.text
#include <linux/linkage.h>
#include <asm/segment.h>
+#include <asm/pgtable.h>
#include <asm/page.h>
#include <asm/msr.h>
cld
# setup data segment
movw %cs, %ax
- movw %ax, %ds # Make ds:0 point to wakeup_start
+ movw %ax, %ds # Make ds:0 point to wakeup_start
movw %ax, %ss
- mov $(wakeup_stack - wakeup_code), %sp # Private stack is needed for ASUS board
+ # Private stack is needed for ASUS board
+ mov $(wakeup_stack - wakeup_code), %sp
- pushl $0 # Kill any dangerous flags
+ pushl $0 # Kill any dangerous flags
popfl
movl real_magic - wakeup_code, %eax
cmpl $0x12345678, %eax
jne bogus_real_magic
+ call verify_cpu # Verify the cpu supports long
+ # mode
+ testl %eax, %eax
+ jnz no_longmode
+
testl $1, video_flags - wakeup_code
jz 1f
lcall $0xc000,$3
movw %cs, %ax
- movw %ax, %ds # Bios might have played with that
+ movw %ax, %ds # Bios might have played with that
movw %ax, %ss
1:
movb $0xa2, %al ; outb %al, $0x80
- lidt %ds:idt_48a - wakeup_code
- xorl %eax, %eax
- movw %ds, %ax # (Convert %ds:gdt to a linear ptr)
- shll $4, %eax
- addl $(gdta - wakeup_code), %eax
- movl %eax, gdt_48a +2 - wakeup_code
+ mov %ds, %ax # Find 32bit wakeup_code addr
+ movzx %ax, %esi # (Convert %ds:gdt to a liner ptr)
+ shll $4, %esi
+ # Fix up the vectors
+ addl %esi, wakeup_32_vector - wakeup_code
+ addl %esi, wakeup_long64_vector - wakeup_code
+ addl %esi, gdt_48a + 2 - wakeup_code # Fixup the gdt pointer
+
+ lidtl %ds:idt_48a - wakeup_code
lgdtl %ds:gdt_48a - wakeup_code # load gdt with whatever is
# appropriate
jmp 1f
1:
- .byte 0x66, 0xea # prefix + jmpi-opcode
- .long wakeup_32 - __START_KERNEL_map
- .word __KERNEL_CS
+ ljmpl *(wakeup_32_vector - wakeup_code)
+
+ .balign 4
+wakeup_32_vector:
+ .long wakeup_32 - wakeup_code
+ .word __KERNEL32_CS, 0
.code32
wakeup_32:
# Running in this code, but at low address; paging is not yet turned on.
movb $0xa5, %al ; outb %al, $0x80
- /* Check if extended functions are implemented */
- movl $0x80000000, %eax
- cpuid
- cmpl $0x80000000, %eax
- jbe bogus_cpu
- wbinvd
- mov $0x80000001, %eax
- cpuid
- btl $29, %edx
- jnc bogus_cpu
- movl %edx,%edi
-
- movw $__KERNEL_DS, %ax
- movw %ax, %ds
- movw %ax, %es
- movw %ax, %fs
- movw %ax, %gs
-
- movw $__KERNEL_DS, %ax
- movw %ax, %ss
+ movl $__KERNEL_DS, %eax
+ movl %eax, %ds
- mov $(wakeup_stack - __START_KERNEL_map), %esp
- movl saved_magic - __START_KERNEL_map, %eax
- cmpl $0x9abcdef0, %eax
- jne bogus_32_magic
+ movw $0x0e00 + 'i', %ds:(0xb8012)
+ movb $0xa8, %al ; outb %al, $0x80;
/*
* Prepare for entering 64bits mode
*/
- /* Enable PAE mode and PGE */
+ /* Enable PAE */
xorl %eax, %eax
btsl $5, %eax
- btsl $7, %eax
movl %eax, %cr4
/* Setup early boot stage 4 level pagetables */
- movl $(wakeup_level4_pgt - __START_KERNEL_map), %eax
+ leal (wakeup_level4_pgt - wakeup_code)(%esi), %eax
movl %eax, %cr3
- /* Setup EFER (Extended Feature Enable Register) */
- movl $MSR_EFER, %ecx
- rdmsr
- /* Fool rdmsr and reset %eax to avoid dependences */
- xorl %eax, %eax
+ /* Check if nx is implemented */
+ movl $0x80000001, %eax
+ cpuid
+ movl %edx,%edi
+
/* Enable Long Mode */
+ xorl %eax, %eax
btsl $_EFER_LME, %eax
- /* Enable System Call */
- btsl $_EFER_SCE, %eax
- /* No Execute supported? */
+ /* No Execute supported? */
btl $20,%edi
jnc 1f
btsl $_EFER_NX, %eax
-1:
/* Make changes effective */
+1: movl $MSR_EFER, %ecx
+ xorl %edx, %edx
wrmsr
- wbinvd
xorl %eax, %eax
btsl $31, %eax /* Enable paging and in turn activate Long Mode */
btsl $0, %eax /* Enable protected mode */
- btsl $1, %eax /* Enable MP */
- btsl $4, %eax /* Enable ET */
- btsl $5, %eax /* Enable NE */
- btsl $16, %eax /* Enable WP */
- btsl $18, %eax /* Enable AM */
/* Make changes effective */
movl %eax, %cr0
+
/* At this point:
CR4.PAE must be 1
CS.L must be 0
Next instruction must be a branch
This must be on identity-mapped page
*/
- jmp reach_compatibility_mode
-reach_compatibility_mode:
- movw $0x0e00 + 'i', %ds:(0xb8012)
- movb $0xa8, %al ; outb %al, $0x80;
-
/*
* At this point we're in long mode but in 32bit compatibility mode
* with EFER.LME = 1, CS.L = 0, CS.D = 1 (and in turn
* the new gdt/idt that has __KERNEL_CS with CS.L = 1.
