WebSVN – HelenOS – Diff – /SPARTAN/trunk/arch/ia32/src/boot/boot.S



kernel_image_start:
	cli
	xorw %ax, %ax
	movw %ax, %ds
	movw %ax, %ss							# initialize stack segment register
	movl $BOOTSTRAP_OFFSET - 0x400, %esp				# initialize stack pointer
	
	call memmap_arch_init
	
	lgdt real_bootstrap_gdtr_boot					# initialize Global Descriptor Table register
	
	movl %cr0, %eax
	orl $0x1, %eax
	movl %eax, %cr0							# switch to protected mode
	

boot_image_start:
	movw $KDATA, %ax
	movw %ax, %es
	movw %ax, %gs
	movw %ax, %fs
	movw %ax, %ds							# kernel data + stack
	movw %ax, %ss
	
	movb $0xd1, %al							# enable A20 using the keyboard controller
	outb %al, $0x64
	movb $0xdf, %al
	outb %al, $0x60
	
	movl $BOOTSTRAP_OFFSET, %esi
	movl $BOOTSTRAP_OFFSET + BOOT_OFFSET, %edi
	movl $_hardcoded_kernel_size, %ecx
	cld
	rep movsb
	
	call map_kernel							# map kernel and turn paging on
	
	call main_bsp							# never returns
 
	cli
	hlt
	
multiboot_image_start:
	movl $BOOTSTRAP_OFFSET - 0x400, %esp				# initialize stack pointer
	
	lgdt protected_bootstrap_gdtr - 0x80000000			# initialize Global Descriptor Table register
 
	movw $KDATA, %cx
	movw %cx, %es
	movw %cx, %gs
	movw %cx, %fs
	movw %cx, %ds							# kernel data + stack
	movw %cx, %ss
	
	jmpl $KTEXT, $multiboot_meeting_point + BOOT_OFFSET
	multiboot_meeting_point:
	
	pushl %ebx							# save parameters from GRUB
	pushl %eax
	
	movl $BOOTSTRAP_OFFSET + BOOT_OFFSET, %esi
	movl $BOOTSTRAP_OFFSET, %edi
	movl $_hardcoded_unmapped_size, %ecx
	cld
	rep movsb
	
	call map_kernel							# map kernel and turn paging on
	
	popl %eax
	popl %ebx
	cmpl $MULTIBOOT_LOADER_MAGIC, %eax				# compare GRUB signature
	je valid_boot
		
		xorl %ecx, %ecx							# no memory size or map available
		movl %ecx, e801memorysize
		movl %ecx, e820counter

		mmap_invalid:
		movl %edx, e820counter
		
	invalid_boot:
	
	call main_bsp - BOOT_OFFSET					# never returns
 
	cli
	hlt
 
.global map_kernel

	# Here we setup mapping for both the unmapped and mapped sections of the kernel.
	# For simplicity, we set only one 4M page for 0x00000000 and one for 0x80000000.
	#
	movl %cr4, %ecx
	orl $(1<<4), %ecx
	movl %ecx, %cr4							# turn PSE on
	
	movl $((1<<7)|(1<<0)), %eax
	movl %eax, page_directory					# mapping 0x00000000 => 0x00000000
 
	movl $(page_directory+2048), %edx
	movl %eax, (%edx)						# mapping 0x80000000 => 0x00000000
 
