CTAOS v2
This commit is contained in:
15
stage2/MAKE.BAT
Normal file
15
stage2/MAKE.BAT
Normal file
@@ -0,0 +1,15 @@
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@echo off
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set nasm_path=C:\nasm
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set djgpp_path=C:\DJGPP\bin
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set drive=A
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@echo on
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%nasm_path%\nasm.exe -f bin stage2.asm -o stage2.cta
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@echo off
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@echo.
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@echo Press any key to copy to %drive%:, or CTRL+C to stop.
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@pause >nul
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@echo off
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copy stage2.cta A:\stage2.cta
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103
stage2/a20.inc
Normal file
103
stage2/a20.inc
Normal file
@@ -0,0 +1,103 @@
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;********************************************
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; Enable A20 address line
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;
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; OS Development Series
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;********************************************
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%ifndef __A20_INC_67343546FDCC56AAB872_INCLUDED__
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%define __A20_INC_67343546FDCC56AAB872_INCLUDED__
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bits 16
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;----------------------------------------------
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; Enables a20 line through keyboard controller
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;----------------------------------------------
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EnableA20_KKbrd:
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cli
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push ax
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mov al, 0xdd ; send enable a20 address line command to controller
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out 0x64, al
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pop ax
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ret
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;--------------------------------------------
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; Enables a20 line through output port
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;--------------------------------------------
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EnableA20_KKbrd_Out:
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cli
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pusha
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call wait_input
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mov al,0xAD
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out 0x64,al ; disable keyboard
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call wait_input
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mov al,0xD0
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out 0x64,al ; tell controller to read output port
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call wait_output
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in al,0x60
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push eax ; get output port data and store it
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call wait_input
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mov al,0xD1
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out 0x64,al ; tell controller to write output port
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call wait_input
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pop eax
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or al,2 ; set bit 1 (enable a20)
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out 0x60,al ; write out data back to the output port
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call wait_input
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mov al,0xAE ; enable keyboard
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out 0x64,al
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call wait_input
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popa
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sti
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ret
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; wait for input buffer to be clear
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wait_input:
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in al,0x64
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test al,2
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jnz wait_input
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ret
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; wait for output buffer to be clear
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wait_output:
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in al,0x64
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test al,1
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jz wait_output
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ret
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;--------------------------------------
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; Enables a20 line through bios
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;--------------------------------------
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EnableA20_Bios:
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pusha
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mov ax, 0x2401
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int 0x15
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popa
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ret
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;-------------------------------------------------
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; Enables a20 line through system control port A
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;-------------------------------------------------
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EnableA20_SysControlA:
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push ax
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mov al, 2
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out 0x92, al
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pop ax
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ret
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%endif
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17
stage2/common.inc
Normal file
17
stage2/common.inc
Normal file
@@ -0,0 +1,17 @@
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%ifndef _COMMON_INC_INCLUDED
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%define _COMMON_INC_INCLUDED
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; where the kernel is to be loaded to in protected mode
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%define IMAGE_PMODE_BASE 0x100000
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; where the kernel is to be loaded to in real mode
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%define IMAGE_RMODE_BASE 0x3000
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; kernel name (Must be 11 bytes)
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ImageName db "KERNEL CTA"
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; size of kernel image in bytes
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ImageSize db 0
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%endif
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243
stage2/fat12.inc
Normal file
243
stage2/fat12.inc
Normal file
@@ -0,0 +1,243 @@
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;*******************************************************
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;
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; Fat12.inc
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; FAT12 filesystem for 3-1/2 floppies
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;
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; OS Development Series
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;*******************************************************
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%ifndef __FAT12_INC_67343546FDCC56AAB872_INCLUDED__
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%define __FAT12_INC_67343546FDCC56AAB872_INCLUDED__
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bits 16
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%include "Floppy16.inc" ; the erm.. floppy driver
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%define ROOT_OFFSET 0x2e00
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%define FAT_SEG 0x2c0
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%define ROOT_SEG 0x2e0
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;*******************************************
