* conf/i386-pc.rmk (pkglib_IMAGES): Add cdboot.img.
(cdboot_img_SOURCES): New variable.
(cdboot_img_ASFLAGS): New variable.
(cdboot_img_LDFLAGS): New variable.
* boot/i386/pc/cdboot.S: New file.
* disk/i386/pc/biosdisk.c (cd_start): New variable.
(cd_count): Likewise.
(grub_biosdisk_get_drive): Add support for cd device.
(grub_biosdisk_call_hook): Likewise.
(grub_biosdisk_iterate): Likewise.
(grub_biosdisk_open): Likewise.
(GRUB_BIOSDISK_CDROM_RETRY_COUNT): New macro.
(grub_biosdisk_rw): Support reading from cd device.
(GRUB_MOD_INIT): Iterate cd devices.
* include/grub/i386/pc/biosdisk.h (GRUB_BIOSDISK_FLAG_CDROM): New macro.
(GRUB_BIOSDISK_MACHINE_CDROM_START): Likewise.
(GRUB_BIOSDISK_MACHINE_CDROM_END): Likewise.
* kern/i386/pc/init.c (make_install_device): Check for cd device.