	leal page_directory, %eax
	movl %eax, %cr3
	
	# turn paging on

Rev 314	Rev 323
Line 51...	Line 51...
51	kernel_image_start:	51	kernel_image_start:
52	cli	52	cli
53	xorw %ax, %ax	53	xorw %ax, %ax
54	movw %ax, %ds	54	movw %ax, %ds
55	movw %ax, %ss # initialize stack segment register	55	movw %ax, %ss # initialize stack segment register
56	movl $BOOTSTRAP_OFFSET - 0x400, %esp # initialize stack pointer	56	movl $BOOTSTRAP_OFFSET - 0x400, %esp # initialize stack pointer
57		57
58	call memmap_arch_init	58	call memmap_arch_init
59		59
60	lgdt real_bootstrap_gdtr_boot # initialize Global Descriptor Table register	60	lgdt real_bootstrap_gdtr_boot # initialize Global Descriptor Table register
61		61
62	movl %cr0, %eax	62	movl %cr0, %eax
63	orl $0x1, %eax	63	orl $0x1, %eax
64	movl %eax, %cr0 # switch to protected mode	64	movl %eax, %cr0 # switch to protected mode
65		65
Line 80...	Line 80...
80	boot_image_start:	80	boot_image_start:
81	movw $KDATA, %ax	81	movw $KDATA, %ax
82	movw %ax, %es	82	movw %ax, %es
83	movw %ax, %gs	83	movw %ax, %gs
84	movw %ax, %fs	84	movw %ax, %fs
85	movw %ax, %ds # kernel data + stack	85	movw %ax, %ds # kernel data + stack
86	movw %ax, %ss	86	movw %ax, %ss
87		87
88	movb $0xd1, %al # enable A20 using the keyboard controller	88	movb $0xd1, %al # enable A20 using the keyboard controller
89	outb %al, $0x64	89	outb %al, $0x64
90	movb $0xdf, %al	90	movb $0xdf, %al
91	outb %al, $0x60	91	outb %al, $0x60
92		92
93	movl $BOOTSTRAP_OFFSET, %esi	93	movl $BOOTSTRAP_OFFSET, %esi
94	movl $BOOTSTRAP_OFFSET + BOOT_OFFSET, %edi	94	movl $BOOTSTRAP_OFFSET + BOOT_OFFSET, %edi
95	movl $_hardcoded_kernel_size, %ecx	95	movl $_hardcoded_kernel_size, %ecx
96	cld	96	cld
97	rep movsb	97	rep movsb
98		98
99	call map_kernel # map kernel and turn paging on	99	call map_kernel # map kernel and turn paging on
100		100
101	call main_bsp # never returns	101	call main_bsp # never returns
102		102
103	cli	103	cli
104	hlt	104	hlt
105		105
106	multiboot_image_start:	106	multiboot_image_start:
107	movl $BOOTSTRAP_OFFSET - 0x400, %esp # initialize stack pointer	107	movl $BOOTSTRAP_OFFSET - 0x400, %esp # initialize stack pointer
108		108
109	lgdt protected_bootstrap_gdtr - 0x80000000 # initialize Global Descriptor Table register	109	lgdt protected_bootstrap_gdtr - 0x80000000 # initialize Global Descriptor Table register
110		110
111	movw $KDATA, %cx	111	movw $KDATA, %cx
112	movw %cx, %es	112	movw %cx, %es
113	movw %cx, %gs	113	movw %cx, %gs
114	movw %cx, %fs	114	movw %cx, %fs
115	movw %cx, %ds # kernel data + stack	115	movw %cx, %ds # kernel data + stack
116	movw %cx, %ss	116	movw %cx, %ss
117		117
118	jmpl $KTEXT, $multiboot_meeting_point + BOOT_OFFSET	118	jmpl $KTEXT, $multiboot_meeting_point + BOOT_OFFSET
119	multiboot_meeting_point:	119	multiboot_meeting_point:
120		120
121	pushl %ebx # save parameters from GRUB	121	pushl %ebx # save parameters from GRUB
122	pushl %eax	122	pushl %eax
123		123
124	movl $BOOTSTRAP_OFFSET + BOOT_OFFSET, %esi	124	movl $BOOTSTRAP_OFFSET + BOOT_OFFSET, %esi
125	movl $BOOTSTRAP_OFFSET, %edi	125	movl $BOOTSTRAP_OFFSET, %edi
126	movl $_hardcoded_unmapped_size, %ecx	126	movl $_hardcoded_unmapped_size, %ecx
127	cld	127	cld
128	rep movsb	128	rep movsb
129		129
130	call map_kernel # map kernel and turn paging on	130	call map_kernel # map kernel and turn paging on
131		131
132	popl %eax	132	popl %eax
133	popl %ebx	133	popl %ebx
134	cmpl $MULTIBOOT_LOADER_MAGIC, %eax # compare GRUB signature	134	cmpl $MULTIBOOT_LOADER_MAGIC, %eax # compare GRUB signature
135	je valid_boot	135	je valid_boot
136		136
137	xorl %ecx, %ecx # no memory size or map available	137	xorl %ecx, %ecx # no memory size or map available
138	movl %ecx, e801memorysize	138	movl %ecx, e801memorysize
139	movl %ecx, e820counter	139	movl %ecx, e820counter
Line 201...	Line 201...
201	mmap_invalid:	201	mmap_invalid:
202	movl %edx, e820counter	202	movl %edx, e820counter
203		203
204	invalid_boot:	204	invalid_boot:
205		205
206	call main_bsp - BOOT_OFFSET # never returns	206	call main_bsp - BOOT_OFFSET # never returns
207		207
208	cli	208	cli
209	hlt	209	hlt
210		210
211	.global map_kernel	211	.global map_kernel
Line 214...	Line 214...
214	# Here we setup mapping for both the unmapped and mapped sections of the kernel.	214	# Here we setup mapping for both the unmapped and mapped sections of the kernel.
215	# For simplicity, we set only one 4M page for 0x00000000 and one for 0x80000000.	215	# For simplicity, we set only one 4M page for 0x00000000 and one for 0x80000000.
216	#	216	#
217	movl %cr4, %ecx	217	movl %cr4, %ecx
218	orl $(1<<4), %ecx	218	orl $(1<<4), %ecx
219	movl %ecx, %cr4 # turn PSE on	219	movl %ecx, %cr4 # turn PSE on
220		220
221	movl $((1<<7)\|(1<<0)), %eax	221	movl $((1<<7)\|(1<<0)), %eax
222	movl %eax, page_directory # mapping 0x00000000 => 0x00000000	222	movl %eax, page_directory # mapping 0x00000000 => 0x00000000
223		223
224	movl $(page_directory+2048), %edx	224	movl $(page_directory+2048), %edx
225	movl %eax, (%edx) # mapping 0x80000000 => 0x00000000	225	movl %eax, (%edx) # mapping 0x80000000 => 0x00000000
226		226
227	leal page_directory, %eax	227	leal page_directory, %eax
228	movl %eax, %cr3	228	movl %eax, %cr3
229		229
230	# turn paging on	230	# turn paging on

Subversion Repositories HelenOS

(root)/SPARTAN/trunk/arch/ia32/src/boot/boot.S – Rev 314 → 323