Remove memory/mcb management
This commit is contained in:
parent
b21acb076c
commit
56f01a0888
15
main.asm
15
main.asm
@ -3,15 +3,14 @@ cpu 8086
|
||||
org 0x0100
|
||||
jmp main
|
||||
|
||||
str1:
|
||||
db "Hello!", 0
|
||||
|
||||
main:
|
||||
mov ax,0x1000
|
||||
mov bx,0x0000
|
||||
mov cx,0x0800
|
||||
call mtab_set
|
||||
call mtab_dump
|
||||
mov ax,cs
|
||||
mov ds,ax
|
||||
mov si,str1
|
||||
call kprintf
|
||||
ret
|
||||
|
||||
%include "kprintf.asm"
|
||||
|
||||
; mem MUST be last because it will write after itself
|
||||
%include "mem.asm"
|
||||
|
237
mem.asm
237
mem.asm
@ -1,237 +0,0 @@
|
||||
; memory type is enum
|
||||
; 00 - free
|
||||
; 01 - unknown
|
||||
; 02 - allocated by us
|
||||
; 03 - reserved, like BIOS code or tables for the cpu
|
||||
; 04 - unusable
|
||||
|
||||
; return the addr of the mtab
|
||||
; out: es:bx
|
||||
mtab_ref:
|
||||
push cs
|
||||
pop es
|
||||
mov bx,mtab
|
||||
ret
|
||||
|
||||
; finds a place for a new item in the mm table
|
||||
; this detects 'empty' slots by the size field being zero
|
||||
; in: ds:si: pointer to first mtab item
|
||||
; out: bx: offset for empty slot
|
||||
mtab_alloc:
|
||||
push ax
|
||||
call mtab_ref
|
||||
.loop:
|
||||
cmp WORD [es:bx],0x0000
|
||||
je .end
|
||||
add bx,0x0010
|
||||
jmp .loop
|
||||
.end:
|
||||
pop ax
|
||||
ret
|
||||
|
||||
; splits a mtab item at offset
|
||||
; in: ds:si: pointer mtab item
|
||||
; ax: split position in 16 byte blocks
|
||||
; out: ds:si: pointer to lower half
|
||||
; ds:di: pointer to upper half
|
||||
mtab_split:
|
||||
push cx ; remaining memory block length
|
||||
mov cx,[ds:si]
|
||||
|
||||
mov [ds:si],ax ; this resizes the first item
|
||||
sub cx, ax
|
||||
|
||||
push bx
|
||||
call mtab_alloc
|
||||
mov di,bx
|
||||
pop bx
|
||||
|
||||
push si ; backup because movsw increments them
|
||||
push di ; ^
|
||||
push cx ; counter for movsb
|
||||
mov es,ds
|
||||
mov cx,0x08 ; 8 words = 16 bytes
|
||||
rep movsw ; repeat cx times
|
||||
pop cx
|
||||
pop di
|
||||
pop si
|
||||
|
||||
mov [ds:di],cx
|
||||
|
||||
pop cx
|
||||
ret
|
||||
|
||||
; in: ax: segment
|
||||
; bh: task id (0 for non-task memory)
|
||||
; bl: memory type (see enum at top of file)
|
||||
; cx: number of 16-byte blocks
|
||||
mtab_set:
|
||||
push ds
|
||||
push cx ; length of current item
|
||||
push dx ; cumulative position
|
||||
push bx ; pointer to mtab item
|
||||
|
||||
call mtab_ref
|
||||
mov dx,0x0000
|
||||
push bx ; use as iterator, restoring base value afterwards
|
||||
.findbase: ; we pick the mtab item where our segment lies in
|
||||
mov cx,[es:bx]
|
||||
add dx,cx
|
||||
cmp dx,ax
|
||||
jnbe .dupbase
|
||||
add bx,0x0010
|
||||
jmp .findbase
|
||||
.dupbase: ; we duplicate it, so we potentially have one after and one before our new item
|
||||
