Intwrapped biosdisk

This commit is contained in:
Vladimir 'phcoder' Serbinenko 2010-04-04 18:43:26 +02:00
parent 42c4f00016
commit 77356db852
5 changed files with 162 additions and 272 deletions

View file

@ -54,8 +54,7 @@ kernel_img_SOURCES = kern/i386/pc/startup.S \
kern/env.c \
term/i386/pc/console.c term/i386/vga_common.c \
symlist.c
kernel_img_HEADERS += machine/biosdisk.h machine/pxe.h i386/pit.h \
machine/init.h machine/int.h
kernel_img_HEADERS += machine/pxe.h i386/pit.h machine/int.h
kernel_img_CFLAGS = $(COMMON_CFLAGS) $(TARGET_IMG_CFLAGS)
kernel_img_ASFLAGS = $(COMMON_ASFLAGS)
kernel_img_LDFLAGS = $(COMMON_LDFLAGS) $(TARGET_IMG_LDFLAGS)$(GRUB_KERNEL_MACHINE_LINK_ADDR) $(COMMON_CFLAGS)

View file

@ -83,6 +83,166 @@ grub_biosdisk_rw_int13_extensions (int ah, int drive, void *dap)
return (regs.eax >> 8) & 0xff;
}
/*
* Call standard and old INT13 (int 13 %ah=AH) for DRIVE. Read/write
* NSEC sectors from COFF/HOFF/SOFF into SEGMENT. If an error occurs,
* return non-zero, otherwise zero.
*/
static int
grub_biosdisk_rw_standard (int ah, int drive, int coff, int hoff,
int soff, int nsec, int segment)
{
int ret, i;
/* Try 3 times. */
for (i = 0; i < 3; i++)
{
struct grub_bios_int_registers regs;
/* set up CHS information */
/* set %ch to low eight bits of cylinder */
regs.ecx = (coff << 8) & 0xff00;
/* set bits 6-7 of %cl to high two bits of cylinder */
regs.ecx |= (coff >> 2) & 0xc0;
/* set bits 0-5 of %cl to sector */
regs.ecx |= soff & 0x3f;
/* set %dh to head and %dl to drive */
regs.edx = (drive & 0xff) | ((hoff << 8) & 0xff00);
/* set %ah to AH */
regs.eax = (ah << 8) & 0xff00;
/* set %al to NSEC */
regs.eax |= nsec & 0xff;
regs.ebx = 0;
regs.es = segment;
regs.flags = GRUB_CPU_INT_FLAGS_DEFAULT;
grub_bios_interrupt (0x13, &regs);
/* check if successful */
if (!(regs.flags & GRUB_CPU_INT_FLAGS_CARRY))
return 0;
/* save return value */
ret = regs.eax >> 8;
/* if fail, reset the disk system */
regs.eax = 0;
regs.edx = (drive & 0xff);
regs.flags = GRUB_CPU_INT_FLAGS_DEFAULT;
grub_bios_interrupt (0x13, &regs);
}
return ret;
}
/*
* Check if LBA is supported for DRIVE. If it is supported, then return
* the major version of extensions, otherwise zero.
*/
static int
grub_biosdisk_check_int13_extensions (int drive)
{
struct grub_bios_int_registers regs;
regs.edx = drive & 0xff;
regs.eax = 0x4100;
regs.ebx = 0x55aa;
regs.flags = GRUB_CPU_INT_FLAGS_DEFAULT;
grub_bios_interrupt (0x13, &regs);
if (regs.flags & GRUB_CPU_INT_FLAGS_CARRY)
return 0;
if ((regs.ebx & 0xffff) != 0xaa55)
return 0;
/* check if AH=0x42 is supported */
if (!(regs.ecx & 1))
return 0;
return (regs.eax >> 8) & 0xff;
}
/*
* Return the geometry of DRIVE in CYLINDERS, HEADS and SECTORS. If an
* error occurs, then return non-zero, otherwise zero.
*/
static int
grub_biosdisk_get_diskinfo_standard (int drive,
unsigned long *cylinders,
unsigned long *heads,
unsigned long *sectors)
{
struct grub_bios_int_registers regs;
regs.eax = 0x0800;
regs.edx = drive & 0xff;
regs.flags = GRUB_CPU_INT_FLAGS_DEFAULT;
grub_bios_interrupt (0x13, &regs);
/* Check if unsuccessful. Ignore return value if carry isn't set to
workaround some buggy BIOSes. */
if ((regs.flags & GRUB_CPU_INT_FLAGS_CARRY) && ((regs.eax & 0xff00) != 0))
return (regs.eax & 0xff00) >> 8;
/* bogus BIOSes may not return an error number */
/* 0 sectors means no disk */
if (!(regs.ecx & 0x3f))
/* XXX 0x60 is one of the unused error numbers */
return 0x60;
/* the number of heads is counted from zero */
*heads = ((regs.edx >> 8) & 0xff) + 1;
*cylinders = (((regs.ecx >> 8) & 0xff) | ((regs.ecx << 2) & 0x0300)) + 1;
*sectors = regs.ecx & 0x3f;
return 0;
}
static int
grub_biosdisk_get_diskinfo_real (int drive, void *drp, grub_uint16_t ax)
{
struct grub_bios_int_registers regs;
regs.eax = ax;
/* compute the address of drive parameters */
regs.esi = ((grub_addr_t) drp) & 0xf;
regs.ds = ((grub_addr_t) drp) >> 4;
regs.edx = drive & 0xff;
regs.flags = GRUB_CPU_INT_FLAGS_DEFAULT;
grub_bios_interrupt (0x13, &regs);
/* Check if unsuccessful. Ignore return value if carry isn't set to
workaround some buggy BIOSes. */
if ((regs.flags & GRUB_CPU_INT_FLAGS_CARRY) && ((regs.eax & 0xff00) != 0))
return (regs.eax & 0xff00) >> 8;
return 0;
}
/*
* Return the cdrom information of DRIVE in CDRP. If an error occurs,
* then return non-zero, otherwise zero.
*/
static int
grub_biosdisk_get_cdinfo_int13_extensions (int drive, void *cdrp)
{
return grub_biosdisk_get_diskinfo_real (drive, cdrp, 0x4b01);
}
/*
* Return the geometry of DRIVE in a drive parameters, DRP. If an error
* occurs, then return non-zero, otherwise zero.
*/
static int
grub_biosdisk_get_diskinfo_int13_extensions (int drive, void *drp)
{
return grub_biosdisk_get_diskinfo_real (drive, drp, 0x4800);
}
static int
grub_biosdisk_get_drive (const char *name)
{

