#
# Copyright (c) 2001-2004 Jakub Jermar
# Copyright (c) 2005-2006 Martin Decky
# All rights reserved.
#
# Redistribution and use in source and binary forms, with or without
# modification, are permitted provided that the following conditions
# are met:
#
# - Redistributions of source code must retain the above copyright
#   notice, this list of conditions and the following disclaimer.
# - Redistributions in binary form must reproduce the above copyright
#   notice, this list of conditions and the following disclaimer in the
#   documentation and/or other materials provided with the distribution.
# - The name of the author may not be used to endorse or promote products
#   derived from this software without specific prior written permission.
#
# THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
# IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
# OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
# IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
# INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
# NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
# DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
# THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
# (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
# THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
#

#include <arch/boot/boot.h>
#include <arch/boot/memmap.h>
#include <arch/mm/page.h>
#include <arch/pm.h>

#define START_STACK (BOOT_OFFSET - BOOT_STACK_SIZE)

.section K_TEXT_START, "ax"

.code32
.align 4
.global multiboot_image_start
multiboot_header:
	.long MULTIBOOT_HEADER_MAGIC
	.long MULTIBOOT_HEADER_FLAGS
	.long -(MULTIBOOT_HEADER_MAGIC + MULTIBOOT_HEADER_FLAGS)	# checksum
	.long multiboot_header
	.long unmapped_ktext_start
	.long 0
	.long 0
	.long multiboot_image_start
	
multiboot_image_start:
	movl $START_STACK, %esp			# initialize stack pointer
	lgdt KA2PA(bootstrap_gdtr)		# initialize Global Descriptor Table register

	movw $selector(KDATA_DES), %cx
	movw %cx, %es
	movw %cx, %fs
	movw %cx, %gs
	movw %cx, %ds					# kernel data + stack
	movw %cx, %ss
	
	jmpl $selector(KTEXT_DES), $multiboot_meeting_point
	multiboot_meeting_point:
	
	pushl %ebx							# save parameters from GRUB
	pushl %eax
	
#ifdef CONFIG_FB
	mov $vesa_init, %esi
	mov $VESA_INIT_SEGMENT << 4, %edi
	mov $e_vesa_init - vesa_init, %ecx
	cld
	rep movsb

	mov $VESA_INIT_SEGMENT << 4, %edi
	jmpl *%edi
	
	vesa_meeting_point:
	
	mov %esi, KA2PA(vesa_ph_addr)
	mov %di, KA2PA(vesa_height)
	shr $16, %edi
	mov %di, KA2PA(vesa_width)
	mov %bx, KA2PA(vesa_scanline)
	shr $16, %ebx
	mov %bx, KA2PA(vesa_bpp)
#endif	
	
	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
		
		jmp invalid_boot
		
	valid_boot:
		
		movl (%ebx), %eax						# ebx = physical address of struct multiboot_info
		
		bt $0, %eax								# mbi->flags[0] (mem_lower, mem_upper valid)
		jc mem_valid
			
			xorl %ecx, %ecx
			jmp mem_invalid
			
		mem_valid:
		movl 4(%ebx), %ecx						# mbi->mem_lower
		addl 8(%ebx), %ecx						# mbi->mem_upper
		
		mem_invalid:
		movl %ecx, e801memorysize
		
		bt $3, %eax								# mbi->flags[3] (mods_count, mods_addr valid)
		jc mods_valid
			
			xorl %ecx, %ecx
			movl %ecx, init
			jmp mods_end
		
		mods_valid:
		
		movl 20(%ebx), %ecx						# mbi->mods_count
		movl %ecx, init
		
		cmpl $0, %ecx
		je mods_end
		
		movl 24(%ebx), %esi						# mbi->mods_addr
		movl $init, %edi
		
		mods_loop:
		
			movl 0(%esi), %edx					# mods->mod_start
			addl $0x80000000, %edx
			movl %edx, 4(%edi)
			
			movl 4(%esi), %edx
			subl 0(%esi), %edx					# mods->mod_end - mods->mod_start
			movl %edx, 8(%edi)
			
