| lists.openwall.net | lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC | |
|
Open Source and information security mailing list archives
| ||
|
Message-ID: <8bc0a2a5-a486-4a4d-83e6-45b6c00685ea@amd.com> Date: Mon, 7 Apr 2025 15:11:32 +0530 From: "Aithal, Srikanth" <sraithal@....com> To: Ard Biesheuvel <ardb@...nel.org> Cc: linux-kernel@...r.kernel.org, Ingo Molnar <mingo@...nel.org>, David Woodhouse <dwmw@...zon.co.uk>, "H. Peter Anvin" <hpa@...or.com>, Kees Cook <keescook@...omium.org>, x86@...nel.org Subject: Re: [tip: x86/boot] x86/boot: Move the EFI mixed mode startup code back under arch/x86, into startup/ On 4/7/2025 2:00 PM, Ard Biesheuvel wrote: > On Mon, 7 Apr 2025 at 10:38, Aithal, Srikanth <sraithal@....com> wrote: >> >> Hello, >> >> This commit breaks the build of next-20250407. The kernel config is >> attached here. >> >> Build error: >> >> arch/x86/boot/startup/efi-mixed.o: warning: objtool: >> efi32_stub_entry+0x0: unannotated intra-function call >> make[3]: *** [scripts/Makefile.build:335: >> arch/x86/boot/startup/efi-mixed.o] Error 255 >> make[3]: *** Deleting file 'arch/x86/boot/startup/efi-mixed.o' >> make[3]: *** Waiting for unfinished jobs.... >> make[2]: *** [scripts/Makefile.build:461: arch/x86/boot/startup] Error 2 >> make[2]: *** Waiting for unfinished jobs.... >> make[1]: *** [/home/VT_BUILD/linux/Makefile:2006: .] Error 2 >> make: *** [Makefile:248: __sub-make] Error 2 >> >> > > Apologies for the breakage. > > Does it help to add the following to arch/x86/boot/startup/Makefile: > > OBJECT_FILES_NON_STANDARD := y > > ? yes, this fixes the issue. Reported-by: Srikanth Aithal <sraithal@....com> Tested-by: Srikanth Aithal <sraithal@....com> > >> >> Thanks, >> Srikanth Aithal <sraithal@....com> >> >> >> On 4/7/2025 12:03 AM, tip-bot2 for Ard Biesheuvel wrote: >>> The following commit has been merged into the x86/boot branch of tip: >>> >>> Commit-ID: 4f2d1bbc2c92a32fd612e6c3b51832d5c1c3678e >>> Gitweb: https://git.kernel.org/tip/4f2d1bbc2c92a32fd612e6c3b51832d5c1c3678e >>> Author: Ard Biesheuvel <ardb@...nel.org> >>> AuthorDate: Tue, 01 Apr 2025 15:34:20 +02:00 >>> Committer: Ingo Molnar <mingo@...nel.org> >>> CommitterDate: Sun, 06 Apr 2025 20:15:14 +02:00 >>> >>> x86/boot: Move the EFI mixed mode startup code back under arch/x86, into startup/ >>> >>> Linus expressed a strong preference for arch-specific asm code (i.e., >>> virtually all of it) to reside under arch/ rather than anywhere else. >>> >>> So move the EFI mixed mode startup code back, and put it under >>> arch/x86/boot/startup/ where all shared x86 startup code is going to >>> live. >>> >>> Suggested-by: Linus Torvalds <torvalds@...ux-foundation.org> >>> Signed-off-by: Ard Biesheuvel <ardb@...nel.org> >>> Signed-off-by: Ingo Molnar <mingo@...nel.org> >>> Cc: David Woodhouse <dwmw@...zon.co.uk> >>> Cc: H. Peter Anvin <hpa@...or.com> >>> Cc: Kees Cook <keescook@...omium.org> >>> Link: https://lore.kernel.org/r/20250401133416.1436741-11-ardb+git@google.com >>> --- >>> arch/x86/boot/startup/Makefile | 3 +- >>> arch/x86/boot/startup/efi-mixed.S | 253 ++++++++++++++++++++++- >>> drivers/firmware/efi/libstub/Makefile | 1 +- >>> drivers/firmware/efi/libstub/x86-mixed.S | 253 +---------------------- >>> 4 files changed, 256 insertions(+), 254 deletions(-) >>> create mode 100644 arch/x86/boot/startup/efi-mixed.S >>> delete mode 100644 drivers/firmware/efi/libstub/x86-mixed.S >>> >>> diff --git a/arch/x86/boot/startup/Makefile b/arch/x86/boot/startup/Makefile >>> index 03519ef..73946a3 100644 >>> --- a/arch/x86/boot/startup/Makefile >>> +++ b/arch/x86/boot/startup/Makefile >>> @@ -1,3 +1,6 @@ >>> # SPDX-License-Identifier: GPL-2.0 >>> >>> +KBUILD_AFLAGS += -D__DISABLE_EXPORTS >>> + >>> lib-$(CONFIG_X86_64) += la57toggle.o >>> +lib-$(CONFIG_EFI_MIXED) += efi-mixed.o >>> diff --git a/arch/x86/boot/startup/efi-mixed.S b/arch/x86/boot/startup/efi-mixed.S >>> new file mode 100644 >>> index 0000000..e04ed99 >>> --- /dev/null >>> +++ b/arch/x86/boot/startup/efi-mixed.S >>> @@ -0,0 +1,253 @@ >>> +/* SPDX-License-Identifier: GPL-2.0 */ >>> +/* >>> + * Copyright (C) 2014, 2015 Intel Corporation; author Matt Fleming >>> + * >>> + * Early support for invoking 32-bit EFI services from a 64-bit kernel. >>> + * >>> + * Because this thunking occurs before ExitBootServices() we have to >>> + * restore the firmware's 32-bit GDT and IDT before we make EFI service >>> + * calls. >>> + * >>> + * On the plus side, we don't have to worry about mangling 64-bit >>> + * addresses into 32-bits because we're executing with an identity >>> + * mapped pagetable and haven't transitioned to 64-bit virtual addresses >>> + * yet. >>> + */ >>> + >>> +#include <linux/linkage.h> >>> +#include <asm/desc_defs.h> >>> +#include <asm/msr.h> >>> +#include <asm/page_types.h> >>> +#include <asm/pgtable_types.h> >>> +#include <asm/processor-flags.h> >>> +#include <asm/segment.h> >>> + >>> + .text >>> + .code32 >>> +#ifdef CONFIG_EFI_HANDOVER_PROTOCOL >>> +SYM_FUNC_START(efi32_stub_entry) >>> + call 1f >>> +1: popl %ecx >>> + >>> + /* Clear BSS */ >>> + xorl %eax, %eax >>> + leal (_bss - 1b)(%ecx), %edi >>> + leal (_ebss - 1b)(%ecx), %ecx >>> + subl %edi, %ecx >>> + shrl $2, %ecx >>> + cld >>> + rep stosl >>> + >>> + add $0x4, %esp /* Discard return address */ >>> + movl 8(%esp), %ebx /* struct boot_params pointer */ >>> + jmp efi32_startup >>> +SYM_FUNC_END(efi32_stub_entry) >>> +#endif >>> + >>> +/* >>> + * Called using a far call from __efi64_thunk() below, using the x86_64 SysV >>> + * ABI (except for R8/R9 which are inaccessible to 32-bit code - EAX/EBX are >>> + * used instead). EBP+16 points to the arguments