87 lines
2 KiB
ArmAsm
87 lines
2 KiB
ArmAsm
#include "asm.h"
|
|
#include "memlayout.h"
|
|
#include "mmu.h"
|
|
|
|
# Each non-boot CPU ("AP") is started up in response to a STARTUP
|
|
# IPI from the boot CPU. Section B.4.2 of the Multi-Processor
|
|
# Specification says that the AP will start in real mode with CS:IP
|
|
# set to XY00:0000, where XY is an 8-bit value sent with the
|
|
# STARTUP. Thus this code must start at a 4096-byte boundary.
|
|
#
|
|
# Because this code sets DS to zero, it must sit
|
|
# at an address in the low 2^16 bytes.
|
|
#
|
|
# Bootothers (in main.c) sends the STARTUPs one at a time.
|
|
# It copies this code (start) at 0x7000. It puts the address of
|
|
# a newly allocated per-core stack in start-4,the address of the
|
|
# place to jump to (mpenter) in start-8, and the physical address
|
|
# of enterpgdir in start-12.
|
|
#
|
|
# This code is identical to bootasm.S except:
|
|
# - it does not need to enable A20
|
|
# - it uses the address at start-4, start-8, and start-12
|
|
|
|
.code16
|
|
.globl start
|
|
start:
|
|
cli
|
|
|
|
xorw %ax,%ax
|
|
movw %ax,%ds
|
|
movw %ax,%es
|
|
movw %ax,%ss
|
|
|
|
lgdt gdtdesc
|
|
movl %cr0, %eax
|
|
orl $CR0_PE, %eax
|
|
movl %eax, %cr0
|
|
|
|
//PAGEBREAK!
|
|
ljmpl $(SEG_KCODE<<3), $(start32)
|
|
|
|
.code32
|
|
start32:
|
|
movw $(SEG_KDATA<<3), %ax
|
|
movw %ax, %ds
|
|
movw %ax, %es
|
|
movw %ax, %ss
|
|
movw $0, %ax
|
|
movw %ax, %fs
|
|
movw %ax, %gs
|
|
|
|
# Turn on page size extension for 4Mbyte pages
|
|
movl %cr4, %eax
|
|
orl $(CR4_PSE), %eax
|
|
movl %eax, %cr4
|
|
# Use enterpgdir as our initial page table
|
|
movl (start-12), %eax
|
|
movl %eax, %cr3
|
|
# Turn on paging.
|
|
movl %cr0, %eax
|
|
orl $(CR0_PE|CR0_PG|CR0_WP), %eax
|
|
movl %eax, %cr0
|
|
|
|
# Switch to the stack allocated by startothers()
|
|
movl (start-4), %esp
|
|
# Call mpenter()
|
|
call *(start-8)
|
|
|
|
movw $0x8a00, %ax
|
|
movw %ax, %dx
|
|
outw %ax, %dx
|
|
movw $0x8ae0, %ax
|
|
outw %ax, %dx
|
|
spin:
|
|
jmp spin
|
|
|
|
.p2align 2
|
|
gdt:
|
|
SEG_NULLASM
|
|
SEG_ASM(STA_X|STA_R, 0, 0xffffffff)
|
|
SEG_ASM(STA_W, 0, 0xffffffff)
|
|
|
|
|
|
gdtdesc:
|
|
.word (gdtdesc - gdt - 1)
|
|
.long gdt
|
|
|