vmlinux-objs-$(CONFIG_EFI_STUB) += $(obj)/eboot.o $(obj)/efi_stub_$(BITS).o \
$(objtree)/drivers/firmware/efi/libstub/lib.a
+vmlinux-objs-$(CONFIG_EFI_MIXED) += $(obj)/efi_thunk_$(BITS).o
$(obj)/vmlinux: $(vmlinux-objs-y) FORCE
$(call if_changed,ld)
#include <asm/processor-flags.h>
#include "../../platform/efi/efi_stub_64.S"
-
-#ifdef CONFIG_EFI_MIXED
- .code64
- .text
-ENTRY(efi64_thunk)
- push %rbp
- push %rbx
-
- subq $16, %rsp
- leaq efi_exit32(%rip), %rax
- movl %eax, 8(%rsp)
- leaq efi_gdt64(%rip), %rax
- movl %eax, 4(%rsp)
- movl %eax, 2(%rax) /* Fixup the gdt base address */
- leaq efi32_boot_gdt(%rip), %rax
- movl %eax, (%rsp)
-
- call __efi64_thunk
-
- addq $16, %rsp
- pop %rbx
- pop %rbp
- ret
-ENDPROC(efi64_thunk)
-#endif /* CONFIG_EFI_MIXED */
--- /dev/null
+/*
+ * 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 before we make EFI serivce calls,
+ * since the firmware's 32-bit IDT is still currently installed and it
+ * needs to be able to service interrupts.
+ *
+ * On the plus side, we don't have to worry about mangling 64-bit
+ * addresses into 32-bits because we're executing with an identify
+ * mapped pagetable and haven't transitioned to 64-bit virtual addresses
+ * yet.
+ */
+
+#include <linux/linkage.h>
+#include <asm/msr.h>
+#include <asm/page_types.h>
+#include <asm/processor-flags.h>
+#include <asm/segment.h>
+
+ .code64
+ .text
+ENTRY(efi64_thunk)
+ push %rbp
+ push %rbx
+
+ subq $8, %rsp
+ leaq efi_exit32(%rip), %rax
+ movl %eax, 4(%rsp)
+ leaq efi_gdt64(%rip), %rax
+ movl %eax, (%rsp)
+ movl %eax, 2(%rax) /* Fixup the gdt base address */
+
+ movl %ds, %eax
+ push %rax
+ movl %es, %eax
+ push %rax
+ movl %ss, %eax
+ push %rax
+
+ /*
+ * Convert x86-64 ABI params to i386 ABI
+ */
+ 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)
+
+ sgdt save_gdt(%rip)
+
+ leaq 1f(%rip), %rbx
+ movq %rbx, func_rt_ptr(%rip)
+
+ /*
+ * Switch to gdt with 32-bit segments. This is the firmware GDT
+ * that was installed when the kernel started executing. This
+ * pointer was saved at the EFI stub entry point in head_64.S.
+ */
+ leaq efi32_boot_gdt(%rip), %rax
+ lgdt (%rax)
+
+ pushq $__KERNEL_CS
+ leaq efi_enter32(%rip), %rax
+ pushq %rax
+ lretq
+
+1: addq $32, %rsp
+
+ lgdt save_gdt(%rip)
+
+ 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:
+ addq $8, %rsp
+ pop %rbx
+ pop %rbp
+ ret
+ENDPROC(efi64_thunk)
+
+ENTRY(efi_exit32)
+ movq func_rt_ptr(%rip), %rax
+ push %rax
+ mov %rdi, %rax
+ ret
+ENDPROC(efi_exit32)
+
+ .code32
+/*
+ * EFI service pointer must be in %edi.
+ *
+ * The stack should represent the 32-bit calling convention.
+ */
+ENTRY(efi_enter32)
+ movl $__KERNEL_DS, %eax
+ movl %eax, %ds
+ movl %eax, %es
+ movl %eax, %ss
+
+ /* Reload pgtables */
+ movl %cr3, %eax
+ movl %eax, %cr3
+
+ /* 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
+
+ /*
+ * Some firmware will return with interrupts enabled. Be sure to
+ * disable them before we switch GDTs.
