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This commit is contained in:
Christoph Urlacher
2022-07-16 01:01:58 +02:00
parent 35a5d7f9db
commit f41eda0215
1 changed files with 251 additions and 161 deletions
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412
c_os/kernel/BIOS.cc
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@ -8,24 +8,23 @@
* Autor: Michael Schoettner, 29.11.2018 *
*****************************************************************************/
#include "kernel/Globals.h"
#include "kernel/BIOS.h"
#include "kernel/Globals.h"
// 16-Bit Code aufrufen, siehe Konstruktor und Aufruf in startup.asm
extern "C" { void bios_call(); }
extern "C" {
void bios_call();
}
// in startup.asm im GDT-Eintrag so festgeschrieben!
#define BIOS16_CODE_MEMORY_START 0x24000
#define BIOS16_CODE_MEMORY_START 0x24000
// Parameter fuer BIOS-Aufrufe (Register)
#define BIOS16_PARAM_BASE 0x26000
#define BIOS16_PARAM_BASE 0x26000
// Zeiger auf Speichbereich fuer Parameter fuer BIOS-Aufruf (siehe BIOS.h)
struct BIOScall_params* BC_params = (struct BIOScall_params*)BIOS16_PARAM_BASE;
/*****************************************************************************
* Methode: BIOS::BIOS *
*---------------------------------------------------------------------------*
@ -34,186 +33,280 @@ struct BIOScall_params* BC_params = (struct BIOScall_params*)BIOS16_PARAM_BASE;
* im 4. GDT-Eintrag (siehe startup.asm). *
*****************************************************************************/
BIOS::BIOS() {
unsigned char *codeAddr = (unsigned char*)BIOS16_CODE_MEMORY_START;
unsigned char* codeAddr = (unsigned char*)BIOS16_CODE_MEMORY_START;
// mov eax, 25000 (Adresse wohin aktuelles esp gesichert wird)
*codeAddr = 0x66; codeAddr++;
*codeAddr = 0xB8; codeAddr++;
*codeAddr = 0x00; codeAddr++;
*codeAddr = 0x50; codeAddr++;
*codeAddr = 0x02; codeAddr++;
*codeAddr = 0x00; codeAddr++;
*codeAddr = 0x66;
codeAddr++;
*codeAddr = 0xB8;
codeAddr++;
*codeAddr = 0x00;
codeAddr++;
*codeAddr = 0x50;
codeAddr++;
*codeAddr = 0x02;
codeAddr++;
*codeAddr = 0x00;
codeAddr++;
// mov [eax], esp (esp abspeichern)
*codeAddr = 0x66; codeAddr++;
*codeAddr = 0x67; codeAddr++;
*codeAddr = 0x89; codeAddr++;
*codeAddr = 0x20; codeAddr++;
*codeAddr = 0x66;
codeAddr++;
*codeAddr = 0x67;
codeAddr++;
*codeAddr = 0x89;
codeAddr++;
*codeAddr = 0x20;
codeAddr++;
// mov eax,cr0 (cr0 auslesen)
*codeAddr = 0x0F; codeAddr++;
*codeAddr = 0x20; codeAddr++;
*codeAddr = 0xC0; codeAddr++;
*codeAddr = 0x0F;
codeAddr++;
*codeAddr = 0x20;
codeAddr++;
*codeAddr = 0xC0;
codeAddr++;
// and eax, 7FFEFFFE (Bitmaske zum Abschlaten des Protected-Mode)
*codeAddr = 0x66; codeAddr++;
*codeAddr = 0x25; codeAddr++;
*codeAddr = 0xFE; codeAddr++;
*codeAddr = 0xFF; codeAddr++;
*codeAddr = 0xFE; codeAddr++;
*codeAddr = 0x7F; codeAddr++;
*codeAddr = 0x66;
codeAddr++;
*codeAddr = 0x25;
codeAddr++;
*codeAddr = 0xFE;
codeAddr++;
*codeAddr = 0xFF;
codeAddr++;
*codeAddr = 0xFE;
codeAddr++;
*codeAddr = 0x7F;
codeAddr++;
// mov cr0, eax (cr0 syetzen um den Protected-Mode auszuschalten)
*codeAddr = 0x0F; codeAddr++;
*codeAddr = 0x22; codeAddr++;
*codeAddr = 0xC0; codeAddr++;
*codeAddr = 0x0F;
codeAddr++;
*codeAddr = 0x22;
codeAddr++;
*codeAddr = 0xC0;
codeAddr++;
