pxe: add AArch64 image support

The sysboot and pxe commands currently support either U-Boot formats or
raw zImages. Add support for the AArch64 Linux port's native image format
too.

As with zImage support, there is no auto-detection of the native image
format. Rather, if the image is auto-detected as a U-Boot format, U-Boot
will try to interpret it as such. Otherwise, U-Boot will fall back to a
raw/native image format, if one is enabled.

My belief is that CONFIG_CMD_BOOTZ won't ever be enabled for any AArch64
port, hence there's never a need to differentiate between CONFIG_CMD_
_BOOTI and _BOOTZ at run-time; compile-time will do. Even if this isn't
true, we want to prefer _BOOTI over _BOOTZ when defined, since _BOOTI is
definitely the native format for AArch64.

Change-Id: I83c5cc7566032afd72516de46f4e5eb7a780284a
Signed-off-by: Stephen Warren <swarren@nvidia.com>
Signed-off-by: Tom Warren <twarren@nvidia.com>

common/cmd_pxe.c

@@ -793,8 +793,12 @@ static int label_boot(cmd_tbl_t *cmdtp, struct pxe_label *label)
 	/* Try bootm for legacy and FIT format image */
 	if (genimg_get_format(buf) != IMAGE_FORMAT_INVALID)
 		do_bootm(cmdtp, 0, bootm_argc, bootm_argv);
-#ifdef CONFIG_CMD_BOOTZ
-	/* Try booting a zImage */
+#ifdef CONFIG_CMD_BOOTI
+	/* Try booting an AArch64 Linux kernel image */
+	else
+		do_booti(cmdtp, 0, bootm_argc, bootm_argv);
+#elif defined(CONFIG_CMD_BOOTZ)
+	/* Try booting a Image */
 	else
 		do_bootz(cmdtp, 0, bootm_argc, bootm_argv);
 #endif

include/command.h

@@ -104,6 +104,8 @@ static inline int bootm_maybe_autostart(cmd_tbl_t *cmdtp, const char *cmd)
 
 extern int do_bootz(cmd_tbl_t *cmdtp, int flag, int argc, char * const argv[]);
 
+extern int do_booti(cmd_tbl_t *cmdtp, int flag, int argc, char * const argv[]);
+
 extern int common_diskboot(cmd_tbl_t *cmdtp, const char *intf, int argc,
 			   char *const argv[]);