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Import backup from 2005-11-01

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This commit is contained in:
Josh Holtrop 2005-11-01 22:00:00 -05:00
parent 79ca453f66
commit 7daa1c5336
3 changed files with 37 additions and 18 deletions
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27
kernel/boot.asm
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@ -89,10 +89,7 @@ segmented_start:
mov ecx, _rm_params ; put real mode params here (video mode etc...)
sub ecx, VIRT_OFFSET
mov eax, cr0
and eax, 0x7FFFFFFE ; leave PM
mov cr0, eax
jmp 0x0:0x5010 ; jump to rmmod
jmp 0xC0005010 ; jump to rmmod
;Next we enable paging with the first 4mb mapped 1:1 virtual:physical
; and with the 4mb starting at 0xC000_0000 mapped to the first 4mb physical.
@ -191,12 +188,12 @@ idle_loop: ; system idle loop
gdtrbs32:
dw gdt_endbs32-gdtbs32-1
dd gdtbs32-VIRT_OFFSET
gdtbs32: ;null descriptor
gdtbs32: ; 0 = null descriptor
dd 0
dd 0
;a base of 0x4000_0000, when added to 0xC000_0000 will produce 0x0000_0000 physical before paging in effect
KERNEL_CODE_BS32 equ $-gdtbs32
KERNEL_CODE_BS32 equ $-gdtbs32 ; 8
db 0xff ;limit 7:0
db 0xff ;limit 15:8
db 0x00 ;base 7:0
@ -206,7 +203,7 @@ KERNEL_CODE_BS32 equ $-gdtbs32
db 0xcf ;flags / limit 19:16
db 0x40 ;base 31:24
KERNEL_DATA_BS32 equ $-gdtbs32
KERNEL_DATA_BS32 equ $-gdtbs32 ; 16
db 0xff ;limit 7:0
db 0xff ;limit 15:8
db 0x00 ;base 7:0
@ -216,6 +213,22 @@ KERNEL_DATA_BS32 equ $-gdtbs32
db 0xcf ;flags / limit 19:16
db 0x40 ;base 31:24
KERNEL_CODE_BS6_ equ $-gdtbs32 ; 24
dw 0xffff ;limit 15:0
dw 0x0000 ;base 15:0
db 0x00 ;base 23:16
db 0x9A ;access ([P][DPL][1][Executable][Direction/Conforming][Writable/Readable][A])
db 0x00 ;flags ([G][D/B][0][0]) / limit 19:16
db 0x00 ;base 31:24
KERNEL_DATA_BS16 equ $-gdtbs32 ; 32
dw 0xffff ;limit 15:0
dw 0x0000 ;base 15:0
db 0x00 ;base 23:16
db 0x92 ;access ([P][DPL][1][Executable][Direction/Conforming][Writable/Readable][A])
db 0x00 ;flags ([G][D/B][0][0]) / limit 19:16
db 0x00 ;base 31:24
gdt_endbs32:
%include "gdt.inc"

12
kernel/gdt.inc
View File

@ -6,11 +6,11 @@
gdtr:
dw gdt_end-gdt-1
dd GDT_V
gdt:
gdt: ; 0
dd 0
dd 0
KERNEL_CODE equ $-gdt
KERNEL_CODE equ $-gdt ; 8
dw 0xffff ;limit 15:0
dw 0x0000 ;base 15:0
db 0x00 ;base 23:16
@ -18,7 +18,7 @@ KERNEL_CODE equ $-gdt
db 0xCF ;flags ([G][D/B][0][0]) / limit 19:16
db 0x00 ;base 31:24
KERNEL_DATA equ $-gdt
KERNEL_DATA equ $-gdt ; 16
dw 0xffff ;limit 15:0
dw 0x0000 ;base 15:0
db 0x00 ;base 23:16
@ -27,7 +27,7 @@ KERNEL_DATA equ $-gdt
db 0x00 ;base 31:24
USER_CODE equ $-gdt
USER_CODE equ $-gdt ; 24
dw 0xffff ;limit 15:0
dw 0x0000 ;base 15:0
db 0x00 ;base 23:16
@ -35,7 +35,7 @@ USER_CODE equ $-gdt
db 0xCF ;flags ([G][D/B][0][0]) / limit 19:16
db 0x00 ;base 31:24
USER_DATA equ $-gdt
USER_DATA equ $-gdt ; 32
dw 0xffff ;limit 15:0
dw 0x0000 ;base 15:0
db 0x00 ;base 23:16
@ -43,7 +43,7 @@ USER_DATA equ $-gdt
db 0xCF ;flags ([G][D/B][0][0]) / limit 19:16
db 0x00 ;base 31:24
TSS0_SEG equ $-gdt
TSS0_SEG equ $-gdt ; 40
dw 0x67 ;limit 15:0
dw 0 ;base 15:0
db 0 ;base 23:16

16
rmmod/rmmod.asm
View File

@ -10,7 +10,7 @@
; the bootstrap process will jump us to 0x0:0x5010 so we'd better be ready for it
[org 0x5000]
[bits 16]
[bits 32]
;HOS module header, better be 16 bytes!
dd 0x4D534F48 ; magic identifier "HOSM"
dd 1 ; real mode module
@ -20,10 +20,16 @@
; ebx = return address
; ecx = where to store real mode parameter table
start:
jmp blah
blah:
jmp $
jmp 0:start_refreshed
jmp 24:start_pm16
[bits 16]
start_pm16: ; in 16-bit protected mode
mov ax, 32
mov ss, ax
mov eax, cr0
and eax, 0x7FFFFFFE
mov cr0, eax ; leave PM
jmp 0:start_refreshed ; enter RM
%include "conio.inc"
%include "vesa.inc"