			addl $16, %esi
			addl $8	, %edi
			
			loop mods_loop
			
		mods_end:
		
		bt $6, %eax								# mbi->flags[6] (mmap_length, mmap_addr valid)	
		jc mmap_valid
			
			xorl %edx, %edx
			jmp mmap_invalid
			
		mmap_valid:
		movl 44(%ebx), %ecx						# mbi->mmap_length
		movl 48(%ebx), %esi						# mbi->mmap_addr
		movl $e820table, %edi
		xorl %edx, %edx
		
		mmap_loop:
			cmpl $0, %ecx
			jle mmap_end
			
			movl 4(%esi), %eax					# mmap->base_addr_low
			movl %eax, (%edi)
			
			movl 8(%esi), %eax					# mmap->base_addr_high
			movl %eax, 4(%edi)
			
			movl 12(%esi), %eax					# mmap->length_low
			movl %eax, 8(%edi)
			
			movl 16(%esi), %eax					# mmap->length_high
			movl %eax, 12(%edi)
			
			movl 20(%esi), %eax					# mmap->type
			movl %eax, 16(%edi)
			
			movl (%esi), %eax					# mmap->size
			addl $0x4, %eax
			addl %eax, %esi
			subl %eax, %ecx
			addl $MEMMAP_E820_RECORD_SIZE, %edi
			incl %edx
			jmp mmap_loop
		
		mmap_end:
		
		mmap_invalid:
		movl %edx, e820counter
		
	invalid_boot:
	
#ifdef CONFIG_SMP
	
	# copy AP bootstrap routines below 1 MB
	
	movl $BOOT_OFFSET, %esi
	movl $AP_BOOT_OFFSET, %edi
	movl $_hardcoded_unmapped_size, %ecx
	cld
	rep movsb
	
#endif
	
	call main_bsp								# never returns

	cli
	hlt

.global map_kernel
map_kernel:
	#
	# Here we setup mapping for both the unmapped and mapped sections of the kernel.
	# For simplicity, we map the entire 4G space.
	#
	movl %cr4, %ecx
	orl $(1<<4), %ecx
	movl %ecx, %cr4							# turn PSE on
	
	movl $(page_directory+0), %esi
	movl $(page_directory+2048), %edi
	xorl %ecx, %ecx
	xorl %ebx, %ebx
0:
	movl $((1<<7)|(1<<0)), %eax
	orl %ebx, %eax
	movl %eax, (%esi,%ecx,4)					# mapping 0x00000000+%ecx*4M => 0x00000000+%ecx*4M
	movl %eax, (%edi,%ecx,4)					# mapping 0x80000000+%ecx*4M => 0x00000000+%ecx*4M
	addl $(4*1024*1024), %ebx

	incl %ecx
	cmpl $512, %ecx
	jl 0b

	movl %esi, %cr3
	
	# turn paging on
	movl %cr0, %ebx
	orl $(1<<31), %ebx
	movl %ebx, %cr0
	ret

#ifdef CONFIG_FB
vesa_init:
	jmp $selector(VESA_INIT_DES), $vesa_init_real - vesa_init
	
.code16
vesa_init_real:
	
	mov %cr0, %eax
	and $~1, %eax
	mov %eax, %cr0
	
	jmp $VESA_INIT_SEGMENT, $vesa_init_real2 - vesa_init
	
vesa_init_real2:
	
	mov $VESA_INIT_SEGMENT, %bx
	
	mov %bx, %es
	mov %bx, %fs
	mov %bx, %gs
	mov %bx, %ds
	mov %bx, %ss
	
	movl %esp, %eax
	movl $0x0000fffc, %esp
	movl $0x0000fffc, %ebp
	pushl %eax
	
#define VESA_INFO_SIZE 1024

#define VESA_MODE_LIST_PTR_OFFSET 14
#define VESA_MODE_WIDTH_OFFSET 18
#define VESA_MODE_HEIGHT_OFFSET 20
#define VESA_MODE_BPP_OFFSET 25
#define VESA_MODE_SCANLINE_OFFSET 16
#define VESA_MODE_PHADDR_OFFSET 40