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; LoadRoot ()
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; - Load Root Directory Table to 0x7e00
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;*******************************************
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LoadRoot:
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pusha ; store registers
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push es
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; compute size of root directory and store in "cx"
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xor cx, cx ; clear registers
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xor dx, dx
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mov ax, 32 ; 32 byte directory entry
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mul WORD [bpbRootEntries] ; total size of directory
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div WORD [bpbBytesPerSector] ; sectors used by directory
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xchg ax, cx ; move into AX
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; compute location of root directory and store in "ax"
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mov al, BYTE [bpbNumberOfFATs] ; number of FATs
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mul WORD [bpbSectorsPerFAT] ; sectors used by FATs
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add ax, WORD [bpbReservedSectors]
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mov WORD [datasector], ax ; base of root directory
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add WORD [datasector], cx
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; read root directory into 0x7e00
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push word ROOT_SEG
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pop es
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mov bx, 0 ; copy root dir
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call ReadSectors ; read in directory table
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pop es
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popa ; restore registers and return
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ret
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;*******************************************
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; LoadFAT ()
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; - Loads FAT table to 0x7c00
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;
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; Parm/ ES:DI => Root Directory Table
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;*******************************************
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LoadFAT:
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pusha ; store registers
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push es
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; compute size of FAT and store in "cx"
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xor ax, ax
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mov al, BYTE [bpbNumberOfFATs] ; number of FATs
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mul WORD [bpbSectorsPerFAT] ; sectors used by FATs
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mov cx, ax
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; compute location of FAT and store in "ax"
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mov ax, WORD [bpbReservedSectors]
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; read FAT into memory (Overwrite our bootloader at 0x7c00)
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push word FAT_SEG
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pop es
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xor bx, bx
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call ReadSectors
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pop es
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popa ; restore registers and return
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ret
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;*******************************************
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; FindFile ()
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; - Search for filename in root table
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;
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; parm/ DS:SI => File name
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; ret/ AX => File index number in directory table. -1 if error
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;*******************************************
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FindFile:
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push cx ; store registers
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push dx
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push bx
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mov bx, si ; copy filename for later
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; browse root directory for binary image
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mov cx, WORD [bpbRootEntries] ; load loop counter
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mov di, ROOT_OFFSET ; locate first root entry at 1 MB mark
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cld ; clear direction flag
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.LOOP:
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push cx
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mov cx, 11 ; eleven character name. Image name is in SI
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mov si, bx ; image name is in BX
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push di
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rep cmpsb ; test for entry match
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pop di
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je .Found
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pop cx
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add di, 32 ; queue next directory entry
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loop .LOOP
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.NotFound:
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pop bx ; restore registers and return
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pop dx
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pop cx
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mov ax, -1 ; set error code
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ret
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.Found:
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pop ax ; return value into AX contains entry of file
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pop bx ; restore registers and return
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pop dx
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pop cx
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ret
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;*******************************************
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; LoadFile ()
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; - Load file
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; parm/ ES:SI => File to load
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; parm/ EBX:BP => Buffer to load file to
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; ret/ AX => -1 on error, 0 on success
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; ret/ CX => number of sectors read
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;*******************************************
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LoadFile:
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xor ecx, ecx ; size of file in sectors
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push ecx
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.FIND_FILE:
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push bx ; BX=>BP points to buffer to write to; store it for later
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push bp
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call FindFile ; find our file. ES:SI contains our filename
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cmp ax, -1
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jne .LOAD_IMAGE_PRE
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pop bp
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pop bx
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pop ecx
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mov ax, -1
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ret
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.LOAD_IMAGE_PRE:
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sub edi, ROOT_OFFSET
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sub eax, ROOT_OFFSET
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; get starting cluster
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push word ROOT_SEG ;root segment loc
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pop es
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mov dx, WORD [es:di + 0x001A]; DI points to file entry in root directory table. Refrence the table...
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mov WORD [cluster], dx ; file's first cluster
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pop bx ; get location to write to so we dont screw up the stack
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pop es
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push bx ; store location for later again
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push es
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call LoadFAT
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.LOAD_IMAGE:
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; load the cluster
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mov ax, WORD [cluster] ; cluster to read
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pop es ; bx:bp=es:bx
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pop bx
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call ClusterLBA
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xor cx, cx
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mov cl, BYTE [bpbSectorsPerCluster]
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call ReadSectors
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pop ecx
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inc ecx ; add one more sector to counter
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push ecx
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push bx
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push es
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mov ax, FAT_SEG ;start reading from fat
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mov es, ax
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xor bx, bx
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; get next cluster
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mov ax, WORD [cluster] ; identify current cluster
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mov cx, ax ; copy current cluster
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mov dx, ax
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shr dx, 0x0001 ; divide by two
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add cx, dx ; sum for (3/2)
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mov bx, 0 ;location of fat in memory
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add bx, cx
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mov dx, WORD [es:bx]
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test ax, 0x0001 ; test for odd or even cluster
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jnz .ODD_CLUSTER
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.EVEN_CLUSTER:
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and dx, 0000111111111111b ; take low 12 bits
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jmp .DONE
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.ODD_CLUSTER:
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shr dx, 0x0004 ; take high 12 bits
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.DONE:
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mov WORD [cluster], dx
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cmp dx, 0x0ff0 ; test for end of file marker
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jb .LOAD_IMAGE
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.SUCCESS:
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pop es
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pop bx
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pop ecx
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xor ax, ax
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ret
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%endif ;__FAT12_INC_67343546FDCC56AAB872_INCLUDED__
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117
stage2/floppy16.inc
Normal file
117
stage2/floppy16.inc
Normal file
@@ -0,0 +1,117 @@
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;*******************************************************
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;
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; Floppy16.inc
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; Floppy drive interface routines
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;
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; OS Development Series
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;*******************************************************
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%ifndef __FLOPPY16_INC_67343546FDCC56AAB872_INCLUDED__
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%define __FLOPPY16_INC_67343546FDCC56AAB872_INCLUDED__
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bits 16
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bpbOEM db "My OS "
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bpbBytesPerSector: DW 512
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bpbSectorsPerCluster: DB 1
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bpbReservedSectors: DW 1
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bpbNumberOfFATs: DB 2
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bpbRootEntries: DW 224
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bpbTotalSectors: DW 2880
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bpbMedia: DB 0xf0 ;; 0xF1
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bpbSectorsPerFAT: DW 9
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bpbSectorsPerTrack: DW 18
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bpbHeadsPerCylinder: DW 2
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bpbHiddenSectors: DD 0
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bpbTotalSectorsBig: DD 0
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bsDriveNumber: DB 0
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bsUnused: DB 0
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bsExtBootSignature: DB 0x29
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bsSerialNumber: DD 0xa0a1a2a3
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bsVolumeLabel: DB "MOS FLOPPY "
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bsFileSystem: DB "FAT12 "
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datasector dw 0x0000
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cluster dw 0x0000
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absoluteSector db 0x00
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absoluteHead db 0x00
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absoluteTrack db 0x00
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;************************************************;
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; Convert CHS to LBA
