Johan Rydberg wrote:
Johan Rydberg <[EMAIL PROTECTED]> writes:
> This code can be shorter; you only have to compare the lengths. If
> they match, you can do a memcmp on the whole device path.
It could look something like this;
/* Returns zero if device path SUBPATH is a subpath of device path
PATH. */
static int
compare_subpath (const grub_efi_device_path_t *subpath,
const grub_efi_device_path_t *path)
{
if (! subpath || ! path)
return 1;
while (1)
{
int len, ret;
if (GRUB_EFI_END_ENTIRE_DEVICE_PATH (subpath))
return 0;
else if (GRUB_EFI_END_ENTIRE_DEVICE_PATH (path))
return 1;
if (GRUB_EFI_DEVICE_PATH_LENGTH (subpath)
!= GRUB_EFI_DEVICE_PATH_LENGTH (path))
return ((int) GRUB_EFI_DEVICE_PATH_LENGTH (subpath)
- (int) GRUB_EFI_DEVICE_PATH_LENGTH (path));
len = GRUB_EFI_DEVICE_PATH_LENGTH (path);
ret = grub_memcmp (subpath, path, len);
if (ret)
return ret;
path = (grub_efi_device_path_t *) ((char *) path + len);
subpath = (grub_efi_device_path_t *) ((char *) subpath + len);
}
}
I guess that should work at least, it is not tested.
I tested on my EFI IA32 bios, it works for me, your method is better
than me, I incorporated your function in my second patch.
thanks
bibo,mao
In gnufi I have a device_path_iterate function that could be used for
these kind of things. Maybe we should bring it in to GRUB2.
/* Iterate nodes of the device path. *PATHP should be set to point to
the path that is to be iterated. NULL will be returned when the
end of the path has been reached. */
efi_device_path_t *
efi_device_path_iterate (efi_device_path_t **pathp)
{
efi_device_path_t *p = *pathp;
if (EFI_END_ENTIRE_DEVICE_PATH (p))
return NULL;
else
{
efi_uint_t len = EFI_DEVICE_PATH_LENGTH (p);
*pathp = (efi_device_path_t *) (((char *) p) + len);
return p;
}
}
~j
--- grub2.org/disk/efi/efidisk.c 2006-10-25 12:47:28.000000000 +0800
+++ grub2/disk/efi/efidisk.c 2006-10-25 12:50:19.000000000 +0800
@@ -87,6 +87,39 @@ find_last_device_path (const grub_efi_de
return p;
}
+/* Returns zero if device path SUBPATH is a subpath of device path
+ PATH. */
+static int
+compare_subpath (const grub_efi_device_path_t *subpath,
+ const grub_efi_device_path_t *path)
+{
+ if (! subpath || ! path)
+ return 1;
+
+ while (1)
+ {
+ int len, ret;
+
+ if (GRUB_EFI_END_ENTIRE_DEVICE_PATH (subpath))
+ return 0;
+ else if (GRUB_EFI_END_ENTIRE_DEVICE_PATH (path))
+ return 1;
+
+ if (GRUB_EFI_DEVICE_PATH_LENGTH (subpath)
+ != GRUB_EFI_DEVICE_PATH_LENGTH (path))
+ return ((int) GRUB_EFI_DEVICE_PATH_LENGTH (subpath)
+ - (int) GRUB_EFI_DEVICE_PATH_LENGTH (path));
+
+ len = GRUB_EFI_DEVICE_PATH_LENGTH (path);
+ ret = grub_memcmp (subpath, path, len);
+ if (ret)
+ return ret;
+
+ path = (grub_efi_device_path_t *) ((char *) path + len);
+ subpath = (grub_efi_device_path_t *) ((char *) subpath + len);
+ }
+}
+
/* Compare device paths. */
static int
compare_device_paths (const grub_efi_device_path_t *dp1,
@@ -197,44 +230,6 @@ make_devices (void)
return devices;
}
-/* Find the parent device. */
-static struct grub_efidisk_data *
-find_parent_device (struct grub_efidisk_data *devices,
- struct grub_efidisk_data *d)
-{
- grub_efi_device_path_t *dp, *ldp;
- struct grub_efidisk_data *parent;
-
- dp = duplicate_device_path (d->device_path);
- if (! dp)
- return 0;
-
- ldp = find_last_device_path (dp);
- ldp->type = GRUB_EFI_END_DEVICE_PATH_TYPE;
- ldp->subtype = GRUB_EFI_END_ENTIRE_DEVICE_PATH_SUBTYPE;
- ldp->length[0] = sizeof (*ldp);
- ldp->length[1] = 0;
-
- for (parent = devices; parent; parent = parent->next)
- {
- /* Ignore itself. */
- if (parent == d)
- continue;
-
- if (compare_device_paths (parent->device_path, dp) == 0)
- {
- /* Found. */
- if (! parent->last_device_path)
- parent = 0;
-
- break;
- }
- }
-
- grub_free (dp);
- return parent;
-}
-
static int
iterate_child_devices (struct grub_efidisk_data *devices,