passed via the stack. >>> + * >>> + * The first argument (EDI) is a pointer to the boot service or protocol, to >>> + * which the remaining arguments are passed, each truncated to 32 bits. >>> + */ >>> +SYM_FUNC_START_LOCAL(efi_enter32) >>> + /* >>> + * Convert x86-64 SysV ABI params to i386 ABI >>> + */ >>> + pushl 32(%ebp) /* Up to 3 args passed via the stack */ >>> + pushl 24(%ebp) >>> + pushl 16(%ebp) >>> + pushl %ebx /* R9 */ >>> + pushl %eax /* R8 */ >>> + pushl %ecx >>> + pushl %edx >>> + pushl %esi >>> + >>> + /* Disable paging */ >>> + movl %cr0, %eax >>> + btrl $X86_CR0_PG_BIT, %eax >>> + movl %eax, %cr0 >>> + >>> + /* Disable long mode via EFER */ >>> + movl $MSR_EFER, %ecx >>> + rdmsr >>> + btrl $_EFER_LME, %eax >>> + wrmsr >>> + >>> + call *%edi >>> + >>> + /* We must preserve return value */ >>> + movl %eax, %edi >>> + >>> + call efi32_enable_long_mode >>> + >>> + addl $32, %esp >>> + movl %edi, %eax >>> + lret >>> +SYM_FUNC_END(efi_enter32) >>> + >>> + .code64 >>> +SYM_FUNC_START(__efi64_thunk) >>> + push %rbp >>> + movl %esp, %ebp >>> + push %rbx >>> + >>> + /* Move args #5 and #6 into 32-bit accessible registers */ >>> + movl %r8d, %eax >>> + movl %r9d, %ebx >>> + >>> + lcalll *efi32_call(%rip) >>> + >>> + pop %rbx >>> + pop %rbp >>> + RET >>> +SYM_FUNC_END(__efi64_thunk) >>> + >>> + .code32 >>> +SYM_FUNC_START_LOCAL(efi32_enable_long_mode) >>> + movl %cr4, %eax >>> + btsl $(X86_CR4_PAE_BIT), %eax >>> + movl %eax, %cr4 >>> + >>> + movl $MSR_EFER, %ecx >>> + rdmsr >>> + btsl $_EFER_LME, %eax >>> + wrmsr >>> + >>> + /* Disable interrupts - the firmware's IDT does not work in long mode */ >>> + cli >>> + >>> + /* Enable paging */ >>> + movl %cr0, %eax >>> + btsl $X86_CR0_PG_BIT, %eax >>> + movl %eax, %cr0 >>> + ret >>> +SYM_FUNC_END(efi32_enable_long_mode) >>> + >>> +/* >>> + * This is the common EFI stub entry point for mixed mode. It sets up the GDT >>> + * and page tables needed for 64-bit execution, after which it calls the >>> + * common 64-bit EFI entrypoint efi_stub_entry(). >>> + * >>> + * Arguments: 0(%esp) image handle >>> + * 4(%esp) EFI system table pointer >>> + * %ebx struct boot_params pointer (or NULL) >>> + * >>> + * Since this is the point of no return for ordinary execution, no registers >>> + * are considered live except for the function parameters. [Note that the EFI >>> + * stub may still exit and return to the firmware using the Exit() EFI boot >>> + * service.] >>> + */ >>> +SYM_FUNC_START_LOCAL(efi32_startup) >>> + movl %esp, %ebp >>> + >>> + subl $8, %esp >>> + sgdtl (%esp) /* Save GDT descriptor to the stack */ >>> + movl 2(%esp), %esi /* Existing GDT pointer */ >>> + movzwl (%esp), %ecx /* Existing GDT limit */ >>> + inc %ecx /* Existing GDT size */ >>> + andl $~7, %ecx /* Ensure size is multiple of 8 */ >>> + >>> + subl %ecx, %esp /* Allocate new GDT */ >>> + andl $~15, %esp /* Realign the stack */ >>> + movl %esp, %edi /* New GDT address */ >>> + leal 7(%ecx), %eax /* New GDT limit */ >>> + pushw %cx /* Push 64-bit CS (for LJMP below) */ >>> + pushl %edi /* Push new GDT address */ >>> + pushw %ax /* Push new GDT limit */ >>> + >>> + /* Copy GDT to the stack and add a 64-bit code segment at the end */ >>> + movl $GDT_ENTRY(DESC_CODE64, 0, 0xfffff) & 0xffffffff, (%edi,%ecx) >>> + movl $GDT_ENTRY(DESC_CODE64, 0, 0xfffff) >> 32, 4(%edi,%ecx) >>> + shrl $2, %ecx >>> + cld >>> + rep movsl /* Copy the firmware GDT */ >>> + lgdtl (%esp) /* Switch to the new GDT */ >>> + >>> + call 1f >>> +1: pop %edi >>> + >>> + /* Record mixed mode entry */ >>> + movb $0x0, (efi_is64 - 1b)(%edi) >>> + >>> + /* Set up indirect far call to re-enter 32-bit mode */ >>> + leal (efi32_call - 1b)(%edi), %eax >>> + addl %eax, (%eax) >>> + movw %cs, 4(%eax) >>> + >>> + /* Disable paging */ >>> + movl %cr0, %eax >>> + btrl $X86_CR0_PG_BIT, %eax >>> + movl %eax, %cr0 >>> + >>> + /* Set up 1:1 mapping */ >>> + leal (pte - 1b)(%edi), %eax >>> + movl $_PAGE_PRESENT | _PAGE_RW | _PAGE_PSE, %ecx >>> + leal (_PAGE_PRESENT | _PAGE_RW)(%eax), %edx >>> +2: movl %ecx, (%eax) >>> + addl $8, %eax >>> + addl $PMD_SIZE, %ecx >>> + jnc 2b >>> + >>> + movl $PAGE_SIZE, %ecx >>> + .irpc l, 0123 >>> + movl %edx, \l * 8(%eax) >>> + addl %ecx, %edx >>> + .endr >>> + addl %ecx, %eax >>> + movl %edx, (%eax) >>> + movl %eax, %cr3 >>> + >>> + call efi32_enable_long_mode >>> + >>> + /* Set up far jump to 64-bit mode (CS is already on the stack) */ >>> + leal (efi_stub_entry - 1b)(%edi), %eax >>> + movl %eax, 2(%esp) >>> + >>> + movl 0(%ebp), %edi >>> + movl 4(%ebp), %esi >>> + movl %ebx, %edx >>> + ljmpl *2(%esp) >>> +SYM_FUNC_END(efi32_startup) >>> + >>> +/* >>> + * efi_status_t efi32_pe_entry(efi_handle_t image_handle, >>> + * efi_system_table_32_t *sys_table) >>> + */ >>> +SYM_FUNC_START(efi32_pe_entry) >>> + pushl %ebx // save callee-save registers >>> + >>> + /* Check whether the CPU supports long mode */ >>> + movl $0x80000001, %eax // assume extended info support >>> + cpuid >>> + btl $29, %edx // check long mode bit >>> + jnc 1f >>> + leal 8(%esp), %esp // preserve stack alignment >>> + xor %ebx, %ebx // no struct boot_params pointer >>> + jmp efi32_startup // only ESP and EBX remain live >>> +1: movl $0x80000003, %eax // EFI_UNSUPPORTED >>> + popl %ebx >>> + RET >>> +SYM_FUNC_END(efi32_pe_entry) >>> + >>> +#ifdef CONFIG_EFI_HANDOVER_PROTOCOL >>> + .org efi32_stub_entry + 0x200 >>> + .code64 >>> +SYM_FUNC_START_NOALIGN(efi64_stub_entry) >>> + jmp efi_handover_entry >>> +SYM_FUNC_END(efi64_stub_entry) >>> +#endif >>> + >>> + .data >>> + .balign 8 >>> +SYM_DATA_START_LOCAL(efi32_call) >>> + .long efi_enter32 - . >>> + .word 0x0 >>> +SYM_DATA_END(efi32_call) >>> +SYM_DATA(efi_is64, .byte 