View file

@ -106,18 +106,6 @@ struct grub_biosdisk_dap
grub_uint64_t block;
} __attribute__ ((packed));
int EXPORT_FUNC(grub_biosdisk_rw_standard) (int ah, int drive, int coff, int hoff,
int soff, int nsec, int segment);
int EXPORT_FUNC(grub_biosdisk_check_int13_extensions) (int drive);
int EXPORT_FUNC(grub_biosdisk_get_diskinfo_int13_extensions) (int drive,
void *drp);
int EXPORT_FUNC(grub_biosdisk_get_cdinfo_int13_extensions) (int drive,
void *cdrp);
int EXPORT_FUNC(grub_biosdisk_get_diskinfo_standard) (int drive,
unsigned long *cylinders,
unsigned long *heads,
unsigned long *sectors);
void grub_biosdisk_init (void);
void grub_biosdisk_fini (void);

View file

@ -33,7 +33,7 @@ grub_uint32_t grub_get_eisa_mmap (void);
/* Get a memory map entry. Return next continuation value. Zero means
the end. */
grub_uint32_t EXPORT_FUNC(grub_get_mmap_entry) (struct grub_machine_mmap_entry *entry,
grub_uint32_t grub_get_mmap_entry (struct grub_machine_mmap_entry *entry,
grub_uint32_t cont);
/* Turn on/off Gate A20. */