+ */
+ cli
+
+ movl 56(%esp), %eax
+ movl %eax, 2(%eax)
+ lgdtl (%eax)
+
+ movl %cr4, %eax
+ btsl $(X86_CR4_PAE_BIT), %eax
+ movl %eax, %cr4
+
+ movl %cr3, %eax
+ movl %eax, %cr3
+
+ movl $MSR_EFER, %ecx
+ rdmsr
+ btsl $_EFER_LME, %eax
+ wrmsr
+
+ xorl %eax, %eax
+ lldt %ax
+
+ movl 60(%esp), %eax
+ pushl $__KERNEL_CS
+ pushl %eax
+
+ /* Enable paging */
+ movl %cr0, %eax
+ btsl $X86_CR0_PG_BIT, %eax
+ movl %eax, %cr0
+ lret
+ENDPROC(efi_enter32)
+
+ .data
+ .balign 8
+ .global efi32_boot_gdt
+efi32_boot_gdt: .word 0
+ .quad 0
+
+save_gdt: .word 0
+ .quad 0
+func_rt_ptr: .quad 0
+
+ .global efi_gdt64
+efi_gdt64:
+ .word efi_gdt64_end - efi_gdt64
+ .long 0 /* Filled out by user */
+ .word 0
+ .quad 0x0000000000000000 /* NULL descriptor */
+ .quad 0x00af9a000000ffff /* __KERNEL_CS */
+ .quad 0x00cf92000000ffff /* __KERNEL_DS */
+ .quad 0x0080890000000000 /* TS descriptor */
+ .quad 0x0000000000000000 /* TS continued */
+efi_gdt64_end:
ret
ENDPROC(efi_call)
-#ifdef CONFIG_EFI_MIXED
-
-/*
- * We run this function from the 1:1 mapping.
- *
- * This function must be invoked with a 1:1 mapped stack.
- */
-ENTRY(__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)
-
- sgdt save_gdt(%rip)
-
- leaq 1f(%rip), %rbx
- movq %rbx, func_rt_ptr(%rip)
-
- /* Switch to gdt with 32-bit segments */
- movl 64(%rsp), %eax
- lgdt (%rax)
-
- leaq efi_enter32(%rip), %rax
- pushq $__KERNEL_CS
- pushq %rax
- lretq
-
-1: addq $32, %rsp
-
- lgdt save_gdt(%rip)
-
- 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
-ENDPROC(__efi64_thunk)
-
-ENTRY(efi_exit32)
- movq func_rt_ptr(%rip), %rax
- push %rax
- mov %rdi, %rax
- ret
-ENDPROC(efi_exit32)
-
- .code32
-/*
- * EFI service pointer must be in %edi.
- *
- * The stack should represent the 32-bit calling convention.
- */
-ENTRY(efi_enter32)
- movl $__KERNEL_DS, %eax
- movl %eax, %ds
- movl %eax, %es
- movl %eax, %ss
-
- /* Reload pgtables */
- movl %cr3, %eax
- movl %eax, %cr3
-
- /* 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
-
- /*
- * Some firmware will return with interrupts enabled. Be sure to
- * disable them before we switch GDTs.