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; LBA = (cluster - 2) * sectors per cluster
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;************************************************;
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ClusterLBA:
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sub ax, 0x0002 ; zero base cluster number
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xor cx, cx
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mov cl, BYTE [bpbSectorsPerCluster] ; convert byte to word
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mul cx
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add ax, WORD [datasector] ; base data sector
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ret
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;************************************************;
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; Convert LBA to CHS
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; AX=>LBA Address to convert
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;
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; absolute sector = (logical sector / sectors per track) + 1
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; absolute head = (logical sector / sectors per track) MOD number of heads
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; absolute track = logical sector / (sectors per track * number of heads)
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;
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;************************************************;
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LBACHS:
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xor dx, dx ; prepare dx:ax for operation
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div WORD [bpbSectorsPerTrack] ; calculate
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inc dl ; adjust for sector 0
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mov BYTE [absoluteSector], dl
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xor dx, dx ; prepare dx:ax for operation
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div WORD [bpbHeadsPerCylinder] ; calculate
|
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mov BYTE [absoluteHead], dl
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mov BYTE [absoluteTrack], al
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ret
|
||||
|
||||
|
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;************************************************;
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; Reads a series of sectors
|
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; CX=>Number of sectors to read
|
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; AX=>Starting sector
|
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; ES:EBX=>Buffer to read to
|
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;************************************************;
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ReadSectors:
|
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.MAIN:
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mov di, 0x0005 ; five retries for error
|
||||
.SECTORLOOP:
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push ax
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push bx
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||||
push cx
|
||||
call LBACHS ; convert starting sector to CHS
|
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mov ah, 0x02 ; BIOS read sector
|
||||
mov al, 0x01 ; read one sector
|
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mov ch, BYTE [absoluteTrack] ; track
|
||||
mov cl, BYTE [absoluteSector] ; sector
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||||
mov dh, BYTE [absoluteHead] ; head
|
||||
mov dl, BYTE [bsDriveNumber] ; drive
|
||||
int 0x13 ; invoke BIOS
|
||||
jnc .SUCCESS ; test for read error
|
||||
xor ax, ax ; BIOS reset disk
|
||||
int 0x13 ; invoke BIOS
|
||||
dec di ; decrement error counter
|
||||
pop cx
|
||||
pop bx
|
||||
pop ax
|
||||
jnz .SECTORLOOP ; attempt to read again
|
||||
int 0x18
|
||||
.SUCCESS:
|
||||
pop cx
|
||||
pop bx
|
||||
pop ax
|
||||
add bx, WORD [bpbBytesPerSector] ; queue next buffer
|
||||
inc ax ; queue next sector
|
||||
loop .MAIN ; read next sector
|
||||
ret
|
||||
|
||||
%endif ;__FLOPPY16_INC_67343546FDCC56AAB872_INCLUDED__
|
||||
68
stage2/gdt.inc
Normal file
68
stage2/gdt.inc
Normal file
@@ -0,0 +1,68 @@
|
||||
|
||||
|
||||
;*************************************************
|
||||
; Gdt.inc
|
||||
; -GDT Routines
|
||||
;
|
||||
; OS Development Series
|
||||
;*************************************************
|
||||
|
||||
%ifndef __GDT_INC_67343546FDCC56AAB872_INCLUDED__
|
||||
%define __GDT_INC_67343546FDCC56AAB872_INCLUDED__
|
||||
|
||||
bits 16
|
||||
|
||||
;*******************************************
|
||||
; InstallGDT()
|
||||
; - Install our GDT
|
||||
;*******************************************
|
||||
|
||||
InstallGDT:
|
||||
|
||||
cli ; clear interrupts
|
||||
pusha ; save registers
|
||||
lgdt [toc] ; load GDT into GDTR
|
||||
sti ; enable interrupts
|
||||
popa ; restore registers
|
||||
ret ; All done!
|
||||
|
||||
;*******************************************
|
||||
; Global Descriptor Table (GDT)
|
||||
;*******************************************
|
||||
|
||||
gdt_data:
|
||||
dd 0 ; null descriptor
|
||||
dd 0
|
||||
|
||||
; gdt code: ; code descriptor
|
||||
dw 0FFFFh ; limit low
|
||||
dw 0 ; base low
|
||||
db 0 ; base middle
|
||||
db 10011010b ; access
|
||||
db 11001111b ; granularity
|
||||
db 0 ; base high
|
||||
|
||||
; gdt data: ; data descriptor
|
||||
dw 0FFFFh ; limit low (Same as code)10:56 AM 7/8/2007
|
||||
dw 0 ; base low
|
||||
db 0 ; base middle
|
||||
db 10010010b ; access
|
||||
db 11001111b ; granularity
|
||||
db 0 ; base high
|
||||
|
||||
end_of_gdt:
|
||||
toc:
|
||||
dw end_of_gdt - gdt_data - 1 ; limit (Size of GDT)
|
||||
dd gdt_data ; base of GDT
|
||||
|
||||
; give the descriptor offsets names
|
||||
|
||||
%define NULL_DESC 0
|
||||
%define CODE_DESC 0x8
|
||||
%define DATA_DESC 0x10
|
||||
|
||||
%endif ;__GDT_INC_67343546FDCC56AAB872_INCLUDED__
|
||||
|
||||
|
||||
|
||||
|
||||
158
stage2/stage2.asm
Normal file
158
stage2/stage2.asm
Normal file
@@ -0,0 +1,158 @@
|
||||
|
||||
;*******************************************************
|
||||
;
|
||||
; Stage2.asm
|
||||
; Stage2 Bootloader
|
||||
;
|
||||
; OS Development Series
|
||||
;*******************************************************
|
||||
|
||||
bits 16
|
||||
|
||||
; Remember the memory map-- 0x500 through 0x7bff is unused above the BIOS data area.
