MIPS: FW: Add environment variable processing.

Add parsing of the environment and command line variables passed to
the kernel to the firmware library.

Signed-off-by: Steven J. Hill <Steven.Hill@imgtec.com>

arch/mips/fw/lib/Makefile

@@ -2,4 +2,6 @@
 # Makefile for generic prom monitor library routines under Linux.
 #
 
+lib-y			+= cmdline.o
+
 lib-$(CONFIG_64BIT)	+= call_o32.o

arch/mips/fw/lib/cmdline.c

@@ -0,0 +1,101 @@
+/*
+ * This file is subject to the terms and conditions of the GNU General Public
+ * License.  See the file "COPYING" in the main directory of this archive
+ * for more details.
+ *
+ * Copyright (C) 2012 MIPS Technologies, Inc.  All rights reserved.
+ */
+#include <linux/init.h>
+#include <linux/kernel.h>
+#include <linux/string.h>
+
+#include <asm/addrspace.h>
+#include <asm/fw/fw.h>
+
+int fw_argc;
+int *_fw_argv;
+int *_fw_envp;
+
+void __init fw_init_cmdline(void)
+{
+	int i;
+
+	/* Validate command line parameters. */
+	if ((fw_arg0 >= CKSEG0) || (fw_arg1 < CKSEG0)) {
+		fw_argc = 0;
+		_fw_argv = NULL;
+	} else {
+		fw_argc = (fw_arg0 & 0x0000ffff);
+		_fw_argv = (int *)fw_arg1;
+	}
+
+	/* Validate environment pointer. */
+	if (fw_arg2 < CKSEG0)
+		_fw_envp = NULL;
+	else
+		_fw_envp = (int *)fw_arg2;
+
+	for (i = 1; i < fw_argc; i++) {
+		strlcat(arcs_cmdline, fw_argv(i), COMMAND_LINE_SIZE);
+		if (i < (fw_argc - 1))
+			strlcat(arcs_cmdline, " ", COMMAND_LINE_SIZE);
+	}
+}
+
+char * __init fw_getcmdline(void)
+{
+	return &(arcs_cmdline[0]);
+}
+
+char *fw_getenv(char *envname)
+{
+	char *result = NULL;
+
+	if (_fw_envp != NULL) {
+		/*
+		 * Return a pointer to the given environment variable.
+		 * YAMON uses "name", "value" pairs, while U-Boot uses
+		 * "name=value".
+		 */
+		int i, yamon, index = 0;
+
+		yamon = (strchr(fw_envp(index), '=') == NULL);
+		i = strlen(envname);
+
+		while (fw_envp(index)) {
+			if (strncmp(envname, fw_envp(index), i) == 0) {
+				if (yamon) {
+					result = fw_envp(index + 1);
+					break;
+				} else if (fw_envp(index)[i] == '=') {
+					result = (fw_envp(index + 1) + i);
+					break;
+				}
+			}
+
+			/* Increment array index. */
+			if (yamon)
+				index += 2;
+			else
+				index += 1;
+		}
+	}
+
+	return result;
+}
+
+unsigned long fw_getenvl(char *envname)
+{
+	unsigned long envl = 0UL;
+	char *str;
+	long val;
+	int tmp;
+
+	str = fw_getenv(envname);
+	if (str) {
+		tmp = kstrtol(str, 0, &val);
+		envl = (unsigned long)val;
+	}
+
+	return envl;
+}

arch/mips/include/asm/fw/fw.h

@@ -0,0 +1,47 @@
+/*
+ * This file is subject to the terms and conditions of the GNU General Public
+ * License.  See the file "COPYING" in the main directory of this archive
+ * for more details.
+ *
+ * Copyright (C) 2012 MIPS Technologies, Inc.
+ */
+#ifndef __ASM_FW_H_
+#define __ASM_FW_H_
+
+#include <asm/bootinfo.h>	/* For cleaner code... */
+
+enum fw_memtypes {
+	fw_dontuse,
+	fw_code,
+	fw_free,
+};
+
+typedef struct {
+	unsigned long base;	/* Within KSEG0 */
+	unsigned int size;	/* bytes */
+	enum fw_memtypes type;	/* fw_memtypes */
+} fw_memblock_t;
+
+/* Maximum number of memory block descriptors. */
+#define FW_MAX_MEMBLOCKS	32
+
+extern int fw_argc;
+extern int *_fw_argv;
+extern int *_fw_envp;
+
+/*
+ * Most firmware like YAMON, PMON, etc. pass arguments and environment
+ * variables as 32-bit pointers. These take care of sign extension.
+ */
+#define fw_argv(index)		((char *)(long)_fw_argv[(index)])
+#define fw_envp(index)		((char *)(long)_fw_envp[(index)])
+
+extern void fw_init_cmdline(void);
+extern char *fw_getcmdline(void);
+extern fw_memblock_t *fw_getmdesc(void);
+extern void fw_meminit(void);
+extern char *fw_getenv(char *name);
+extern unsigned long fw_getenvl(char *name);
+extern void fw_init_early_console(char port);
+
+#endif /* __ASM_FW_H_ */