// jmp 2400:001B Instruktions-Pipeline leeren und Dekodierungseinheit auf 16-Bit code umschalten
// Wir springen hier zur naechsten Instruktion (*)
// 2400:001B (2400<<4 = 24000 + 1B)
*codeAddr = 0xEA; codeAddr++;
*codeAddr = 0x1B; codeAddr++;
*codeAddr = 0x00; codeAddr++;
*codeAddr = 0x00; codeAddr++;
*codeAddr = 0x24; codeAddr++;
*codeAddr = 0xEA;
codeAddr++;
*codeAddr = 0x1B;
codeAddr++;
*codeAddr = 0x00;
codeAddr++;
*codeAddr = 0x00;
codeAddr++;
*codeAddr = 0x24;
codeAddr++;
// (*) mov dx,2400 (Lade 0x2400 nach dx (fuer Parameter-Zugriff -> BIOS16_PARAM_BAS)
*codeAddr = 0xBA; codeAddr++;
*codeAddr = 0x00; codeAddr++;
*codeAddr = 0x24; codeAddr++;
*codeAddr = 0xBA;
codeAddr++;
*codeAddr = 0x00;
codeAddr++;
*codeAddr = 0x24;
codeAddr++;
// mov ss,dx (Lade Stack-Segment-Register)
*codeAddr = 0x8E; codeAddr++;
*codeAddr = 0xD2; codeAddr++;
// mov gs,dx
*codeAddr = 0x8E; codeAddr++;
*codeAddr = 0xEA; codeAddr++;
*codeAddr = 0x8E;
codeAddr++;
*codeAddr = 0xD2;
codeAddr++;
// mov gs,dx
*codeAddr = 0x8E;
codeAddr++;
*codeAddr = 0xEA;
codeAddr++;
// mov esp,2000 -> BIOS16_PARAM_BASE 0x260000 (= 0x2400:2000)
*codeAddr = 0x66; codeAddr++;
*codeAddr = 0xBC; codeAddr++;
*codeAddr = 0x00; codeAddr++;
*codeAddr = 0x20; codeAddr++;
*codeAddr = 0x00; codeAddr++;
*codeAddr = 0x00; codeAddr++;
*codeAddr = 0x66;
codeAddr++;
*codeAddr = 0xBC;
codeAddr++;
*codeAddr = 0x00;
codeAddr++;
*codeAddr = 0x20;
codeAddr++;
*codeAddr = 0x00;
codeAddr++;
*codeAddr = 0x00;
codeAddr++;
// Register laden (stehen in BIOS16_PARAM_BASE, ab 0x260000)
// (pop erhöht die Adressen)
// pop ds
*codeAddr = 0x1F; codeAddr++;
*codeAddr = 0x1F;
codeAddr++;
// pop es
*codeAddr = 0x07; codeAddr++;
*codeAddr = 0x07;
codeAddr++;
// pop fs
*codeAddr = 0x0f; codeAddr++;
*codeAddr = 0xa1; codeAddr++;
// pop ax
*codeAddr = 0x58; codeAddr++;
*codeAddr = 0x0f;
codeAddr++;
*codeAddr = 0xa1;
codeAddr++;
// pop ax
*codeAddr = 0x58;
codeAddr++;
// popad
*codeAddr = 0x66; codeAddr++;
*codeAddr = 0x61; codeAddr++;
*codeAddr = 0x66;
codeAddr++;
*codeAddr = 0x61;
codeAddr++;
// int(nr)
*codeAddr = 0xCD; codeAddr++; // 'int' Instruktion
*codeAddr = 0x00; codeAddr++; // Nummer (wird direkt von BIOS::Int direkt hier reingeschrieben)
*codeAddr = 0xCD;
codeAddr++; // 'int' Instruktion
*codeAddr = 0x00;
codeAddr++; // Nummer (wird direkt von BIOS::Int direkt hier reingeschrieben)
// Register speichern in BIOS16_PARAM_BASE (ab 0x260000)
// pushad
*codeAddr = 0x66; codeAddr++;
*codeAddr = 0x60; codeAddr++;
*codeAddr = 0x66;
codeAddr++;
*codeAddr = 0x60;
codeAddr++;
// pushf
*codeAddr = 0x9C; codeAddr++;
*codeAddr = 0x9C;
codeAddr++;
// push fs
*codeAddr = 0x0f; codeAddr++;
*codeAddr = 0xa0; codeAddr++;
*codeAddr = 0x0f;
codeAddr++;
*codeAddr = 0xa0;
codeAddr++;
// push es
*codeAddr = 0x06; codeAddr++;
*codeAddr = 0x06;
codeAddr++;
// push ds
*codeAddr = 0x1E; codeAddr++;
*codeAddr = 0x1E;
codeAddr++;
// mov eax,cr0
*codeAddr = 0x0F; codeAddr++;
*codeAddr = 0x20; codeAddr++;
*codeAddr = 0xC0; codeAddr++;
*codeAddr = 0x0F;
codeAddr++;
*codeAddr = 0x20;
codeAddr++;
*codeAddr = 0xC0;
codeAddr++;
// or eax, 00010001 (protected mode without paging)
*codeAddr = 0x66; codeAddr++;
*codeAddr = 0x0D; codeAddr++;
*codeAddr = 0x01; codeAddr++;
*codeAddr = 0x00; codeAddr++;
*codeAddr = 0x01; codeAddr++;
*codeAddr = 0x00; codeAddr++;
