microblaze: Add FDT support

This patch adds FDT (flattened device tree) support to microblaze arch.

Tested with Linux arch/microblaze kernels with and without compiled in
FDT on Xilinx ML506 board.

Signed-off-by: Arun Bhanu <arun@bhanu.net>
Signed-off-by: Michal Simek <monstr@monstr.eu>

arch/microblaze/lib/bootm.c

@@ -35,22 +35,51 @@ DECLARE_GLOBAL_DATA_PTR;
 int do_bootm_linux(int flag, int argc, char *argv[], bootm_headers_t *images)
 {
 	/* First parameter is mapped to $r5 for kernel boot args */
-	void	(*theKernel) (char *);
+	void	(*theKernel) (char *, ulong, ulong);
 	char	*commandline = getenv ("bootargs");
+	ulong	rd_data_start, rd_data_end;
 
 	if ((flag != 0) && (flag != BOOTM_STATE_OS_GO))
 		return 1;
 
-	theKernel = (void (*)(char *))images->ep;
+	int	ret;
+
+	char	*of_flat_tree = NULL;
+#if defined(CONFIG_OF_LIBFDT)
+	ulong	of_size = 0;
+
+	/* find flattened device tree */
+	ret = boot_get_fdt (flag, argc, argv, images, &of_flat_tree, &of_size);
+	if (ret)
+		return 1;
+#endif
+
+	theKernel = (void (*)(char *, ulong, ulong))images->ep;
+
+	/* find ramdisk */
+	ret = boot_get_ramdisk (argc, argv, images, IH_ARCH_MICROBLAZE,
+			&rd_data_start, &rd_data_end);
+	if (ret)
+		return 1;
 
 	show_boot_progress (15);
 
+	if (!(ulong) of_flat_tree)
+		of_flat_tree = (char *)simple_strtoul (argv[3], NULL, 16);
+
 #ifdef DEBUG
-	printf ("## Transferring control to Linux (at address %08lx) ...\n",
-		(ulong) theKernel);
+	printf ("## Transferring control to Linux (at address 0x%08lx) " \
+				"ramdisk 0x%08lx, FDT 0x%08lx...\n",
+		(ulong) theKernel, rd_data_start, (ulong) of_flat_tree);
 #endif
 
-	theKernel (commandline);
+	/*
+	 * Linux Kernel Parameters (passing device tree):
+	 * r5: pointer to command line
+	 * r6: pointer to ramdisk
+	 * r7: pointer to the fdt, followed by the board info data
+	 */
+	theKernel (commandline, rd_data_start, (ulong) of_flat_tree);
 	/* does not return */
 
 	return 1;