[block] Centralise "san-drive" setting

The concept of the SAN drive number is meaningful only in a BIOS
environment, where it represents the INT13 drive number (0x80 for the
first hard disk).  We retain this concept in a UEFI environment to
allow for a simple way for iPXE commands to refer to SAN drives.

Centralise the concept of the default drive number, since it is shared
between all supported environments.

Signed-off-by: Michael Brown <mcb30@ipxe.org>

src/arch/x86/interface/pcbios/int13.c

 #include <ipxe/pci.h>
 #include <ipxe/iso9660.h>
 #include <ipxe/eltorito.h>
-#include <ipxe/dhcp.h>
-#include <ipxe/settings.h>
 #include <realmode.h>
 #include <bios.h>
 #include <biosint.h>
 	return 0;
 }
 
-/** The "san-drive" setting */
-const struct setting san_drive_setting __setting ( SETTING_SANBOOT_EXTRA,
-						   san-drive ) = {
-	.name = "san-drive",
-	.description = "SAN drive number",
-	.tag = DHCP_EB_SAN_DRIVE,
-	.type = &setting_type_uint8,
-};
-
-/**
- * Get default SAN drive number
- *
- * @ret drive		Default drive number
- */
-static unsigned int int13_default_drive ( void ) {
-	unsigned long drive;
-
-	/* Use "san-drive" setting, if specified */
-	if ( fetch_uint_setting ( NULL, &san_drive_setting, &drive ) >= 0 )
-		return drive;
-
-	/* Otherwise, default to booting from first hard disk */
-	return 0x80;
-}
-
-PROVIDE_SANBOOT ( pcbios, san_default_drive, int13_default_drive );
 PROVIDE_SANBOOT ( pcbios, san_hook, int13_hook );
 PROVIDE_SANBOOT ( pcbios, san_unhook, int13_unhook );
 PROVIDE_SANBOOT ( pcbios, san_boot, int13_boot );

src/core/null_sanboot.c

 	return -EOPNOTSUPP;
 }
 
-PROVIDE_SANBOOT_INLINE ( null, san_default_drive );
 PROVIDE_SANBOOT ( null, san_hook, null_san_hook );
 PROVIDE_SANBOOT ( null, san_unhook, null_san_unhook );
 PROVIDE_SANBOOT ( null, san_boot, null_san_boot );

src/core/sanboot.c

 #include <ipxe/timer.h>
 #include <ipxe/process.h>
 #include <ipxe/iso9660.h>
+#include <ipxe/dhcp.h>
+#include <ipxe/settings.h>
 #include <ipxe/sanboot.h>
 
+/**
+ * Default SAN drive number
+ *
+ * The drive number is a meaningful concept only in a BIOS
+ * environment, where it represents the INT13 drive number (0x80 for
+ * the first hard disk).  We retain it in other environments to allow
+ * for a simple way for iPXE commands to refer to SAN drives.
+ */
+#define SAN_DEFAULT_DRIVE 0x80
+
 /**
  * Timeout for block device commands (in ticks)
  *
 
 	/* Add to list of SAN devices */
 	list_add_tail ( &sandev->list, &san_devices );
+	DBGC ( sandev, "SAN %#02x registered\n", sandev->drive );
 
 	return 0;
 }
 
 	/* Remove from list of SAN devices */
 	list_del ( &sandev->list );
+	DBGC ( sandev, "SAN %#02x unregistered\n", sandev->drive );
+}
+
+/** The "san-drive" setting */
+const struct setting san_drive_setting __setting ( SETTING_SANBOOT_EXTRA,
+						   san-drive ) = {
+	.name = "san-drive",
+	.description = "SAN drive number",
+	.tag = DHCP_EB_SAN_DRIVE,
+	.type = &setting_type_uint8,
+};
+
+/**
+ * Get default SAN drive number
+ *
+ * @ret drive		Default drive number
+ */
+unsigned int san_default_drive ( void ) {
+	unsigned long drive;
+
+	/* Use "san-drive" setting, if specified */
+	if ( fetch_uint_setting ( NULL, &san_drive_setting, &drive ) >= 0 )
+		return drive;
+
+	/* Otherwise, default to booting from first hard disk */
+	return SAN_DEFAULT_DRIVE;
 }

src/include/ipxe/efi/efi_block.h

 #define SANBOOT_PREFIX_efi __efi_
 #endif
 
-static inline __always_inline unsigned int
-SANBOOT_INLINE ( efi, san_default_drive ) ( void ) {
-	/* Drive numbers don't exist as a concept under EFI.  We
-	 * arbitarily choose to use drive 0x80 to minimise differences
-	 * with a standard BIOS.
-	 */
-	return 0x80;
-}
-
 #endif /* _IPXE_EFI_BLOCK_H */

src/include/ipxe/null_sanboot.h

 #define SANBOOT_PREFIX_null __null_
 #endif
 
-static inline __always_inline unsigned int
-SANBOOT_INLINE ( null, san_default_drive ) ( void ) {
-	return 0;
-}
-
 #endif /* _IPXE_NULL_SANBOOT_H */

src/include/ipxe/sanboot.h

 /* Include all architecture-dependent sanboot API headers */
 #include <bits/sanboot.h>
 
-/**
- * Get default SAN drive number
- *
- * @ret drive		Default drive number
- */
-unsigned int san_default_drive ( void );
-
 /**
  * Hook SAN device
  *
 extern struct san_device * alloc_sandev ( struct uri *uri, size_t priv_size );
 extern int register_sandev ( struct san_device *sandev );
 extern void unregister_sandev ( struct san_device *sandev );
+extern unsigned int san_default_drive ( void );
 
 #endif /* _IPXE_SANBOOT_H */

src/interface/efi/efi_block.c

 	return rc;
 }
 
-PROVIDE_SANBOOT_INLINE ( efi, san_default_drive );
 PROVIDE_SANBOOT ( efi, san_hook, efi_block_hook );
 PROVIDE_SANBOOT ( efi, san_unhook, efi_block_unhook );
 PROVIDE_SANBOOT ( efi, san_describe, efi_block_describe );