struct grub_efidisk_data *d,
@@ -305,63 +300,6 @@ static void
name_devices (struct grub_efidisk_data *devices)
{
struct grub_efidisk_data *d;
-
- /* First, identify devices by media device paths. */
- for (d = devices; d; d = d->next)
- {
- grub_efi_device_path_t *dp;
-
- dp = d->last_device_path;
- if (! dp)
- continue;
-
- if (GRUB_EFI_DEVICE_PATH_TYPE (dp) == GRUB_EFI_MEDIA_DEVICE_PATH_TYPE)
- {
- int is_hard_drive = 0;
-
- switch (GRUB_EFI_DEVICE_PATH_SUBTYPE (dp))
- {
- case GRUB_EFI_HARD_DRIVE_DEVICE_PATH_SUBTYPE:
- is_hard_drive = 1;
- /* Fall through by intention. */
- case GRUB_EFI_CDROM_DEVICE_PATH_SUBTYPE:
- {
- struct grub_efidisk_data *parent;
-
- parent = find_parent_device (devices, d);
- if (parent)
- {
- if (is_hard_drive)
- {
-#if 0
- grub_printf ("adding a hard drive by a partition: ");
- grub_print_device_path (parent->device_path);
-#endif
- add_device (&hd_devices, parent);
- }
- else
- {
-#if 0
- grub_printf ("adding a cdrom by a partition: ");
- grub_print_device_path (parent->device_path);
-#endif
- add_device (&cd_devices, parent);
- }
-
- /* Mark the parent as used. */
- parent->last_device_path = 0;
- }
- }
- /* Mark itself as used. */
- d->last_device_path = 0;
- break;
-
- default:
- /* For now, ignore the others. */
- break;
- }
- }
- }
/* Let's see what can be added more. */
for (d = devices; d; d = d->next)
@@ -374,34 +312,22 @@ name_devices (struct grub_efidisk_data *
continue;
m = d->block_io->media;
- if (m->logical_partition)
- {
- /* Only one partition in a non-media device. Assume that this
- is a floppy drive. */
-#if 0
- grub_printf ("adding a floppy by guessing: ");
- grub_print_device_path (d->device_path);
-#endif
- add_device (&fd_devices, d);
- }
- else if (m->read_only && m->block_size > GRUB_DISK_SECTOR_SIZE)
+ if (GRUB_EFI_DEVICE_PATH_TYPE(dp) == GRUB_EFI_MESSAGING_DEVICE_PATH_TYPE)
{
- /* This check is too heuristic, but assume that this is a
- CDROM drive. */
-#if 0
- grub_printf ("adding a cdrom by guessing: ");
- grub_print_device_path (d->device_path);
-#endif
- add_device (&cd_devices, d);
+ if (m->read_only && m->block_size > GRUB_DISK_SECTOR_SIZE)
+ {
+ grub_printf("adding a cd by guessing\n");
+ add_device (&cd_devices, d);
+ } else
+ {
+ grub_printf("adding a hd by guessing\n");
+ add_device (&hd_devices, d);
+ }
}
- else
+ if (GRUB_EFI_DEVICE_PATH_TYPE(dp) == GRUB_EFI_ACPI_DEVICE_PATH_TYPE)
{
- /* The default is a hard drive. */
-#if 0
- grub_printf ("adding a hard drive by guessing: ");
- grub_print_device_path (d->device_path);
-#endif
- add_device (&hd_devices, d);
+ grub_printf ("adding a floppy by guessing\n");
+ add_device (&fd_devices, d);
}
}
}
@@ -734,7 +660,6 @@ grub_efidisk_get_device_name (grub_efi_h
grub_disk_t parent = 0;
char *partition_name = 0;
char *device_name;
- grub_efi_device_path_t *dup_dp, *dup_ldp;
grub_efi_hard_drive_device_path_t hd;
auto int find_parent_disk (const char *name);
auto int find_partition (grub_disk_t disk, const grub_partition_t part);
@@ -753,7 +678,7 @@ grub_efidisk_get_device_name (grub_efi_h
struct grub_efidisk_data *d;
d = disk->data;
- if (compare_device_paths (d->device_path, dup_dp) == 0)
+ if (compare_subpath (d->device_path, dp) == 0)
{
parent = disk;
return 1;
@@ -778,20 +703,7 @@ grub_efidisk_get_device_name (grub_efi_h
return 0;
}
- /* It is necessary to duplicate the device path so that GRUB
- can overwrite it. */
- dup_dp = duplicate_device_path (dp);
- if (! dup_dp)
- return 0;
-
- dup_ldp = find_last_device_path (dup_dp);
- dup_ldp->type = GRUB_EFI_END_DEVICE_PATH_TYPE;
- dup_ldp->subtype = GRUB_EFI_END_ENTIRE_DEVICE_PATH_SUBTYPE;
- dup_ldp->length[0] = sizeof (*dup_ldp);
- dup_ldp->length[1] = 0;
-
grub_efidisk_iterate (find_parent_disk);
- grub_free (dup_dp);
if (! parent)
return 0;
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