2019-04-01 01:18:48 +00:00
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.set ALIGN, 1<<0
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.set MEMINFO, 1<<1
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.set FLAGS, ALIGN | MEMINFO
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.set MAGIC, 0x1BADB002
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.set CHECKSUM, -(MAGIC + FLAGS)
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.section .multiboot
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.align 4
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.long MAGIC
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.long FLAGS
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.long CHECKSUM
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2019-04-06 19:00:11 +00:00
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# C stack startup
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2019-04-01 01:18:48 +00:00
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.section .bss
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.align 16
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stack_bottom:
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.skip 16384
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stack_top:
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2019-04-06 19:00:11 +00:00
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# start function - calls kernel_main
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2019-04-01 01:18:48 +00:00
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.section .text
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.global _start
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.type _start, @function
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2019-04-01 11:21:00 +00:00
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2019-04-01 01:18:48 +00:00
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_start:
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movl $stack_top, %esp
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call _init
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call kernel_main
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cli
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1: hlt
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jmp 1b
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2019-04-06 19:25:31 +00:00
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.size _start, . - _start
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# GDT segment register setup
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.global gdt_flush
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.extern gp
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gdt_flush:
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lgdt (gp) #load the GDT with the special pointer
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mov %eax,0x10 #offset from GDT to data segment
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mov %eax, %ds
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mov %eax, %es
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mov %eax, %fs
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mov %eax, %gs
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mov %eax, %ss
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pushl 12(%esp)
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push $flush2
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ljmp *(%esp) #long jump
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flush2:
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2019-04-07 12:16:53 +00:00
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ret #return to c code
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.global idt_load
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.extern idtp
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idt_load:
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lidt (idtp)
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ret
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