diff options
Diffstat (limited to 'arch/i386/init.s')
| -rw-r--r-- | arch/i386/init.s | 49 |
1 files changed, 49 insertions, 0 deletions
diff --git a/arch/i386/init.s b/arch/i386/init.s new file mode 100644 index 0000000..ad329bb --- /dev/null +++ b/arch/i386/init.s @@ -0,0 +1,49 @@ +.section .stack, "aw", @nobits +.global k_stack +.align 16 /* Stack on x86 must be 16-byte aligned according to System V ABI */ +k_stack_bottom: + .skip 16 * 1024 /* 16 kByte */ +k_stack: + +.section .pages, "aw", @nobits +.align 4096 +.global k_pagedir +k_pagedir: .skip 1024 * 4 +.global k_ptable0x300 +k_ptable0x300: .skip 1024 * 4 + +.section .text +.global k_init +.extern kmain +.extern gdt_install +.extern idt_install +k_init: + # kernel entry point, higher half + + # unmap the identity mapping as its no longer necessary + movl $0, k_pagedir + 0 * 4 + mov %cr3, %ecx # reload cr3 to force a TLB flush + mov %ecx, %cr3 + + # zero out the stack + mov $4096, %ecx # loop counter + mov $k_stack_bottom, %edi # start from the bottom + xor %edx, %edx # clear %edx +1: movl %edx, (%edi) # store %edx into address in %edi + addl $4, %edi # point to next address + loop 1b # loop according to %ecx + + mov $k_stack, %esp # point stack pointer to the stack + + # hardware init + call gdt_install # Global Descriptor Table + call idt_install # Interrupt Descriptor Table + + # jump into kernel + call kmain + + /* If the system has nothing more to do, put it in an infinite loop */ + cli # disable interrupts +h: hlt # wait for interrupt + jmp h # continue waiting for interrupt + |