View file

@ -505,263 +505,6 @@ FUNCTION(grub_chainloader_real_boot)
#include "../loader.S"
/*
* int grub_biosdisk_rw_standard (int ah, int drive, int coff, int hoff,
* int soff, int nsec, int segment)
*
* Call standard and old INT13 (int 13 %ah=AH) for DRIVE. Read/write
* NSEC sectors from COFF/HOFF/SOFF into SEGMENT. If an error occurs,
* return non-zero, otherwise zero.
*/
FUNCTION(grub_biosdisk_rw_standard)
pushl %ebp
movl %esp, %ebp
pushl %ebx
pushl %edi
pushl %esi
/* set up CHS information */
/* set %ch to low eight bits of cylinder */
xchgb %cl, %ch
/* set bits 6-7 of %cl to high two bits of cylinder */
shlb $6, %cl
/* set bits 0-5 of %cl to sector */
addb 0xc(%ebp), %cl
/* set %dh to head */
movb 0x8(%ebp), %dh
/* set %ah to AH */
movb %al, %ah
/* set %al to NSEC */
movb 0x10(%ebp), %al
/* save %ax in %di */
movw %ax, %di
/* save SEGMENT in %bx */
movw 0x14(%ebp), %bx
/* enter real mode */
call prot_to_real
.code16
movw %bx, %es
xorw %bx, %bx
movw $3, %si /* attempt at least three times */
1:
movw %di, %ax
int $0x13 /* do the operation */
jnc 2f /* check if successful */
movb %ah, %bl /* save return value */
/* if fail, reset the disk system */
xorw %ax, %ax
int $0x13
decw %si
cmpw $0, %si
je 2f
xorb %bl, %bl
jmp 1b /* retry */
2:
/* back to protected mode */
DATA32 call real_to_prot
.code32
movb %bl, %al /* return value in %eax */
popl %esi
popl %edi
popl %ebx
popl %ebp
ret $(4 * 4)
/*
* int grub_biosdisk_check_int13_extensions (int drive)
*
* Check if LBA is supported for DRIVE. If it is supported, then return
* the major version of extensions, otherwise zero.
*/
FUNCTION(grub_biosdisk_check_int13_extensions)
pushl %ebp
pushl %ebx
/* drive */
movb %al, %dl
/* enter real mode */
call prot_to_real
.code16
movb $0x41, %ah
movw $0x55aa, %bx
int $0x13 /* do the operation */
/* check the result */
jc 1f
cmpw $0xaa55, %bx
jne 1f
movb %ah, %bl /* save the major version into %bl */
/* check if AH=0x42 is supported */
andw $1, %cx
jnz 2f
1:
xorb %bl, %bl
2:
/* back to protected mode */
DATA32 call real_to_prot
.code32
movb %bl, %al /* return value in %eax */
popl %ebx
popl %ebp
ret
/*
* int grub_biosdisk_get_cdinfo_int13_extensions (int drive, void *cdrp)
*
* Return the cdrom information of DRIVE in CDRP. If an error occurs,
* then return non-zero, otherwise zero.
*/
FUNCTION(grub_biosdisk_get_cdinfo_int13_extensions)
movw $0x4B01, %cx
jmp 1f
/*
* int grub_biosdisk_get_diskinfo_int13_extensions (int drive, void *drp)
*
* Return the geometry of DRIVE in a drive parameters, DRP. If an error
* occurs, then return non-zero, otherwise zero.
*/
FUNCTION(grub_biosdisk_get_diskinfo_int13_extensions)
movb $0x48, %ch
1:
pushl %ebp
pushl %ebx
pushl %esi
/* compute the address of drive parameters */
movw %dx, %si
andl $0xf, %esi
shrl $4, %edx
movw %dx, %bx /* save the segment into %bx */
/* drive */
movb %al, %dl
/* enter real mode */
call prot_to_real
.code16
movw %cx, %ax
movw %bx, %ds
int $0x13 /* do the operation */
jc noclean
/* Clean return value if carry isn't set to workaround
some buggy BIOSes. */
xor %ax, %ax
noclean:
movb %ah, %bl /* save return value in %bl */
/* back to protected mode */
DATA32 call real_to_prot
.code32
movb %bl, %al /* return value in %eax */
popl %esi
popl %ebx
popl %ebp
ret
/*
* int grub_biosdisk_get_diskinfo_standard (int drive,
* unsigned long *cylinders,
* unsigned long *heads,
* unsigned long *sectors)
*
* Return the geometry of DRIVE in CYLINDERS, HEADS and SECTORS. If an
* error occurs, then return non-zero, otherwise zero.
*/
FUNCTION(grub_biosdisk_get_diskinfo_standard)
pushl %ebp
pushl %ebx
pushl %edi
/* push CYLINDERS */
pushl %edx
/* push HEADS */
pushl %ecx
/* SECTORS is on the stack */
/* drive */
movb %al, %dl
/* enter real mode */
call prot_to_real
.code16
movb $0x8, %ah
int $0x13 /* do the operation */
jc noclean2
/* Clean return value if carry isn't set to workaround
some buggy BIOSes. */
xor %ax, %ax
noclean2:
/* check if successful */
testb %ah, %ah
jnz 1f
/* bogus BIOSes may not return an error number */
testb $0x3f, %cl /* 0 sectors means no disk */
jnz 1f /* if non-zero, then succeed */
/* XXX 0x60 is one of the unused error numbers */
movb $0x60, %ah
1:
movb %ah, %bl /* save return value in %bl */
/* back to protected mode */
DATA32 call real_to_prot
.code32
/* pop HEADS */
popl %edi
movb %dh, %al
incl %eax /* the number of heads is counted from zero */
movl %eax, (%edi)
/* pop CYLINDERS */
popl %edi
movb %ch, %al
movb %cl, %ah
shrb $6, %ah /* the number of cylinders is counted from zero */
incl %eax
movl %eax, (%edi)
/* SECTORS */
movl 0x10(%esp), %edi
andb $0x3f, %cl
movzbl %cl, %eax
movl %eax, (%edi)
xorl %eax, %eax
movb %bl, %al /* return value in %eax */
popl %edi
popl %ebx
popl %ebp
ret $4
/*
*
* grub_get_memsize(i) : return the memory size in KB. i == 0 for conventional