|
||||
; We are loaded at 0x500 (0x50:0)
|
||||
|
||||
org 0x500
|
||||
|
||||
jmp main ; go to start
|
||||
|
||||
;*******************************************************
|
||||
; Preprocessor directives
|
||||
;*******************************************************
|
||||
|
||||
%include "stdio.inc" ; basic i/o routines
|
||||
%include "Gdt.inc" ; Gdt routines
|
||||
%include "A20.inc" ; A20 enabling
|
||||
%include "Fat12.inc" ; FAT12 driver. Kinda :)
|
||||
%include "common.inc"
|
||||
|
||||
;*******************************************************
|
||||
; Data Section
|
||||
;*******************************************************
|
||||
|
||||
msgFailure db 0x0A, 0x0D, "FATAL ERROR: MISSING OR CORRUPT KERNEL.CTA", 0x0A, 0x0D, "Press any key to reboot...", 0x0D, 0x0A, 0x00
|
||||
|
||||
;*******************************************************
|
||||
; STAGE 2 ENTRY POINT
|
||||
;
|
||||
; -Store BIOS information
|
||||
; -Load Kernel
|
||||
; -Install GDT; go into protected mode (pmode)
|
||||
; -Jump to Stage 3
|
||||
;*******************************************************
|
||||
|
||||
main:
|
||||
|
||||
;-------------------------------;
|
||||
; Setup segments and stack ;
|
||||
;-------------------------------;
|
||||
|
||||
cli ; clear interrupts
|
||||
xor ax, ax ; null segments
|
||||
mov ds, ax
|
||||
mov es, ax
|
||||
mov ax, 0x0 ; stack begins at 0x9000-0xffff
|
||||
mov ss, ax
|
||||
mov sp, 0xFFFF
|
||||
sti ; enable interrupts
|
||||
|
||||
;-------------------------------;
|
||||
; Install our GDT ;
|
||||
;-------------------------------;
|
||||
|
||||
call InstallGDT ; install our GDT
|
||||
|
||||
;-------------------------------;
|
||||
; Enable A20 ;
|
||||
;-------------------------------;
|
||||
|
||||
call EnableA20_KKbrd_Out
|
||||
|
||||
;-------------------------------;
|
||||
; Initialize filesystem ;
|
||||
;-------------------------------;
|
||||
|
||||
call LoadRoot ; Load root directory table
|
||||
|
||||
;-------------------------------;
|
||||
; Load Kernel ;
|
||||
;-------------------------------;
|
||||
|
||||
mov ebx, 0 ; BX:BP points to buffer to load to
|
||||
mov bp, IMAGE_RMODE_BASE
|
||||
mov si, ImageName ; our file to load
|
||||
call LoadFile ; load our file
|
||||
mov dword [ImageSize], ecx ; save size of kernel
|
||||
cmp ax, 0 ; Test for success
|
||||
je EnterStage3 ; yep--onto Stage 3!
|
||||
mov si, msgFailure ; Nope--print error
|
||||
call Puts16
|
||||
mov ah, 0
|
||||
int 0x16 ; await keypress
|
||||
int 0x19 ; warm boot computer
|
||||
cli ; If we get here, something really went wong
|
||||
hlt
|
||||
|
||||
;-------------------------------;
|
||||
; Go into pmode ;
|
||||
;-------------------------------;
|
||||
|
||||
EnterStage3:
|
||||
|
||||
cli ; clear interrupts
|
||||
mov eax, cr0 ; set bit 0 in cr0--enter pmode
|
||||
or eax, 1
|
||||
mov cr0, eax
|
||||
|
||||
jmp CODE_DESC:Stage3 ; far jump to fix CS. Remember that the code selector is 0x8!
|
||||
|
||||
; Note: Do NOT re-enable interrupts! Doing so will triple fault!
