efi/efi_64.c | 328 +++++++++++++++- arch/x86/platform/efi/efi_stub_64.S | 161 ++++++++ arch/x86/platform/efi/efi_thunk.S | 65 ++++ drivers/firmware/efi/efi-stub-helper.c | 142 ++----- include/linux/efi.h | 252 +++++++++++++ 20 files changed, 1807 insertions(+), 346 deletions(-) create mode 100644 arch/x86/platform/efi/efi_thunk.S -- 1.8.3.1 -- To unsubscribe from this list: send the line "unsubscribe linux-efi" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
