common: add a grepenv command

u-boot environments, esp. when boards are shared across multiple
users, can get pretty large and time consuming to visually parse.
The grepenv command this patch adds can be used in lieu of printenv
to facilitate searching.  grepenv works like printenv but limits
its output only to environment strings (variable name and value
pairs) that match the user specified substring.

the following examples are on a board with a 5313 byte environment
that spans multiple screen pages:

Example 1:  summarize ethernet configuration:

=> grepenv eth TSEC
etact=FM1@DTSEC2
eth=FM1@DTSEC4
ethact=FM1@DTSEC2
eth1addr=00:E0:0C:00:8b:01
eth2addr=00:E0:0C:00:8b:02
eth3addr=00:E0:0C:00:8b:03
eth4addr=00:E0:0C:00:8b:04
eth5addr=00:E0:0C:00:8b:05
eth6addr=00:E0:0C:00:8b:06
eth7addr=00:E0:0C:00:8b:07
eth8addr=00:E0:0C:00:8b:08
eth9addr=00:E0:0C:00:8b:09
ethaddr=00:E0:0C:00:8b:00
netdev=eth0
uprcw=setenv ethact $eth;setenv filename p4080ds/R_PPSXX_0xe/rcw_0xe_2sgmii_rev2_high.bin;setenv start 0xe8000000;protect off all;run upimage;protect on all
upuboot=setenv ethact $eth;setenv filename u-boot.bin;setenv start eff80000;protect off all;run upimage;protect on all
upucode=setenv ethact $eth;setenv filename fsl_fman_ucode_P4080_101_6.bin;setenv start 0xef000000;protect off all;run upimage;protect on all
usdboot=setenv ethact $eth;tftp 1000000 $dir/$bootfile;tftp 2000000 $dir/initramfs.cpio.gz.uboot;tftp c00000 $dir/p4080ds-usdpaa.dtb;setenv bootargs root=/dev/ram rw console=ttyS0,115200 $othbootargs;bootm 1000000 2000000 c00000;
=>

Example 2: detect unused env vars:

=> grepenv etact
etact=FM1@DTSEC2
=>

Example 3: reveal hardcoded variables; e.g., for fdtaddr:

=> grepenv fdtaddr
fdtaddr=c00000
nfsboot=setenv bootargs root=/dev/nfs rw nfsroot=$serverip:$rootpath ip=$ipaddr:$serverip:$gatewayip:$netmask:$hostname:$netdev:off console=$consoledev,$baudrate $othbootargs;tftp $loadaddr $bootfile;tftp $fdtaddr $fdtfile;bootm $loadaddr - $fdtaddr
ramboot=setenv bootargs root=/dev/ram rw console=$consoledev,$baudrate $othbootargs;tftp $ramdiskaddr $ramdiskfile;tftp $loadaddr $bootfile;tftp $fdtaddr $fdtfile;bootm $loadaddr $ramdiskaddr $fdtaddr
=> grep $fdtaddr
fdtaddr=c00000
my_boot=bootm 0x40000000 0x41000000 0x00c00000
my_dtb=tftp 0x00c00000 $prefix/p4080ds.dtb
nohvboot=tftp 1000000 $dir/$bootfile;tftp 2000000 $dir/$ramdiskfile;tftp c00000 $dir/$fdtfile;setenv bootargs root=/dev/ram rw ramdisk_size=0x10000000 console=ttyS0,115200;bootm 1000000 2000000 c00000;
=>

This patch also enables the grepenv command by default on
corenet_ds based boards (and repositions the DHCP command
entry to keep the list sorted).

Signed-off-by: Kim Phillips <kim.phillips@freescale.com>
Cc: Kumar Gala <kumar.gala@freescale.com>
Cc: Andy Fleming <afleming@freescale.com>

README

@@ -646,6 +646,7 @@ The following options need to be configured:
 		CONFIG_CMD_FLASH	  flinfo, erase, protect
 		CONFIG_CMD_FPGA		  FPGA device initialization support
 		CONFIG_CMD_GO		* the 'go' command (exec code)
+		CONFIG_CMD_GREPENV	* search environment
 		CONFIG_CMD_HWFLOW	* RTS/CTS hw flow control
 		CONFIG_CMD_I2C		* I2C serial bus support
 		CONFIG_CMD_IDE		* IDE harddisk support

common/cmd_nvedit.c

@@ -4,7 +4,9 @@
  *
  * (C) Copyright 2001 Sysgo Real-Time Solutions, GmbH <www.elinos.com>
  * Andreas Heppel <aheppel@sysgo.de>
-
+ *
+ * Copyright 2011 Freescale Semiconductor, Inc.
+ *
  * See file CREDITS for list of people who contributed to this
  * project.
  *
@@ -160,6 +162,37 @@ int do_env_print (cmd_tbl_t *cmdtp, int flag, int argc, char * const argv[])
 	return rcode;
 }
 
