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2022-07-24 21:12:31 +02:00

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/*****************************************************************************
* *
* V E S A *
* *
*---------------------------------------------------------------------------*
* Beschreibung: VESA-Treiber ueber 16-Bit BIOS. *
* *
* Autor: Michael Schoettner, HHU, 18.3.2017 *
*****************************************************************************/
#include "devices/VESA.h"
#include "kernel/BIOS.h"
#include "kernel/Globals.h"
// Informationen ueber einen VESA-Grafikmodus
// (siehe http://wiki.osdev.org/VESA_Video_Modes)
struct VbeModeInfoBlock {
unsigned short attributes;
unsigned char winA, winB;
unsigned short granularity;
unsigned short winsize;
unsigned short segmentA, segmentB;
unsigned short realFctPtr[2];
unsigned short pitch; // Bytes pro Scanline
unsigned short Xres, Yres;
unsigned char Wchar, Ychar, planes, bpp, banks;
unsigned char memory_model, bank_size, image_pages;
unsigned char reserved0;
unsigned char red_mask, red_position;
unsigned char green_mask, green_position;
unsigned char blue_mask, blue_position;
unsigned char rsv_mask, rsv_position;
unsigned char directcolor_attributes;
unsigned int physbase; // Adresse des Linear-Framebuffers
unsigned int OffScreenMemOffset;
unsigned short OffScreenMemSize;
} __attribute__((packed));
// Informationen ueber die Grafikkarte
// (siehe http://wiki.osdev.org/VESA_Video_Modes)
struct VbeInfoBlock {
char VbeSignature[4]; // == "VESA"
unsigned short VbeVersion; // == 0x0300 for VBE 3.0
unsigned short OemStringPtr[2]; // isa vbeFarPtr
unsigned char Capabilities[4];
unsigned short VideoModePtr[2]; // isa vbeFarPtr
unsigned short TotalMemory; // as # of 64KB blocks
} __attribute__((packed));
/*****************************************************************************
* Methode: VESA::initTextMode *
*---------------------------------------------------------------------------*
* Beschreibung: Schalter in den Text-Modus 80x25 Zeichen. *
*****************************************************************************/
void VESA::initTextMode() {
BC_params->AX = 0x4f02; // SVFA BIOS, init mode
BC_params->BX = 0x4003; // 80x25
BIOS::Int(0x10);
}
/*****************************************************************************
* Methode: VESA::initGraphicMode *
*---------------------------------------------------------------------------*
* Parameter: Nummer des Grafikmodus (siehe VESA.h) *
* *
* Beschreibung: Bestimmten Grafikmodus einschalten. Dies wird durch *
* einen Aufruf des BIOS gemacht. *
*****************************************************************************/
bool VESA::initGraphicMode(unsigned short mode) {
// Alle Grafikmodi abfragen
BC_params->AX = 0x4F00;
BC_params->ES = RETURN_MEM >> 4;
BC_params->DI = RETURN_MEM & 0xF;
BIOS::Int(0x10);
VbeInfoBlock* ib = reinterpret_cast<VbeInfoBlock*>(RETURN_MEM);
// Signaturen pruefen
if (BC_params->AX != 0x004F) {
log.error() << "VESA wird nicht unterstuetzt." << endl;
return false;
}
if (ib->VbeSignature[0] != 'V' || ib->VbeSignature[1] != 'E' ||
ib->VbeSignature[2] != 'S' || ib->VbeSignature[3] != 'A') {
log.error() << "VESA wird nicht unterstuetzt." << endl;
return false;
}
// kout << "TotalVideoMemory: " << ((ib->TotalMemory*65536) / (1024*1024)) << " MB" << endl;
// Gewuenschten Grafikmodus aus Antwort suchen
unsigned short* modePtr = reinterpret_cast<unsigned short*>((ib->VideoModePtr[1] << 4) + ib->VideoModePtr[0]);
for (int i = 0; modePtr[i] != 0xFFFF; ++i) {
// Gewuenschter Grafikmodus gefunden?
if (modePtr[i] == mode) {
VbeModeInfoBlock* minf = reinterpret_cast<VbeModeInfoBlock*>(RETURN_MEM);
// Weitere Infos ueber diesen Grafikmodus abfragen
BC_params->AX = 0x4F01;
BC_params->CX = mode;
BC_params->ES = RETURN_MEM >> 4;
BC_params->DI = RETURN_MEM & 0xF;
BIOS::Int(0x10);
// Text-Modi 0-3 haben keinen LFB
if (mode > 3 && (minf->attributes & 0x90) == 0) {
log.error() << "Grafikmodus bietet keinen linearen Framebuffer." << endl;
return false;
}
mode_nr = mode;
xres = minf->Xres;
yres = minf->Yres;
bpp = static_cast<int>(minf->bpp);
lfb = minf->physbase;
hfb = reinterpret_cast<unsigned int>(new char[xres * yres * bpp / 8]);
// Grafikmodus einschalten
BC_params->AX = 0x4f02; // SVFA BIOS, init mode
BC_params->BX = mode;
BIOS::Int(0x10);
return true;
}
}
log.error() << "Grafikmodus nicht gefunden." << endl;
return false;
}