|
||||
; We will fix this in Stage 3.
|
||||
|
||||
;******************************************************
|
||||
; ENTRY POINT FOR STAGE 3
|
||||
;******************************************************
|
||||
|
||||
bits 32
|
||||
|
||||
Stage3:
|
||||
|
||||
;-------------------------------;
|
||||
; Set registers ;
|
||||
;-------------------------------;
|
||||
|
||||
mov ax, DATA_DESC ; set data segments to data selector (0x10)
|
||||
mov ds, ax
|
||||
mov ss, ax
|
||||
mov es, ax
|
||||
mov esp, 90000h ; stack begins from 90000h
|
||||
|
||||
;-------------------------------;
|
||||
; Copy kernel to 1MB ;
|
||||
;-------------------------------;
|
||||
|
||||
CopyImage:
|
||||
mov eax, dword [ImageSize]
|
||||
movzx ebx, word [bpbBytesPerSector]
|
||||
mul ebx
|
||||
mov ebx, 4
|
||||
div ebx
|
||||
cld
|
||||
mov esi, IMAGE_RMODE_BASE
|
||||
mov edi, IMAGE_PMODE_BASE
|
||||
mov ecx, eax
|
||||
rep movsd ; copy image to its protected mode address
|
||||
|
||||
;---------------------------------------;
|
||||
; Execute Kernel ;
|
||||
;---------------------------------------;
|
||||
|
||||
jmp CODE_DESC:IMAGE_PMODE_BASE; jump to our kernel! Note: This assumes Kernel's entry point is at 1 MB
|
||||
|
||||
;---------------------------------------;
|
||||
; Stop execution ;
|
||||
;---------------------------------------;
|
||||
|
||||
cli
|
||||
hlt
|
||||
|
||||
BIN
stage2/stage2.cta
Normal file
BIN
stage2/stage2.cta
Normal file
Binary file not shown.
298
stage2/stdio.inc
Normal file
298
stage2/stdio.inc
Normal file
@@ -0,0 +1,298 @@
|
||||
|
||||
;*************************************************
|
||||
; stdio.inc
|
||||
; -Input/Output routines
|
||||
;
|
||||
; OS Development Series
|
||||
;*************************************************
|
||||
|
||||
%ifndef __STDIO_INC_67343546FDCC56AAB872_INCLUDED__
|
||||
%define __STDIO_INC_67343546FDCC56AAB872_INCLUDED__
|
||||
|
||||
|
||||
;==========================================================
|
||||
;
|
||||
; 16 Bit Real Mode Routines
|
||||
;==========================================================
|
||||
|
||||
|
||||
;************************************************;
|
||||
; Puts16 ()
|
||||
; -Prints a null terminated string
|
||||
; DS=>SI: 0 terminated string
|
||||
;************************************************;
|
||||
|
||||
bits 16
|
||||
|
||||
Puts16:
|
||||
pusha ; save registers
|
||||
.Loop1:
|
||||
lodsb ; load next byte from string from SI to AL
|
||||
or al, al ; Does AL=0?
|
||||
jz Puts16Done ; Yep, null terminator found-bail out
|
||||
mov ah, 0eh ; Nope-Print the character
|
||||
int 10h ; invoke BIOS
|
||||
jmp .Loop1 ; Repeat until null terminator found
|
||||
Puts16Done:
|
||||
popa ; restore registers
|
||||
ret ; we are done, so return
|
||||
|
||||
|
||||
;==========================================================
|
||||
;
|
||||
; 32 Bit Protected Mode Routines
|
||||
;==========================================================
|
||||
|
||||
bits 32
|
||||
|
||||
%define VIDMEM 0xB8000 ; video memory
|
||||
%define COLS 80 ; width and height of screen
|
||||
%define LINES 25
|
||||
%define CHAR_ATTRIB 63 ; character attribute (White text on light blue background)
|
||||
|
||||
_CurX db 0 ; current x/y location
|
||||
_CurY db 0
|
||||
|
||||
;**************************************************;
|
||||
; Putch32 ()
|
||||
; - Prints a character to screen
|
||||
; BL => Character to print
|
||||
;**************************************************;
|
||||
|
||||
Putch32:
|
||||
|
||||
pusha ; save registers
|
||||
mov edi, VIDMEM ; get pointer to video memory
|
||||
|
||||
;-------------------------------;
|
||||
; Get current position ;
|
||||
;-------------------------------;
|
||||
|
||||
xor eax, eax ; clear eax
|
||||
|
||||
;--------------------------------
|
||||
; Remember: currentPos = x + y * COLS! x and y are in _CurX and _CurY.
