Subversion Repositories eco32

/*

 * boot.c -- bootstrap from disk

 */

#include "common.h"

#include "stdarg.h"

#include "romlib.h"

#include "boot.h"

#include "cpu.h"

#include "mmu.h"

#include "start.h"

void boot(int dskno) {

  Word capacity;

  Byte sig1, sig2;

  capacity = dskcap(dskno);

  if (capacity == 0) {

    printf("Disk not found!\n");

    return;

  }

  printf("Disk with 0x%08X sectors found, booting...\n", capacity);

  if (dskio(dskno, 'r', 0, PHYS_BOOT, 1) != 0) {

    printf("Disk error!\n");

    return;

  }

  sig1 = mmuReadByte(VIRT_BOOT + 512 - 2);

  sig2 = mmuReadByte(VIRT_BOOT + 512 - 1);

  if (sig1 != 0x55 || sig2 != 0xAA) {

    printf("MBR signature missing!\n");

    return;

  }

  /*

   * Boot convention:

   *   $16  disk number of boot disk

   *   $17  start sector number of disk or partition to boot

   *   $18  total number of sectors of disk or partition to boot

   */

  cpuSetReg(16, dskno);

  cpuSetReg(17, 0);

  cpuSetReg(18, capacity);

  cpuSetPC(VIRT_BOOT);

  cpuRun();

}