* include/grub/arc/arc.h (grub_arc_iterate_devs_hook_t): New type.
(grub_arc_iterate_devs): Add hook_data argument.
* include/grub/ata.h (grub_ata_dev_iterate_hook_t): New type.
(struct grub_ata_dev.iterate): Add hook_data argument.
* include/grub/device.h (grub_device_iterate_hook_t): New type.
(grub_device_iterate): Add hook_data argument.
* include/grub/disk.h (grub_disk_dev_iterate_hook_t): New type.
(struct grub_disk_dev.iterate): Add hook_data argument.
(grub_disk_dev_iterate): Likewise.
* include/grub/gpt_partition.h (grub_gpt_partition_map_iterate):
Likewise.
* include/grub/msdos_partition.h (grub_partition_msdos_iterate):
Likewise.
* include/grub/partition.h (grub_partition_iterate_hook_t): New
type.
(struct grub_partition_map.iterate): Add hook_data argument.
(grub_partition_iterate): Likewise.
* include/grub/scsi.h (grub_scsi_dev_iterate_hook_t): New type.
(struct grub_scsi_dev.iterate): Add hook_data argument.

Update all callers.

	* grub-core/disk/ata.c (grub_ata_readwrite): Limit to ata->maxbuffer.
	* grub-core/disk/pata.c (grub_pata_open): Set ata->maxbuffer.
	* grub-core/disk/ahci.c (grub_ahci_open): Likewise.

	* include/grub/ata.h (grub_ata): New member log_sector_size.
	* grub-core/disk/ata.c (grub_ata_dumpinfo): Show sector size.
	(grub_ata_identify): Read sector size.
	(grub_ata_readwrite): Use log_sector_size rather than hardcoded value.

	to spin up.

	* grub-core/disk/ata.c (grub_atapi_identify): Use GRUB_ATA_TOUT_DEV_INIT
	if dev->present is 1. Reset dev->present on failure.
	(grub_ata_device_initialize): Set dev->present to 1.
	* include/grub/ata.h (GRUB_ATA_TOUT_DEV_INIT): New value.
	(grub_ata_device): New member 'present'.

	* commands/hdparm.c: New file.  Provides `hdparm' command
	which sends ATA commands via grub_disk_ata_pass_through ().

	* conf/i386-pc.rmk: Add ata_pthru.mod and hdparm.mod.

	* disk/ata.c: Include <grub/ata.h>.  Move <grub/misc.h>
	and <grub/cpu/io.h> to include/grub/ata.h.
	(enum grub_ata_addressing_t): Move to include/grub/ata.h.
	(GRUB_CDROM_SECTOR_SIZE): Remove.
	(GRUB_ATA_*): Move to include/grub/ata.h.
	(GRUB_ATAPI_*): Likewise.
	(enum grub_ata_commands): Likewise.
	(enum grub_ata_timeout_milliseconds): Likewise.
	(struct grub_ata_device): Likewise.
	(grub_ata_regset): Likewise.
	(grub_ata_regget): Likewise.
	(grub_ata_regset2): Likewise.
	(grub_ata_regget2): Likewise.
	(grub_ata_check_ready): Likewise.
	(grub_ata_wait_not_busy): Remove static, exported in
	include/grub/ata.h.
	(grub_ata_wait_drq): Likewise.
	(grub_ata_pio_read): Likewise.

	* disk/ata_pthru.c: New file.  Provides grub_ata_pass_through ()
	function for hdparm.mod.

	* include/grub/ata.h: New file, contains declarations from
	disk/ata.c.
	(enum grub_ata_commands): Add new commands for commands/hdparm.c.

	* include/grub/disk.h (grub_disk_ata_pass_through_parms): New struct.
	(grub_disk_ata_pass_through): New exported variable.

	* kern/disk.c (grub_disk_ata_pass_through): New variable.