|
||||
; Because there are two bytes per character, COLS=number of characters in a line.
|
||||
; We have to multiply this by 2 to get number of bytes per line. This is the screen width,
|
||||
; so multiply screen with * _CurY to get current line
|
||||
;--------------------------------
|
||||
|
||||
mov ecx, COLS*2 ; Mode 7 has 2 bytes per char, so its COLS*2 bytes per line
|
||||
mov al, byte [_CurY] ; get y pos
|
||||
mul ecx ; multiply y*COLS
|
||||
push eax ; save eax--the multiplication
|
||||
|
||||
;--------------------------------
|
||||
; Now y * screen width is in eax. Now, just add _CurX. But, again remember that _CurX is relative
|
||||
; to the current character count, not byte count. Because there are two bytes per character, we
|
||||
; have to multiply _CurX by 2 first, then add it to our screen width * y.
|
||||
;--------------------------------
|
||||
|
||||
mov al, byte [_CurX] ; multiply _CurX by 2 because it is 2 bytes per char
|
||||
mov cl, 2
|
||||
mul cl
|
||||
pop ecx ; pop y*COLS result
|
||||
add eax, ecx
|
||||
|
||||
;-------------------------------
|
||||
; Now eax contains the offset address to draw the character at, so just add it to the base address
|
||||
; of video memory (Stored in edi)
|
||||
;-------------------------------
|
||||
|
||||
xor ecx, ecx
|
||||
add edi, eax ; add it to the base address
|
||||
|
||||
;-------------------------------;
|
||||
; Watch for new line ;
|
||||
;-------------------------------;
|
||||
|
||||
cmp bl, 0x0A ; is it a newline character?
|
||||
je .Row ; yep--go to next row
|
||||
|
||||
;-------------------------------;
|
||||
; Print a character ;
|
||||
;-------------------------------;
|
||||
|
||||
mov dl, bl ; Get character
|
||||
mov dh, CHAR_ATTRIB ; the character attribute
|
||||
mov word [edi], dx ; write to video display
|
||||
|
||||
;-------------------------------;
|
||||
; Update next position ;
|
||||
;-------------------------------;
|
||||
|
||||
inc byte [_CurX] ; go to next character
|
||||
; cmp byte [_CurX], COLS ; are we at the end of the line?
|
||||
; je .Row ; yep-go to next row
|
||||
jmp .done ; nope, bail out
|
||||
|
||||
;-------------------------------;
|
||||
; Go to next row ;
|
||||
;-------------------------------;
|
||||
|
||||
.Row:
|
||||
mov byte [_CurX], 0 ; go back to col 0
|
||||
inc byte [_CurY] ; go to next row
|
||||
|
||||
;-------------------------------;
|
||||
; Restore registers & return ;
|
||||
;-------------------------------;
|
||||
|
||||
.done:
|
||||
popa ; restore registers and return
|
||||
ret
|
||||
|
||||
;**************************************************;
|
||||
; Puts32 ()
|
||||
; - Prints a null terminated string
|
||||
; parm\ EBX = address of string to print
|
||||
;**************************************************;
|
||||
|
||||
Puts32:
|
||||
|
||||
;-------------------------------;
|
||||
; Store registers ;
|
||||
;-------------------------------;
|
||||
|
||||
pusha ; save registers
|
||||
push ebx ; copy the string address
|
||||
pop edi
|
||||
|
||||
.loop:
|
||||
|
||||
;-------------------------------;
|
||||
; Get character ;
|
||||
;-------------------------------;
|
||||
|
||||
mov bl, byte [edi] ; get next character
|
||||
cmp bl, 0 ; is it 0 (Null terminator)?