+#ifdef CONFIG_CMD_GREPENV
+static int do_env_grep (cmd_tbl_t *cmdtp, int flag, int argc, char * const argv[])
+{
+	ENTRY *match;
+	unsigned char matched[env_htab.size / 8];
+	int rcode = 1, arg = 1, idx;
+
+	if (argc < 2)
+		return cmd_usage(cmdtp);
+
+	memset(matched, 0, env_htab.size / 8);
+
+	while (arg <= argc) {
+		idx = 0;
+		while ((idx = hstrstr_r(argv[arg], idx, &match, &env_htab))) {
+			if (!(matched[idx / 8] & (1 << (idx & 7)))) {
+				puts(match->key);
+				puts("=");
+				puts(match->data);
+				puts("\n");
+			}
+			matched[idx / 8] |= 1 << (idx & 7);
+			rcode = 0;
+		}
+		arg++;
+	}
+
+	return rcode;
+}
+#endif
+
 /*
  * Set a new environment variable,
  * or replace or delete an existing one.
@@ -829,6 +862,9 @@ static cmd_tbl_t cmd_env_sub[] = {
 #if defined(CONFIG_CMD_EXPORTENV)
 	U_BOOT_CMD_MKENT(export, 4, 0, do_env_export, "", ""),
 #endif
+#if defined(CONFIG_CMD_GREPENV)
+	U_BOOT_CMD_MKENT(grep, CONFIG_SYS_MAXARGS, 1, do_env_grep, "", ""),
+#endif
 #if defined(CONFIG_CMD_IMPORTENV)
 	U_BOOT_CMD_MKENT(import, 5, 0, do_env_import, "", ""),
 #endif
@@ -878,8 +914,11 @@ U_BOOT_CMD(
 #if defined(CONFIG_CMD_EDITENV)
 	"env edit name - edit environment variable\n"
 #endif
-	"env export [-t | -b | -c] addr [size] - export environmnt\n"
-	"env import [-d] [-t | -b | -c] addr [size] - import environmnt\n"
+	"env export [-t | -b | -c] addr [size] - export environment\n"
+#if defined(CONFIG_CMD_GREPENV)
+	"env grep string [...] - search environment\n"
+#endif
+	"env import [-d] [-t | -b | -c] addr [size] - import environment\n"
 	"env print [name ...] - print environment\n"
 #if defined(CONFIG_CMD_RUN)
 	"env run var [...] - run commands in an environment variable\n"
@@ -911,6 +950,16 @@ U_BOOT_CMD_COMPLETE(
 	var_complete
 );
 
+#ifdef CONFIG_CMD_GREPENV
+U_BOOT_CMD_COMPLETE(
+	grepenv, CONFIG_SYS_MAXARGS, 0,  do_env_grep,
+	"search environment variables",
+	"string ...\n"
+	"    - list environment name=value pairs matching 'string'",
+	var_complete
+);
+#endif
+
 U_BOOT_CMD_COMPLETE(
 	setenv, CONFIG_SYS_MAXARGS, 0,	do_env_set,
 	"set environment variables",

include/configs/corenet_ds.h

@@ -476,14 +476,15 @@
  */
 #include <config_cmd_default.h>
 
+#define CONFIG_CMD_DHCP
 #define CONFIG_CMD_ELF
 #define CONFIG_CMD_ERRATA
+#define CONFIG_CMD_GREPENV
 #define CONFIG_CMD_IRQ
 #define CONFIG_CMD_I2C
 #define CONFIG_CMD_MII
 #define CONFIG_CMD_PING
 #define CONFIG_CMD_SETEXPR
-#define CONFIG_CMD_DHCP
 
 #ifdef CONFIG_PCI
 #define CONFIG_CMD_PCI

include/search.h

@@ -80,6 +80,12 @@ extern int hsearch_r(ENTRY __item, ACTION __action, ENTRY ** __retval,
  */
 extern int hmatch_r(const char *__match, int __last_idx, ENTRY ** __retval,
 		    struct hsearch_data *__htab);
+/*
+ * Search for an entry whose key or data contains `MATCH'.  Otherwise,
+ * Same semantics as hsearch_r().
+ */
+extern int hstrstr_r(const char *__match, int __last_idx, ENTRY ** __retval,
+		    struct hsearch_data *__htab);
 
 /* Search and delete entry matching ITEM.key in internal hash table. */
 extern int hdelete_r(const char *__key, struct hsearch_data *__htab);

lib/hashtable.c

@@ -202,6 +202,29 @@ void hdestroy_r(struct hsearch_data *htab)
  *   example for functions like hdelete().
  */
 
+/*
+ * hstrstr_r - return index to entry whose key and/or data contains match
+ */
+int hstrstr_r(const char *match, int last_idx, ENTRY ** retval,
+	      struct hsearch_data *htab)
+{
+	unsigned int idx;
+
+	for (idx = last_idx + 1; idx < htab->size; ++idx) {
+		if (htab->table[idx].used <= 0)
+			continue;
+		if (strstr(htab->table[idx].entry.key, match) ||
+		    strstr(htab->table[idx].entry.data, match)) {
+			*retval = &htab->table[idx].entry;
+			return idx;
+		}
+	}
+
+	__set_errno(ESRCH);
+	*retval = NULL;
+	return 0;
+}
+
 int hmatch_r(const char *match, int last_idx, ENTRY ** retval,
 	     struct hsearch_data *htab)
 {