diff options
Diffstat (limited to 'entryother.S')
| -rw-r--r-- | entryother.S | 93 |
1 files changed, 0 insertions, 93 deletions
diff --git a/entryother.S b/entryother.S deleted file mode 100644 index a3b6dc2..0000000 --- a/entryother.S +++ /dev/null @@ -1,93 +0,0 @@ -#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. -# -# Startothers (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 entrypgdir in start-12. -# -# This code combines elements of bootasm.S and entry.S. - -.code16 -.globl start -start: - cli - - # Zero data segment registers DS, ES, and SS. - xorw %ax,%ax - movw %ax,%ds - movw %ax,%es - movw %ax,%ss - - # Switch from real to protected mode. Use a bootstrap GDT that makes - # virtual addresses map directly to physical addresses so that the - # effective memory map doesn't change during the transition. - lgdt gdtdesc - movl %cr0, %eax - orl $CR0_PE, %eax - movl %eax, %cr0 - - # Complete the transition to 32-bit protected mode by using a long jmp - # to reload %cs and %eip. The segment descriptors are set up with no - # translation, so that the mapping is still the identity mapping. - ljmpl $(SEG_KCODE<<3), $(start32) - -//PAGEBREAK! -.code32 # Tell assembler to generate 32-bit code now. -start32: - # Set up the protected-mode data segment registers - movw $(SEG_KDATA<<3), %ax # Our data segment selector - movw %ax, %ds # -> DS: Data Segment - movw %ax, %es # -> ES: Extra Segment - movw %ax, %ss # -> SS: Stack Segment - movw $0, %ax # Zero segments not ready for use - movw %ax, %fs # -> FS - movw %ax, %gs # -> GS - - # Turn on page size extension for 4Mbyte pages - movl %cr4, %eax - orl $(CR4_PSE), %eax - movl %eax, %cr4 - # Use entrypgdir 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 - |