1) >>> + >>> + .bss >>> + .balign PAGE_SIZE >>> +SYM_DATA_LOCAL(pte, .fill 6 * PAGE_SIZE, 1, 0) >>> diff --git a/drivers/firmware/efi/libstub/Makefile b/drivers/firmware/efi/libstub/Makefile >>> index d23a1b9..2f17339 100644 >>> --- a/drivers/firmware/efi/libstub/Makefile >>> +++ b/drivers/firmware/efi/libstub/Makefile >>> @@ -85,7 +85,6 @@ lib-$(CONFIG_EFI_GENERIC_STUB) += efi-stub.o string.o intrinsics.o systable.o \ >>> lib-$(CONFIG_ARM) += arm32-stub.o >>> lib-$(CONFIG_ARM64) += kaslr.o arm64.o arm64-stub.o smbios.o >>> lib-$(CONFIG_X86) += x86-stub.o smbios.o >>> -lib-$(CONFIG_EFI_MIXED) += x86-mixed.o >>> lib-$(CONFIG_X86_64) += x86-5lvl.o >>> lib-$(CONFIG_RISCV) += kaslr.o riscv.o riscv-stub.o >>> lib-$(CONFIG_LOONGARCH) += loongarch.o loongarch-stub.o >>> diff --git a/drivers/firmware/efi/libstub/x86-mixed.S b/drivers/firmware/efi/libstub/x86-mixed.S >>> deleted file mode 100644 >>> index e04ed99..0000000 >>> --- a/drivers/firmware/efi/libstub/x86-mixed.S >>> +++ /dev/null >>> @@ -1,253 +0,0 @@ >>> -/* SPDX-License-Identifier: GPL-2.0 */ >>> -/* >>> - * Copyright (C) 2014, 2015 Intel Corporation; author Matt Fleming >>> - * >>> - * Early support for invoking 32-bit EFI services from a 64-bit kernel. >>> - * >>> - * Because this thunking occurs before ExitBootServices() we have to >>> - * restore the firmware's 32-bit GDT and IDT before we make EFI service >>> - * calls. >>> - * >>> - * On the plus side, we don't have to worry about mangling 64-bit >>> - * addresses into 32-bits because we're executing with an identity >>> - * mapped pagetable and haven't transitioned to 64-bit virtual addresses >>> - * yet. >>> - */ >>> - >>> -#include <linux/linkage.h> >>> -#include <asm/desc_defs.h> >>> -#include <asm/msr.h> >>> -#include <asm/page_types.h> >>> -#include <asm/pgtable_types.h> >>> -#include <asm/processor-flags.h> >>> -#include <asm/segment.h> >>> - >>> - .text >>> - .code32 >>> -#ifdef CONFIG_EFI_HANDOVER_PROTOCOL >>> -SYM_FUNC_START(efi32_stub_entry) >>> - call 1f >>> -1: popl %ecx >>> - >>> - /* Clear BSS */ >>> - xorl %eax, %eax >>> - leal (_bss - 1b)(%ecx), %edi >>> - leal (_ebss - 1b)(%ecx), %ecx >>> - subl %edi, %ecx >>> - shrl $2, %ecx >>> - cld >>> - rep stosl >>> - >>> - add $0x4, %esp /* Discard return address */ >>> - movl 8(%esp), %ebx /* struct boot_params pointer */ >>> - jmp efi32_startup >>> -SYM_FUNC_END(efi32_stub_entry) >>> -#endif >>> - >>> -/* >>> - * Called using a far call from __efi64_thunk() below, using the x86_64 SysV >>> - * ABI (except for R8/R9 which are inaccessible to 32-bit code - EAX/EBX are >>> - * used instead). EBP+16 points to the arguments passed via the stack. >>> - * >>> - * The first argument (EDI) is a pointer to the boot service or protocol, to >>> - * which the remaining arguments are passed, each