#define VESA_END_OF_MODES 0xffff

#define VESA_OK 0x4f

#define VESA_GET_INFO 0x4f00
#define VESA_GET_MODE_INFO 0x4f01
#define VESA_SET_MODE 0x4f02

#define CONFIG_VESA_BPP_a 255

#if CONFIG_VESA_BPP == 24
#undef CONFIG_VESA_BPP_a
#define CONFIG_VESA_BPP_a 32
#endif

	mov $VESA_GET_INFO, %ax
	mov $e_vesa_init - vesa_init, %di
	push %di
	int $0x10
	
	pop %di
	cmp $VESA_OK, %al
	jnz 0f
	
	mov 2 + VESA_MODE_LIST_PTR_OFFSET(%di), %si
	mov %si, %gs
	mov VESA_MODE_LIST_PTR_OFFSET(%di), %si
	
	add $VESA_INFO_SIZE, %di

1:# Try next mode
	mov %gs:(%si), %cx
	cmp $VESA_END_OF_MODES, %cx
	jz 0f
	
	inc %si
	inc %si
	push %cx
	push %di
	push %si
	mov $VESA_GET_MODE_INFO, %ax
	int $0x10
	
	pop %si
	pop %di
	pop %cx
	cmp $VESA_OK, %al
	jnz 0f
	
	mov $CONFIG_VESA_WIDTH, %ax
	cmp VESA_MODE_WIDTH_OFFSET(%di), %ax
	jnz 1b
	
	mov $CONFIG_VESA_HEIGHT,%ax
	cmp VESA_MODE_HEIGHT_OFFSET(%di), %ax
	jnz 1b
	
	mov $CONFIG_VESA_BPP, %al
	cmp VESA_MODE_BPP_OFFSET(%di), %al
	jz 2f
	
	mov $CONFIG_VESA_BPP_a, %al
	cmp VESA_MODE_BPP_OFFSET(%di), %al
	jnz 1b
	
2:
	
	mov %cx, %bx
	or $0xc000, %bx
	push %di
	mov $VESA_SET_MODE, %ax
	int $0x10
	
	pop %di
	cmp $VESA_OK, %al
	jnz 0f
	
	mov VESA_MODE_PHADDR_OFFSET(%di), %esi
	mov VESA_MODE_WIDTH_OFFSET(%di), %ax
	shl $16, %eax
	mov VESA_MODE_HEIGHT_OFFSET(%di), %ax
	mov VESA_MODE_BPP_OFFSET(%di), %bl
	xor %bh, %bh
	shl $16, %ebx
	mov VESA_MODE_SCANLINE_OFFSET(%di), %bx
	mov %eax, %edi
	
8:	
	
	mov %cr0, %eax
	or $1, %eax
	mov %eax, %cr0
	
	jmp 9f
9:
	
	ljmpl $selector(KTEXT_DES), $(vesa_init_protect - vesa_init + VESA_INIT_SEGMENT << 4)

0:# No prefered mode found
	mov $0x111, %cx
	push %di
	push %cx
	mov $VESA_GET_MODE_INFO, %ax
	int $0x10
	
	pop %cx
	pop %di
	cmp $VESA_OK, %al
	jnz 1f
	jz 2b						# Force relative jump
	
1:
	mov $0x0003, %ax
	int $0x10
	mov $0xffffffff, %edi		# EGA text mode used, because of problems with VESA
	xor %ax, %ax
	jz 8b						# Force relative jump
	

.code32
vesa_init_protect:
	popl %esp

	movw $selector(KDATA_DES), %cx
	movw %cx, %es
	movw %cx, %fs
	movw %cx, %gs
	movw %cx, %ds					# kernel data + stack
	movw %cx, %ss
	
	jmpl $selector(KTEXT_DES), $vesa_meeting_point

.align 4
e_vesa_init:
#endif	

.section K_DATA_START, "aw", @progbits

.align 4096
page_directory:
	.space 4096, 0