sh: Add support zimageboot command for Renesas SH

Curent U-Boot can boot zImage by use the "go" command.
But this is not right method. And this method can not set command-line
to linux kernel.
zimageboot sets command-line in environment of u-boot in linux kernel,
and provides function to boot it.

Signed-off-by: Nobuhiro Iwamatsu <nobuhiro.iwamatsu.yj@renesas.com>

arch/sh/lib/Makefile

@@ -31,6 +31,9 @@ COBJS-y	+= time_sh2.o
 else
 COBJS-y	+= time.o
 endif
+ifeq ($(CONFIG_CMD_SH_ZIMAGEBOOT),y)
+COBJS-y += zimageboot.o
+endif
 
 SRCS	:= $(SOBJS-y:.o=.S) $(COBJS-y:.o=.c)
 OBJS	:= $(addprefix $(obj),$(SOBJS-y) $(COBJS-y))

arch/sh/lib/zimageboot.c

@@ -0,0 +1,80 @@
+/*
+ * (C) Copyright 2010
+ *   Renesas Solutions Corp.
+ *   Nobuhiro Iwamatsu <nobuhiro.iwamatsu.yj@renesas.com>
+ *
+ * See file CREDITS for list of people who contributed to this
+ * project.
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public License as
+ * published by the Free Software Foundation; either version 2 of
+ * the License, or (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software
+ * Foundation, Inc., 59 Temple Place, Suite 330, Boston,
+ * MA 02111-1307 USA
+ */
+
+/*
+ * Linux SuperH zImage loading and boot
+ */
+
+#include <common.h>
+#include <asm/io.h>
+#include <asm/zimage.h>
+
+int do_sh_zimageboot (cmd_tbl_t *cmdtp, int flag, int argc, char * const argv[])
+{
+	ulong (*zboot_entry)(int, char * const []) = NULL;
+	char *s0, *s1;
+	unsigned char *param = NULL;
+	char *cmdline;
+	char *bootargs;
+
+	disable_interrupts();
+
+	if (argc >= 3) {
+		/* argv[1] holds the address of the zImage */
+		s0 = argv[1];
+		/* argv[2] holds the address of zero page */
+		s1 = argv[2];
+	} else {
+		goto exit;
+	}
+
+	if (s0)
+		zboot_entry = (ulong (*)(int, char * const []))simple_strtoul(s0, NULL, 16);
+
+	/* empty_zero_page */
+	if (s1)
+		param = (unsigned char*)simple_strtoul(s1, NULL, 16);
+
+	/* Linux kernel command line */
+	cmdline = (char *)param + COMMAND_LINE;
+	bootargs = getenv("bootargs");
+
+	/* Clear zero page */
+	memset(param, 0, 0x1000);
+
+	/* Set commandline */
+	strcpy(cmdline, bootargs);
+
+	/* Boot */
+	zboot_entry(0, NULL);
+
+exit:
+	return -1;
+}
+
+U_BOOT_CMD(
+	zimageboot, 3, 0,	do_sh_zimageboot,
+	"Boot zImage for Renesas SH",
+	""
+);