diff options
Diffstat (limited to 'arch/x86/platform/efi/efi_thunk_64.S')
| -rw-r--r-- | arch/x86/platform/efi/efi_thunk_64.S | 121 |
1 files changed, 20 insertions, 101 deletions
diff --git a/arch/x86/platform/efi/efi_thunk_64.S b/arch/x86/platform/efi/efi_thunk_64.S index 3189f1394701..26f0da238c1c 100644 --- a/arch/x86/platform/efi/efi_thunk_64.S +++ b/arch/x86/platform/efi/efi_thunk_64.S @@ -25,15 +25,16 @@ .text .code64 -SYM_FUNC_START(efi64_thunk) +SYM_CODE_START(__efi64_thunk) push %rbp push %rbx /* * Switch to 1:1 mapped 32-bit stack pointer. */ - movq %rsp, efi_saved_sp(%rip) + movq %rsp, %rax movq efi_scratch(%rip), %rsp + push %rax /* * Calculate the physical address of the kernel text. @@ -41,113 +42,31 @@ SYM_FUNC_START(efi64_thunk) movq $__START_KERNEL_map, %rax subq phys_base(%rip), %rax - /* - * Push some physical addresses onto the stack. This is easier - * to do now in a code64 section while the assembler can address - * 64-bit values. Note that all the addresses on the stack are - * 32-bit. - */ - subq $16, %rsp - leaq efi_exit32(%rip), %rbx - subq %rax, %rbx - movl %ebx, 8(%rsp) - - leaq __efi64_thunk(%rip), %rbx + leaq 1f(%rip), %rbp + leaq 2f(%rip), %rbx + subq %rax, %rbp subq %rax, %rbx - call *%rbx - - movq efi_saved_sp(%rip), %rsp - pop %rbx - pop %rbp - retq -SYM_FUNC_END(efi64_thunk) -/* - * We run this function from the 1:1 mapping. - * - * This function must be invoked with a 1:1 mapped stack. - */ -SYM_FUNC_START_LOCAL(__efi64_thunk) - movl %ds, %eax - push %rax - movl %es, %eax - push %rax - movl %ss, %eax - push %rax - - subq $32, %rsp - movl %esi, 0x0(%rsp) - movl %edx, 0x4(%rsp) - movl %ecx, 0x8(%rsp) - movq %r8, %rsi - movl %esi, 0xc(%rsp) - movq %r9, %rsi - movl %esi, 0x10(%rsp) - - leaq 1f(%rip), %rbx - movq %rbx, func_rt_ptr(%rip) + subq $28, %rsp + movl %ebx, 0x0(%rsp) /* return address */ + movl %esi, 0x4(%rsp) + movl %edx, 0x8(%rsp) + movl %ecx, 0xc(%rsp) + movl %r8d, 0x10(%rsp) + movl %r9d, 0x14(%rsp) /* Switch to 32-bit descriptor */ pushq $__KERNEL32_CS - leaq efi_enter32(%rip), %rax - pushq %rax + pushq %rdi /* EFI runtime service address */ lretq -1: addq $32, %rsp - +1: movq 24(%rsp), %rsp pop %rbx - movl %ebx, %ss - pop %rbx - movl %ebx, %es - pop %rbx - movl %ebx, %ds - - /* - * Convert 32-bit status code into 64-bit. - */ - test %rax, %rax - jz 1f - movl %eax, %ecx - andl $0x0fffffff, %ecx - andl $0xf0000000, %eax - shl $32, %rax - or %rcx, %rax -1: - ret -SYM_FUNC_END(__efi64_thunk) - -SYM_FUNC_START_LOCAL(efi_exit32) - movq func_rt_ptr(%rip), %rax - push %rax - mov %rdi, %rax - ret -SYM_FUNC_END(efi_exit32) + pop %rbp + retq .code32 -/* - * EFI service pointer must be in %edi. - * - * The stack should represent the 32-bit calling convention. - */ -SYM_FUNC_START_LOCAL(efi_enter32) - movl $__KERNEL_DS, %eax - movl %eax, %ds - movl %eax, %es - movl %eax, %ss - - call *%edi - - /* We must preserve return value */ - movl %eax, %edi - - movl 72(%esp), %eax - pushl $__KERNEL_CS - pushl %eax - +2: pushl $__KERNEL_CS + pushl %ebp lret -SYM_FUNC_END(efi_enter32) - - .data - .balign 8 -func_rt_ptr: .quad 0 -efi_saved_sp: .quad 0 +SYM_CODE_END(__efi64_thunk) |