*codeAddr = 0x66;
codeAddr++;
*codeAddr = 0x0D;
codeAddr++;
*codeAddr = 0x01;
codeAddr++;
*codeAddr = 0x00;
codeAddr++;
*codeAddr = 0x01;
codeAddr++;
*codeAddr = 0x00;
codeAddr++;
// mov cr0, eax
*codeAddr = 0x0F; codeAddr++;
*codeAddr = 0x22; codeAddr++;
*codeAddr = 0xC0; codeAddr++;
*codeAddr = 0x0F;
codeAddr++;
*codeAddr = 0x22;
codeAddr++;
*codeAddr = 0xC0;
codeAddr++;
// jmp 0018:0049, flush pipeline & switch decoding (active 32 Bit PM)
// 0018:0049
*codeAddr = 0xEA; codeAddr++;
*codeAddr = 0x49; codeAddr++;
*codeAddr = 0x00; codeAddr++;
*codeAddr = 0x18; codeAddr++;
*codeAddr = 0x00; codeAddr++;
// mov dx,0010
*codeAddr = 0xBA; codeAddr++;
*codeAddr = 0x10; codeAddr++;
*codeAddr = 0x00; codeAddr++;
// mov ds,dx
*codeAddr = 0x8E; codeAddr++;
*codeAddr = 0xDA; codeAddr++;
// mov es,dx
*codeAddr = 0x8E; codeAddr++;
*codeAddr = 0xC2; codeAddr++;
// mov es,dx
*codeAddr = 0x8E; codeAddr++;
*codeAddr = 0xE2; codeAddr++;
// mov fs,dx
*codeAddr = 0x8E; codeAddr++;
*codeAddr = 0xEA; codeAddr++;
// mov ss,dx
*codeAddr = 0x8E; codeAddr++;
*codeAddr = 0xD2; codeAddr++;
// mov eax, 25000
*codeAddr = 0x66; codeAddr++;
*codeAddr = 0xB8; codeAddr++;
*codeAddr = 0x00; codeAddr++;
*codeAddr = 0x50; codeAddr++;
*codeAddr = 0x02; codeAddr++;
*codeAddr = 0x00; codeAddr++;
// mov esp, [eax]
*codeAddr = 0x66; codeAddr++;
*codeAddr = 0x67; codeAddr++;
*codeAddr = 0x8B; codeAddr++;
*codeAddr = 0x20; codeAddr++;
// far ret
*codeAddr = 0x66; codeAddr++;
*codeAddr = 0xCB; codeAddr++;
}
*codeAddr = 0xEA;
codeAddr++;
*codeAddr = 0x49;
codeAddr++;
*codeAddr = 0x00;
codeAddr++;
*codeAddr = 0x18;
codeAddr++;
*codeAddr = 0x00;
codeAddr++;
// mov dx,0010
*codeAddr = 0xBA;
codeAddr++;
*codeAddr = 0x10;
codeAddr++;
*codeAddr = 0x00;
codeAddr++;
// mov ds,dx
*codeAddr = 0x8E;
codeAddr++;
*codeAddr = 0xDA;
codeAddr++;
// mov es,dx
*codeAddr = 0x8E;
codeAddr++;
*codeAddr = 0xC2;
codeAddr++;
// mov es,dx
*codeAddr = 0x8E;
codeAddr++;
*codeAddr = 0xE2;
codeAddr++;
// mov fs,dx
*codeAddr = 0x8E;
codeAddr++;
*codeAddr = 0xEA;
codeAddr++;
// mov ss,dx
*codeAddr = 0x8E;
codeAddr++;
*codeAddr = 0xD2;
codeAddr++;
// mov eax, 25000
*codeAddr = 0x66;
codeAddr++;
*codeAddr = 0xB8;
codeAddr++;
*codeAddr = 0x00;
codeAddr++;
*codeAddr = 0x50;
codeAddr++;
*codeAddr = 0x02;
codeAddr++;
*codeAddr = 0x00;
codeAddr++;
// mov esp, [eax]
*codeAddr = 0x66;
codeAddr++;
*codeAddr = 0x67;
codeAddr++;
*codeAddr = 0x8B;
codeAddr++;
*codeAddr = 0x20;
codeAddr++;
// far ret
*codeAddr = 0x66;
codeAddr++;
*codeAddr = 0xCB;
codeAddr++;
}
/*****************************************************************************
* Methode: BIOS::Int *
@ -221,15 +314,12 @@ BIOS::BIOS() {
* Beschreibung: Fuehrt einen BIOS-Aufruf per Software-Interrupt durch. *
*****************************************************************************/
void BIOS::Int(int inter) {
unsigned char *ptr = (unsigned char*)BIOS16_CODE_MEMORY_START;
unsigned char* ptr = (unsigned char*)BIOS16_CODE_MEMORY_START;
// Interrupt-Nummer in 16-Bit Code-Segment schreiben (unschoen, aber ...)
*(ptr+48) = (unsigned char)inter;
cpu.disable_int (); // Interrupts abschalten
bios_call ();
cpu.enable_int ();
*(ptr + 48) = (unsigned char)inter;
cpu.disable_int(); // Interrupts abschalten
bios_call();
cpu.enable_int();
}