- */
- cli
-
- movl 68(%esp), %eax
- movl %eax, 2(%eax)
- lgdtl (%eax)
-
- movl %cr4, %eax
- btsl $(X86_CR4_PAE_BIT), %eax
- movl %eax, %cr4
-
- movl %cr3, %eax
- movl %eax, %cr3
-
- movl $MSR_EFER, %ecx
- rdmsr
- btsl $_EFER_LME, %eax
- wrmsr
-
- xorl %eax, %eax
- lldt %ax
-
- movl 72(%esp), %eax
- pushl $__KERNEL_CS
- pushl %eax
-
- /* Enable paging */
- movl %cr0, %eax
- btsl $X86_CR0_PG_BIT, %eax
- movl %eax, %cr0
- lret
-ENDPROC(efi_enter32)
-
- .data
- .balign 8
- .global efi32_boot_gdt
-efi32_boot_gdt: .word 0
- .quad 0
-
-save_gdt: .word 0
- .quad 0
-func_rt_ptr: .quad 0
-
- .global efi_gdt64
-efi_gdt64:
- .word efi_gdt64_end - efi_gdt64
- .long 0 /* Filled out by user */
- .word 0
- .quad 0x0000000000000000 /* NULL descriptor */
- .quad 0x00af9a000000ffff /* __KERNEL_CS */
- .quad 0x00cf92000000ffff /* __KERNEL_DS */
- .quad 0x0080890000000000 /* TS descriptor */
- .quad 0x0000000000000000 /* TS continued */
-efi_gdt64_end:
-#endif /* CONFIG_EFI_MIXED */
-
.data
ENTRY(efi_scratch)
.fill 3,8,0
/*
* Copyright (C) 2014 Intel Corporation; author Matt Fleming
+ *
+ * Support for invoking 32-bit EFI runtime services from a 64-bit
+ * kernel.
+ *
+ * The below thunking functions are only used after ExitBootServices()
+ * has been called. This simplifies things considerably as compared with
+ * the early EFI thunking because we can leave all the kernel state
+ * intact (GDT, IDT, etc) and simply invoke the the 32-bit EFI runtime
+ * services from __KERNEL32_CS. This means we can continue to service
+ * interrupts across an EFI mixed mode call.
+ *
+ * We do however, need to handle the fact that we're running in a full
+ * 64-bit virtual address space. Things like the stack and instruction
+ * addresses need to be accessible by the 32-bit firmware, so we rely on
+ * using the identity mappings in the EFI page table to access the stack
+ * and kernel text (see efi_setup_page_tables()).
*/
#include <linux/linkage.h>
#include <asm/page_types.h>
+#include <asm/segment.h>
.text
.code64
leaq efi_exit32(%rip), %rbx
subq %rax, %rbx
movl %ebx, 8(%rsp)
- leaq efi_gdt64(%rip), %rbx
- subq %rax, %rbx
- movl %ebx, 2(%ebx)
- movl %ebx, 4(%rsp)
- leaq efi_gdt32(%rip), %rbx
- subq %rax, %rbx
- movl %ebx, 2(%ebx)
- movl %ebx, (%rsp)
leaq __efi64_thunk(%rip), %rbx
subq %rax, %rbx
retq
ENDPROC(efi64_thunk)
- .data
-efi_gdt32:
- .word efi_gdt32_end - efi_gdt32
- .long 0 /* Filled out above */
- .word 0
- .quad 0x0000000000000000 /* NULL descriptor */
- .quad 0x00cf9a000000ffff /* __KERNEL_CS */
- .quad 0x00cf93000000ffff /* __KERNEL_DS */
-efi_gdt32_end:
+/*
+ * We run this function from the 1:1 mapping.
+ *
+ * This function must be invoked with a 1:1 mapped stack.
+ */
+ENTRY(__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)
+
+ /* Switch to 32-bit descriptor */
+ pushq $__KERNEL32_CS
+ leaq efi_enter32(%rip), %rax
+ pushq %rax
+ lretq
+
+1: addq $32, %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
+ENDPROC(__efi64_thunk)
+
+ENTRY(efi_exit32)
+ movq func_rt_ptr(%rip), %rax
+ push %rax
+ mov %rdi, %rax
+ ret
+ENDPROC(efi_exit32)
+
+ .code32
+/*
+ * EFI service pointer must be in %edi.
+ *
+ * The stack should represent the 32-bit calling convention.
+ */
+ENTRY(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
+
+ lret
+ENDPROC(efi_enter32)
+
+ .data
+ .balign 8
+func_rt_ptr: .quad 0
efi_saved_sp: .quad 0
projects / GitHub / MotorolaMobilityLLC / kernel-slsi.git / commitdiff