truncated to 32 bits. >>> - */ >>> -SYM_FUNC_START_LOCAL(efi_enter32) >>> - /* >>> - * Convert x86-64 SysV ABI params to i386 ABI >>> - */ >>> - pushl 32(%ebp) /* Up to 3 args passed via the stack */ >>> - pushl 24(%ebp) >>> - pushl 16(%ebp) >>> - pushl %ebx /* R9 */ >>> - pushl %eax /* R8 */ >>> - pushl %ecx >>> - pushl %edx >>> - pushl %esi >>> - >>> - /* Disable paging */ >>> - movl %cr0, %eax >>> - btrl $X86_CR0_PG_BIT, %eax >>> - movl %eax, %cr0 >>> - >>> - /* Disable long mode via EFER */ >>> - movl $MSR_EFER, %ecx >>> - rdmsr >>> - btrl $_EFER_LME, %eax >>> - wrmsr >>> - >>> - call *%edi >>> - >>> - /* We must preserve return value */ >>> - movl %eax, %edi >>> - >>> - call efi32_enable_long_mode >>> - >>> - addl $32, %esp >>> - movl %edi, %eax >>> - lret >>> -SYM_FUNC_END(efi_enter32) >>> - >>> - .code64 >>> -SYM_FUNC_START(__efi64_thunk) >>> - push %rbp >>> - movl %esp, %ebp >>> - push %rbx >>> - >>> - /* Move args #5 and #6 into 32-bit accessible registers */ >>> - movl %r8d, %eax >>> - movl %r9d, %ebx >>> - >>> - lcalll *efi32_call(%rip) >>> - >>> - pop %rbx >>> - pop %rbp >>> - RET >>> -SYM_FUNC_END(__efi64_thunk) >>> - >>> - .code32 >>> -SYM_FUNC_START_LOCAL(efi32_enable_long_mode) >>> - movl %cr4, %eax >>> - btsl $(X86_CR4_PAE_BIT), %eax >>> - movl %eax, %cr4 >>> - >>> - movl $MSR_EFER, %ecx >>> - rdmsr >>> - btsl $_EFER_LME, %eax >>> - wrmsr >>> - >>> - /* Disable interrupts - the firmware's IDT does not work in long mode */ >>> - cli >>> - >>> - /* Enable paging */ >>> - movl %cr0, %eax >>> - btsl $X86_CR0_PG_BIT, %eax >>> - movl %eax, %cr0 >>> - ret >>> -SYM_FUNC_END(efi32_enable_long_mode) >>> - >>> -/* >>> - * This is the common EFI stub entry point for mixed mode. It sets up the GDT >>> - * and page tables needed for 64-bit execution, after which it calls the >>> - * common 64-bit EFI entrypoint efi_stub_entry(). >>> - * >>> - * Arguments: 0(%esp) image handle >>> - * 4(%esp) EFI system table pointer >>> - * %ebx struct boot_params pointer (or NULL) >>> - * >>> - * Since this is the point of no return for ordinary execution, no registers >>> - * are considered live except for the function parameters. [Note that the EFI >>> - * stub may still exit and return to the firmware using the Exit() EFI boot >>> - * service.] >>> - */ >>> -SYM_FUNC_START_LOCAL(efi32_startup) >>> - movl %esp, %ebp >>> - >>> - subl $8, %esp >>> - sgdtl (%esp) /* Save GDT descriptor to the stack */ >>> - movl 2(%esp), %esi /* Existing GDT pointer */ >>> - movzwl (%esp), %ecx /* Existing GDT limit */ >>> - inc %ecx /* Existing GDT size */ >>> - andl $~7, %ecx /* Ensure size is multiple of 8 */ >>> - >>> - subl %ecx, %esp /* Allocate new GDT */ >>> - andl $~15, %esp /* Realign the stack */ >>> - movl %esp, %edi /* New GDT address */ >>> - leal 7(%ecx), %eax /* New GDT limit */ >>> - pushw %cx /* Push 64-bit CS (for LJMP below) */ >>> - pushl %edi /* Push new GDT address */ >>> - pushw %ax /* Push new GDT limit */ >>> - >>> - /* Copy GDT to the stack and add a 64-bit code segment at the end */ >>> - movl $GDT_ENTRY(DESC_CODE64, 0, 0xfffff) & 0xffffffff, (%edi,%ecx) >>> - movl $GDT_ENTRY(DESC_CODE64, 0, 0xfffff) >> 32, 4(%edi,%ecx) >>> - shrl $2, %ecx >>> - cld >>> - rep movsl /* Copy the firmware GDT */ >>> - lgdtl (%esp) /* Switch to the new GDT */ >>> - >>> - call 1f >>> -1: pop %edi >>> - >>> - /* Record mixed mode entry */ >>> - movb $0x0, (efi_is64 - 1b)(%edi) >>> - >>> - /* Set up indirect far call to re-enter 32-bit mode */ >>> - leal (efi32_call - 1b)(%edi), %eax >>> - addl %eax, (%eax) >>> - movw %cs, 4(%eax) >>> - >>> - /* Disable paging */ >>> - movl %cr0, %eax >>> - btrl $X86_CR0_PG_BIT, %eax >>> - movl %eax, %cr0 >>> - >>> - /* Set up 1:1 mapping */ >>> - leal (pte - 1b)(%edi), %eax >>> - movl $_PAGE_PRESENT | _PAGE_RW | _PAGE_PSE, %ecx >>> - leal (_PAGE_PRESENT | _PAGE_RW)(%eax), %edx >>> -2: movl %ecx, (%eax) >>> - addl $8, %eax >>> - addl $PMD_SIZE, %ecx >>> - jnc 2b >>> - >>> - movl $PAGE_SIZE, %ecx >>> - .irpc l, 0123 >>> - movl %edx, \l * 8(%eax) >>> - addl %ecx, %edx >>> - .endr >>> - addl %ecx, %eax >>> - movl %edx, (%eax) >>> - movl %eax, %cr3 >>> - >>> - call efi32_enable_long_mode >>> - >>> - /* Set up far jump to 64-bit mode (CS is already on the stack) */ >>> - leal (efi_stub_entry - 1b)(%edi), %eax >>> - movl %eax, 2(%esp) >>> - >>> - movl 0(%ebp), %edi >>> - movl 4(%ebp), %esi >>> - movl %ebx, %edx >>> - ljmpl *2(%esp) >>> -SYM_FUNC_END(efi32_startup) >>> - >>> -/* >>> - * efi_status_t efi32_pe_entry(efi_handle_t image_handle, >>> - * efi_system_table_32_t *sys_table) >>> - */ >>> -SYM_FUNC_START(efi32_pe_entry) >>> - pushl %ebx // save callee-save registers >>> - >>> - /* Check whether the CPU supports long mode */ >>> - movl $0x80000001, %eax // assume extended info support >>> - cpuid >>> - btl $29, %edx // check long mode bit >>> - jnc 1f >>> - leal 8(%esp), %esp // preserve stack alignment >>> - xor %ebx, %ebx // no struct boot_params pointer >>> - jmp efi32_startup // only ESP and EBX remain live >>> -1: movl $0x80000003, %eax // EFI_UNSUPPORTED >>> - popl %ebx >>> - RET >>> -SYM_FUNC_END(efi32_pe_entry) >>> - >>> -#ifdef CONFIG_EFI_HANDOVER_PROTOCOL >>> - .org efi32_stub_entry + 0x200 >>> - .code64 >>> -SYM_FUNC_START_NOALIGN(efi64_stub_entry) >>> - jmp efi_handover_entry >>> -SYM_FUNC_END(efi64_stub_entry) >>> -#endif >>> - >>> - .data >>> - .balign 8 >>> -SYM_DATA_START_LOCAL(efi32_call) >>> - .long efi_enter32 - . >>> - .word 0x0 >>> -SYM_DATA_END(efi32_call) >>> -SYM_DATA(efi_is64, .byte 1) >>> - >>> - .bss >>> - .balign PAGE_SIZE >>> -SYM_DATA_LOCAL(pte, .fill 6 * PAGE_SIZE, 1, 0)
Powered by blists - more mailing lists