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proof of concept interrupt wrapping

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This commit is contained in:
Vladimir 'phcoder' Serbinenko 2009-12-31 13:07:51 +01:00
parent f5a513064c
commit eb3f57d3c4
5 changed files with 176 additions and 78 deletions
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54
disk/i386/pc/biosdisk.c
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@ -19,6 +19,7 @@
#include <grub/machine/biosdisk.h>
#include <grub/machine/memory.h>
#include <grub/machine/kernel.h>
#include <grub/machine/int.h>
#include <grub/disk.h>
#include <grub/dl.h>
#include <grub/mm.h>
@ -28,6 +29,59 @@
#include <grub/term.h>
static int cd_drive = 0;
static int grub_biosdisk_rw_int13_extensions (int ah, int drive, void *dap);
static int grub_biosdisk_get_num_floppies (void)
{
struct grub_cpu_int_registers regs;
int drive;
/* reset the disk system first */
regs.ax = 0;
regs.dx = 0;
regs.flags = GRUB_CPU_INT_FLAGS_DEFAULT;
grub_cpu_interrupt (0x13, &regs);
for (drive = 0; drive < 2; drive++)
{
regs.flags = GRUB_CPU_INT_FLAGS_DEFAULT | GRUB_CPU_INT_FLAGS_CARRY;
regs.dx = drive;
/* call GET DISK TYPE */
regs.ax = 0x1500;
grub_cpu_interrupt (0x13, &regs);
if (regs.flags & GRUB_CPU_INT_FLAGS_CARRY)
break;
/* check if this drive exists */
if (!(regs.ax & 0x300))
break;
}
return drive;
}
/*
* Call IBM/MS INT13 Extensions (int 13 %ah=AH) for DRIVE. DAP
* is passed for disk address packet. If an error occurs, return
* non-zero, otherwise zero.
*/
static int
grub_biosdisk_rw_int13_extensions (int ah, int drive, void *dap)
{
struct grub_cpu_int_registers regs;
regs.ax = ah << 8;
/* compute the address of disk_address_packet */
regs.ds = (((grub_addr_t) dap) & 0xffff0000) >> 4;
regs.si = (((grub_addr_t) dap) & 0xffff);
regs.dx = drive;
regs.flags = GRUB_CPU_INT_FLAGS_DEFAULT;
grub_cpu_interrupt (0x13, &regs);
return regs.ax >> 8;
}
static int
grub_biosdisk_get_drive (const char *name)