*/
- movw $0x0e00 + 'n', %ds:(0xb8014)
- movb $0xa9, %al ; outb %al, $0x80
-
- /* Load new GDT with the 64bit segment using 32bit descriptor */
- movl $(pGDT32 - __START_KERNEL_map), %eax
- lgdt (%eax)
-
- movl $(wakeup_jumpvector - __START_KERNEL_map), %eax
/* Finally jump in 64bit mode */
- ljmp *(%eax)
+ ljmp *(wakeup_long64_vector - wakeup_code)(%esi)
-wakeup_jumpvector:
- .long wakeup_long64 - __START_KERNEL_map
- .word __KERNEL_CS
+ .balign 4
+wakeup_long64_vector:
+ .long wakeup_long64 - wakeup_code
+ .word __KERNEL_CS, 0
.code64
- /* Hooray, we are in Long 64-bit mode (but still running in low memory) */
+ /* Hooray, we are in Long 64-bit mode (but still running in
+ * low memory)
+ */
wakeup_long64:
/*
* We must switch to a new descriptor in kernel space for the GDT
* addresses where we're currently running on. We have to do that here
* because in 32bit we couldn't load a 64bit linear address.
*/
- lgdt cpu_gdt_descr - __START_KERNEL_map
+ lgdt cpu_gdt_descr
+
+ movw $0x0e00 + 'n', %ds:(0xb8014)
+ movb $0xa9, %al ; outb %al, $0x80
+
+ movq saved_magic, %rax
+ movq $0x123456789abcdef0, %rdx
+ cmpq %rdx, %rax
+ jne bogus_64_magic
movw $0x0e00 + 'u', %ds:(0xb8016)
.align 64
gdta:
+ /* Its good to keep gdt in sync with one in trampoline.S */
.word 0, 0, 0, 0 # dummy
-
- .word 0, 0, 0, 0 # unused
-
- .word 0xFFFF # 4Gb - (0x100000*0x1000 = 4Gb)
- .word 0 # base address = 0
- .word 0x9B00 # code read/exec. ??? Why I need 0x9B00 (as opposed to 0x9A00 in order for this to work?)
- .word 0x00CF # granularity = 4096, 386
- # (+5th nibble of limit)
-
- .word 0xFFFF # 4Gb - (0x100000*0x1000 = 4Gb)
- .word 0 # base address = 0
- .word 0x9200 # data read/write
- .word 0x00CF # granularity = 4096, 386
- # (+5th nibble of limit)
-# this is 64bit descriptor for code
- .word 0xFFFF
- .word 0
- .word 0x9A00 # code read/exec
- .word 0x00AF # as above, but it is long mode and with D=0
+ /* ??? Why I need the accessed bit set in order for this to work? */
+ .quad 0x00cf9b000000ffff # __KERNEL32_CS
+ .quad 0x00af9b000000ffff # __KERNEL_CS
+ .quad 0x00cf93000000ffff # __KERNEL_DS
idt_48a:
.word 0 # idt limit = 0
.word 0, 0 # idt base = 0L
gdt_48a:
- .word 0x8000 # gdt limit=2048,
+ .word 0x800 # gdt limit=2048,
# 256 GDT entries
- .word 0, 0 # gdt base (filled in later)
-
+ .long gdta - wakeup_code # gdt base (relocated in later)
real_magic: .quad 0
video_mode: .quad 0
video_flags: .quad 0
+.code16
bogus_real_magic:
- movb $0xba,%al ; outb %al,$0x80
+ movb $0xba,%al ; outb %al,$0x80
jmp bogus_real_magic
-bogus_32_magic:
+.code64
+bogus_64_magic:
movb $0xb3,%al ; outb %al,$0x80
- jmp bogus_32_magic
+ jmp bogus_64_magic
-bogus_cpu:
- movb $0xbc,%al ; outb %al,$0x80
- jmp bogus_cpu
+.code16
+no_longmode:
+ movb $0xbc,%al ; outb %al,$0x80
+ jmp no_longmode
+#include "../verify_cpu.S"
/* This code uses an extended set of video mode numbers. These include:
* Aliases for standard modes
#define VIDEO_FIRST_V7 0x0900
# Setting of user mode (AX=mode ID) => CF=success
+.code16
mode_seta:
movw %ax, %bx
#if 0
.org 0xff0
wakeup_stack: # Just below end of page
+.org 0x1000
+ENTRY(wakeup_level4_pgt)
+ .quad level3_ident_pgt - __START_KERNEL_map + _KERNPG_TABLE
+ .fill 510,8,0
+ /* (2^48-(2*1024*1024*1024))/(2^39) = 511 */
+ .quad level3_kernel_pgt - __START_KERNEL_map + _KERNPG_TABLE
+
ENTRY(wakeup_end)
##
movq $0x123456789abcdef0, %rdx
movq %rdx, saved_magic
- movl saved_magic - __START_KERNEL_map, %eax
- cmpl $0x9abcdef0, %eax
- jne bogus_32_magic
+ movq saved_magic, %rax
+ movq $0x123456789abcdef0, %rdx
+ cmpq %rdx, %rax
+ jne bogus_64_magic
# restore the regs we used
popq %rdx