mov si,bx
|
||||
call mtab_alloc
|
||||
mov di,bx
|
||||
pop bx
|
||||
|
||||
push si ; backup because movsw increments them
|
||||
push di ; ^
|
||||
push cx ; counter for movsb
|
||||
mov cx,0x08 ; a mtab item is 8 words = 16 bytes
|
||||
push es
|
||||
pop ds
|
||||
rep movsw
|
||||
pop cx
|
||||
pop di
|
||||
pop si
|
||||
.resizebase1:
|
||||
push ax ; size = [Segment ax] - ([End addr dx] - [Length cx])
|
||||
sub ax,dx
|
||||
add ax,cx
|
||||
mov [si],ax
|
||||
pop ax
|
||||
.resizebase2:
|
||||
push dx
|
||||
sub dx,ax
|
||||
mov [di],dx
|
||||
pop dx
|
||||
.insert:
|
||||
push bx
|
||||
call mtab_alloc
|
||||
mov dx,bx
|
||||
pop bx
|
||||
.base1_link:
|
||||
push ax
|
||||
mov ax,dx
|
||||
sub ax,bx ; addr are relative to mtab start
|
||||
mov [si+02],ax
|
||||
pop ax
|
||||
.new_link:
|
||||
push ax
|
||||
mov ax,di
|
||||
sub ax,bx ; addr are relative to mtab start
|
||||
mov di,dx
|
||||
mov [di+02],ax
|
||||
pop ax
|
||||
|
||||
pop bx
|
||||
mov [di+04],bx
|
||||
|
||||
pop dx
|
||||
pop cx
|
||||
|
||||
pop ds
|
||||
ret
|
||||
|
||||
mtab_dump:
|
||||
push cs
|
||||
pop ds
|
||||
mov cx,0x0000
|
||||
mov bp,mtab
|
||||
mov si,0x0000
|
||||
|
||||
.loop:
|
||||
push si
|
||||
|
||||
mov ax, bp
|
||||
add ax, si
|
||||
add ax, 0x06
|
||||
push ax
|
||||
|
||||
mov al,[bp+si+0x05]
|
||||
push ax ; task id
|
||||
|
||||
mov al,[bp+si+0x04]
|
||||
push bp
|
||||
push si
|
||||
mov bp,.typechar
|
||||
and ax,0x00FF
|
||||
mov si,ax
|
||||
mov al,[bp+si]
|
||||
pop si
|
||||
pop bp
|
||||
push ax ; memory type
|
||||
|
||||
mov bx,cx
|
||||
add cx,[bp+si+0x00]
|
||||
mov ax,cx
|
||||
dec ax
|
||||
push ax ; end addr
|
||||
push bx ; start addr
|
||||
|
||||
mov si,.linefmt
|
||||
call kprintf
|
||||
|
||||
pop ax
|
||||
pop ax
|
||||
pop ax
|
||||
pop ax
|
||||
pop ax
|
||||
pop si
|
||||
|
||||
; look for next line
|
||||
mov ax,[bp+si+0x02]
|
||||
test ax,0xFFFF
|
||||
mov si,ax
|
||||
jnz .loop
|
||||
ret
|
||||
.linefmt:
|
||||
db "%X0 %XF %c %x %s", 0
|
||||
.typechar:
|
||||
db "F?ARU", 0
|
||||
|
||||
; pre-filled table for memory management
|
||||
align 16
|
||||
mtab:
|
||||
; interrupt vector table
|
||||
dw 0x0040
|
||||
dw 0x0010
|
||||
db 3
|
||||
db 0
|
||||
db "IVT", 0
|
||||
align 16
|
||||
; bios data area (writes here during runtime)
|
||||
dw 0x0010
|
||||
dw 0x0020
|
||||
db 3
|
||||
db 0
|
||||
db "BDA", 0
|
||||
align 16
|
||||
dw 0x9FB0
|
||||
dw 0x0030
|
||||
db 0
|
||||
db 0
|
||||
db 0
|
||||
align 16
|
||||
dw 0x5000
|
||||
dw 0x0040
|
||||
db 4
|
||||
db 0
|
||||
db 0
|
||||
align 16
|
||||
dw 0x1000
|
||||
dw 0x0000
|
||||
db 4
|
||||
db 0
|
||||
db "BIOS ROM", 0
|
||||
align 16
|
||||
dw 0x0000
|
||||
align 16
|
||||
dw 0x0000
|
||||
align 16
|
||||
dw 0x0000
|
||||
align 16
|
||||
dw 0x0000
|
Loading…
Reference in New Issue
Block a user