|
||||
je .done ; yep-bail out
|
||||
|
||||
;-------------------------------;
|
||||
; Print the character ;
|
||||
;-------------------------------;
|
||||
|
||||
call Putch32 ; Nope-print it out
|
||||
|
||||
;-------------------------------;
|
||||
; Go to next character ;
|
||||
;-------------------------------;
|
||||
|
||||
inc edi ; go to next character
|
||||
jmp .loop
|
||||
|
||||
.done:
|
||||
|
||||
;-------------------------------;
|
||||
; Update hardware cursor ;
|
||||
;-------------------------------;
|
||||
|
||||
; Its more efficiant to update the cursor after displaying
|
||||
; the complete string because direct VGA is slow
|
||||
|
||||
mov bh, byte [_CurY] ; get current position
|
||||
mov bl, byte [_CurX]
|
||||
call MovCur ; update cursor
|
||||
|
||||
popa ; restore registers, and return
|
||||
ret
|
||||
|
||||
;**************************************************;
|
||||
; MoveCur ()
|
||||
; - Update hardware cursor
|
||||
; parm/ bh = Y pos
|
||||
; parm/ bl = x pos
|
||||
;**************************************************;
|
||||
|
||||
bits 32
|
||||
|
||||
MovCur:
|
||||
|
||||
pusha ; save registers (aren't you getting tired of this comment?)
|
||||
|
||||
;-------------------------------;
|
||||
; Get current position ;
|
||||
;-------------------------------;
|
||||
|
||||
; Here, _CurX and _CurY are relitave to the current position on screen, not in memory.
|
||||
; That is, we don't need to worry about the byte alignment we do when displaying characters,
|
||||
; so just follow the forumla: location = _CurX + _CurY * COLS
|
||||
|
||||
xor eax, eax
|
||||
mov ecx, COLS
|
||||
mov al, bh ; get y pos
|
||||
mul ecx ; multiply y*COLS
|
||||
add al, bl ; Now add x
|
||||
mov ebx, eax
|
||||
|
||||
;--------------------------------------;
|
||||
; Set low byte index to VGA register ;
|
||||
;--------------------------------------;
|
||||
|
||||
mov al, 0x0f
|
||||
mov dx, 0x03D4
|
||||
out dx, al
|
||||
|
||||
mov al, bl
|
||||
mov dx, 0x03D5
|
||||
out dx, al ; low byte
|
||||
|
||||
;---------------------------------------;
|
||||
; Set high byte index to VGA register ;
|
||||
;---------------------------------------;
|
||||
|
||||
xor eax, eax
|
||||
|
||||
mov al, 0x0e
|
||||
mov dx, 0x03D4
|
||||
out dx, al
|
||||
|
||||
mov al, bh
|
||||
mov dx, 0x03D5
|
||||
out dx, al ; high byte
|
||||
|
||||
popa
|
||||
ret
|
||||
|
||||
;**************************************************;
|
||||
; ClrScr32 ()
|
||||
; - Clears screen
|
||||
;**************************************************;
|
||||
|
||||
bits 32
|
||||
|
||||
ClrScr32:
|
||||
|
||||
pusha
|
||||
cld
|
||||
mov edi, VIDMEM
|
||||
mov cx, 2000
|
||||
mov ah, CHAR_ATTRIB
|
||||
mov al, ' '
|
||||
rep stosw
|
||||
|
||||
mov byte [_CurX], 0
|
||||
mov byte [_CurY], 0
|
||||
popa
|
||||
ret
|
||||
|
||||
;**************************************************;
|
||||
; GotoXY ()
|
||||
; - Set current X/Y location
|
||||
; parm\ AL=X position
|
||||
; parm\ AH=Y position
|
||||
;**************************************************;
|
||||
|
||||
bits 32
|
||||
|
||||
GotoXY:
|
||||
pusha
|
||||
mov [_CurX], al ; just set the current position
|
||||
mov [_CurY], ah
|
||||
popa
|
||||
ret
|
||||
|
||||
|
||||
|
||||
|
||||
%endif ;__STDIO_INC_67343546FDCC56AAB872_INCLUDED__
|
||||
Reference in New Issue
Block a user