[Settings] Convert code in src/usr to use settings API.

src/core/settings.c

 		return;
 
 	/* Read priority, if present */
-	priority = 0;
-	fetch_int_setting ( settings, DHCP_EB_PRIORITY, &priority );
+	priority = fetch_intz_setting ( settings, DHCP_EB_PRIORITY );
 
 	/* Remove from siblings list */
 	list_del ( &settings->siblings );
 
 	/* Reinsert after any existing blocks which have a higher priority */
 	list_for_each_entry ( tmp, &parent->children, siblings ) {
-		tmp_priority = 0;
-		fetch_int_setting ( tmp, DHCP_EB_PRIORITY, &tmp_priority );
+		tmp_priority = fetch_intz_setting ( tmp, DHCP_EB_PRIORITY );
 		if ( priority > tmp_priority )
 			break;
 	}
 	return len;
 }
 
+/**
+ * Fetch value of signed integer setting, or zero
+ *
+ * @v settings		Settings block, or NULL to search all blocks
+ * @v tag		Setting tag number
+ * @ret value		Setting value, or zero
+ */
+long fetch_intz_setting ( struct settings *settings, unsigned int tag ) {
+	long value = 0;
+
+	fetch_int_setting ( settings, tag, &value );
+	return value;
+}
+
+/**
+ * Fetch value of unsigned integer setting, or zero
+ *
+ * @v settings		Settings block, or NULL to search all blocks
+ * @v tag		Setting tag number
+ * @ret value		Setting value, or zero
+ */
+unsigned long fetch_uintz_setting ( struct settings *settings,
+				    unsigned int tag ) {
+	unsigned long value = 0;
+
+	fetch_uint_setting ( settings, tag, &value );
+	return value;
+}
+
 /******************************************************************************
  *
  * Named and typed setting routines

src/include/gpxe/settings.h

 			       long *value );
 extern int fetch_uint_setting ( struct settings *settings, unsigned int tag,
 				unsigned long *value );
+extern long fetch_intz_setting ( struct settings *settings, unsigned int tag );
+extern unsigned long fetch_uintz_setting ( struct settings *settings,
+					   unsigned int tag );
 extern struct settings * find_settings ( const char *name );
 extern int store_typed_setting ( struct settings *settings,
 				 unsigned int tag, struct setting_type *type,

src/usr/aoeboot.c

 #include <gpxe/ata.h>
 #include <gpxe/netdevice.h>
 #include <gpxe/dhcp.h>
+#include <gpxe/settings.h>
 #include <gpxe/abft.h>
 #include <int13.h>
 #include <usr/aoeboot.h>
 		container_of ( ata.backend, struct aoe_session, refcnt );
 	abft_fill_data ( aoe );
 
-	drive.drive = find_global_dhcp_num_option ( DHCP_EB_BIOS_DRIVE );
+	drive.drive = fetch_uintz_setting ( NULL, DHCP_EB_BIOS_DRIVE );
 	drive.blockdev = &ata.blockdev;
 
 	register_int13_drive ( &drive );

src/usr/autoboot.c

 #include <errno.h>
 #include <gpxe/netdevice.h>
 #include <gpxe/dhcp.h>
+#include <gpxe/settings.h>
 #include <gpxe/image.h>
 #include <gpxe/embedded.h>
 #include <usr/ifmgmt.h>
 		return rc;
 
 	/* Try to download and boot whatever we are given as a filename */
-	dhcp_snprintf ( buf, sizeof ( buf ),
-			find_global_dhcp_option ( DHCP_BOOTFILE_NAME ) );
+	fetch_string_setting ( NULL, DHCP_BOOTFILE_NAME, buf, sizeof ( buf ) );
 	if ( buf[0] ) {
 		printf ( "Booting from filename \"%s\"\n", buf );
 		return boot_filename ( buf );
 	}
 	
 	/* No filename; try the root path */
-	dhcp_snprintf ( buf, sizeof ( buf ),
-			find_global_dhcp_option ( DHCP_ROOT_PATH ) );
+	fetch_string_setting ( NULL, DHCP_ROOT_PATH, buf, sizeof ( buf ) );
 	if ( buf[0] ) {
 		printf ( "Booting from root path \"%s\"\n", buf );
 		return boot_root_path ( buf );

src/usr/iscsiboot.c

 #include <stdio.h>
 #include <gpxe/iscsi.h>
 #include <gpxe/dhcp.h>
+#include <gpxe/settings.h>
 #include <gpxe/netdevice.h>
 #include <gpxe/ibft.h>
 #include <int13.h>
 		goto error_init;
 	}
 
-	drive.drive = find_global_dhcp_num_option ( DHCP_EB_BIOS_DRIVE );
+	drive.drive = fetch_uintz_setting ( NULL, DHCP_EB_BIOS_DRIVE );
 	drive.blockdev = &scsi.blockdev;
 
 	/* FIXME: ugly, ugly hack */