higher half in x86_64

kernel is now located at -2GB
heap blocks are aligned on block size
paging will allocate new page tables on heap

1 files changed, 46 insertions, 112 deletions

diff --git a/kernel/src/boot/boot.S b/kernel/src/boot/boot.S
index a96be00..704acbf 100644
--- a/kernel/src/boot/boot.S
+++ b/kernel/src/boot/boot.S
@@ -1,99 +1,60 @@
 .code32
 .extern begin_long_mode
 
-.set KERNEL_VMA, 0xc0000000
+.section .boot32.text, "a"
 
-.section .boot.text, "a"
 .global _start
 _start:
 	cli
-	mov $stack_top - KERNEL_VMA, %esp
+	mov $stack_top, %esp
 	pushl $0
 	pushl %eax
 	pushl $0
 	pushl %ebx
 
-	call check_multiboot
-	call check_cpuid
-	call check_long_mode
-
 	call setup_page_tables
 	call enable_paging
 
-	addl $KERNEL_VMA, %esp
-	mov $4f, %ecx
-	jmp *%ecx
-
-check_multiboot:
-	cmp $0x36d76289, %eax
-	jne no_multiboot
-
-	ret
-
-check_cpuid:
-	pushfl
-	pop %eax
-	mov %eax, %ecx
-	xor $1<<21, %eax
-	push %eax
-	popfl
-	pushfl
-	pop %eax
-	push %ecx
-	popfl
-	cmp %eax, %ecx
-	je no_cpuid
-
-	ret
-
-check_long_mode:
-	mov $0x80000000, %eax
-	cpuid
-	cmp $0x80000001, %eax
-	jb no_long_mode
-
-	mov $0x80000001, %eax
-	cpuid
-	test $1<<29, %edx
-	jz no_long_mode
-
-	ret
+	lgdt gdtp
+	ljmp $0x08, $begin_long_mode
 
 setup_page_tables:
-	mov $pt_lvl3 - KERNEL_VMA, %eax
-	or $0x3, %eax
-	mov %eax, pt_lvl4 - KERNEL_VMA
-
-	// 0x00000000 - 0x00200000 : 0x00000000 - 0x00200000
-	mov $pt_lvl2 - KERNEL_VMA, %eax
+// first 2mb
+	mov $pt_lvl3, %eax
 	or $0x3, %eax
-	mov %eax, pt_lvl3 - KERNEL_VMA
+	mov %eax, pt_lvl4
 
-	// 0xc0000000 - 0xc0200000 : 0xc0000000 - 0xc0200000
-	mov $pt_lvl2_hh - KERNEL_VMA, %eax
+	mov $pt_lvl2, %eax
 	or $0x3, %eax
-	mov %eax, pt_lvl3 + 24 - KERNEL_VMA
+	mov %eax, pt_lvl3
 
-// first 2mb
 	xor %ecx, %ecx
 1:
 	movl $0x00200000, %eax
 	mul %ecx
 	or $0b10000011, %eax
-	movl $pt_lvl2 - KERNEL_VMA, %edx
+	movl $pt_lvl2, %edx
 	leal (%edx, %ecx, 8), %edx
 	movl %eax, (%edx)
 	inc %ecx
 	cmp $1, %ecx
 	jne 1b
 
-// first 2mb in higher_half
+// first 2mb in hh
+	mov $pt_lvl3_hh, %eax
+	or $0x3, %eax
+	mov %eax, pt_lvl4 + 4096 - 8
+
+	mov $pt_lvl2_hh, %eax
+	or $0x3, %eax
+	mov %eax, pt_lvl3_hh + 4096 - 16
+
 	xor %ecx, %ecx
 2:
 	movl $0x00200000, %eax
 	mul %ecx
 	or $0b10000011, %eax
-	movl $pt_lvl2_hh - KERNEL_VMA, %edx
+	movl $pt_lvl2_hh, %edx
 	leal (%edx, %ecx, 8), %edx
 	movl %eax, (%edx)
 	inc %ecx
@@ -115,7 +76,7 @@ enable_paging:
 	wrmsr
 
 	// pt_lvl4
-	mov $pt_lvl4 - KERNEL_VMA, %eax
+	mov $pt_lvl4, %eax
 	mov %eax, %cr3
 
 	// enable paging (+ protected mode if not already enabled)
@@ -125,70 +86,43 @@ enable_paging:
 
 	ret
 
-no_multiboot:
-	hlt
 
-no_cpuid:
-	hlt
+.section .boot32.rodata
 
-no_long_mode:
-	hlt
-
-.section .text
-4:
-	lgdt gdtp
-	ljmp $0x08, $begin_long_mode
+gdt:
+gdt_null = . - gdt
+	.quad 0
+gdt_code = . - gdt
+	.long 0xFFFF
+	.byte 0
+	.byte 0x9A
+	.byte 0xAF
+	.byte 0
+gdt_data = . - gdt
+	.long 0xFFFF
+	.byte 0
+	.byte 0xA2
+	.byte 0xAF
+	.byte 0
+gdtp:
+	.word . - gdt - 1
+	.quad gdt
 
 
-.section .bss
+.section .boot32.bss
 .align 4096
 
-// stack
-stack_bottom:
-	.skip 4096*16
-stack_top:
-
-
-// page tables
 pt_lvl4:
 	.skip 4096
 pt_lvl3:
 	.skip 4096
+pt_lvl3_hh:
+	.skip 4096
 pt_lvl2:
 	.skip 4096
 pt_lvl2_hh:
 	.skip 4096
 
-
-// Access bits
-.section .rodata
-.set PRESENT,		1 << 7
-.set NOT_SYS,		1 << 4
-.set EXEC,		1 << 3
-.set DC,		1 << 2
-.set RW,		1 << 1
-.set ACCESSED,		1 << 0
-
-// Flags bits
-.set GRAN_4K,		1 << 7
-.set SZ_32,		1 << 6
-.set LONG_MODE,		1 << 5
-
-gdt:
-gdt_null = . - gdt
-	.quad 0
-gdt_code = . - gdt
-	.long 0xFFFF				// Limit & Base (low, bits 0-15)
-	.byte 0					// Base (mid, bits 16-23)
-	.byte PRESENT | NOT_SYS | EXEC | RW	// Access
-	.byte GRAN_4K | LONG_MODE | 0xF		// Flags & Limit (high, bits 16-19)
-	.byte 0					// Base (high, bits 24-31)
-gdt_data = . - gdt
-	.long 0xFFFF
-	.byte 0
-	.byte PRESENT | NOT_SYS | RW
-	.byte GRAN_4K | SZ_32 | 0xF
-	.byte 0
-gdtp:
-	.word . - gdt - 1
-	.quad gdt
+stack_bottom:
+	.skip 4096*4
+stack_top: