u-boot/common/command.c
Wolfgang Denk ea882baf9c New implementation for internal handling of environment variables.
Motivation:

* Old environment code used a pessimizing implementation:
  - variable lookup used linear search => slow
  - changed/added variables were added at the end, i. e. most
    frequently used variables had the slowest access times => slow
  - each setenv() would calculate the CRC32 checksum over the whole
    environment block => slow
* "redundant" envrionment was locked down to two copies
* No easy way to implement features like "reset to factory defaults",
  or to select one out of several pre-defined (previously saved) sets
  of environment settings ("profiles")
* No easy way to import or export environment settings

======================================================================

API Changes:

- Variable names starting with '#' are no longer allowed

  I didn't find any such variable names being used; it is highly
  recommended to follow standard conventions and start variable names
  with an alphanumeric character

- "printenv" will now print a backslash at the end of all but the last
  lines of a multi-line variable value.

  Multi-line variables have never been formally defined, allthough
  there is no reason not to use them. Now we define rules how to deal
  with them, allowing for import and export.

- Function forceenv() and the related code in saveenv() was removed.
  At the moment this is causing build problems for the only user of
  this code (schmoogie - which has no entry in MAINTAINERS); may be
  fixed later by implementing the "env set -f" feature.

Inconsistencies:

- "printenv" will '\\'-escape the '\n' in multi-line variables, while
  "printenv var" will not do that.

======================================================================

Advantages:

- "printenv" output much better readable (sorted)
- faster!
- extendable (additional variable properties can be added)
- new, powerful features like "factory reset" or easy switching
  between several different environment settings ("profiles")

Disadvantages:

- Image size grows by typically 5...7 KiB (might shrink a bit again on
  systems with redundant environment with a following patch series)

======================================================================

Implemented:

- env command with subcommands:

  - env print [arg ...]

    same as "printenv": print environment

  - env set [-f] name [arg ...]

    same as "setenv": set (and delete) environment variables

    ["-f" - force setting even for read-only variables - not
    implemented yet.]

  - end delete [-f] name

    not implemented yet

    ["-f" - force delete even for read-only variables]

  - env save

    same as "saveenv": save environment

  - env export [-t | -b | -c] addr [size]

    export internal representation (hash table) in formats usable for
    persistent storage or processing:

	-t:	export as text format; if size is given, data will be
		padded with '\0' bytes; if not, one terminating '\0'
		will be added (which is included in the "filesize"
		setting so you can for exmple copy this to flash and
		keep the termination).
	-b:	export as binary format (name=value pairs separated by
		'\0', list end marked by double "\0\0")
	-c:	export as checksum protected environment format as
		used for example by "saveenv" command
	addr:	memory address where environment gets stored
	size:	size of output buffer

	With "-c" and size is NOT given, then the export command will
	format the data as currently used for the persistent storage,
	i. e. it will use CONFIG_ENV_SECT_SIZE as output block size and
	prepend a valid CRC32 checksum and, in case of resundant
	environment, a "current" redundancy flag. If size is given, this
	value will be used instead of CONFIG_ENV_SECT_SIZE; again, CRC32
	checksum and redundancy flag will be inserted.

	With "-b" and "-t", always only the real data (including a
	terminating '\0' byte) will be written; here the optional size
	argument will be used to make sure not to overflow the user
	provided buffer; the command will abort if the size is not
	sufficient. Any remainign space will be '\0' padded.

        On successful return, the variable "filesize" will be set.
        Note that filesize includes the trailing/terminating '\0'
        byte(s).

        Usage szenario: create a text snapshot/backup of the current
	settings:

		=> env export -t 100000
		=> era ${backup_addr} +${filesize}
		=> cp.b 100000 ${backup_addr} ${filesize}

	Re-import this snapshot, deleting all other settings:

		=> env import -d -t ${backup_addr}

  - env import [-d] [-t | -b | -c] addr [size]

    import external format (text or binary) into hash table,
    optionally deleting existing values:

	-d:	delete existing environment before importing;
		otherwise overwrite / append to existion definitions
	-t:	assume text format; either "size" must be given or the
		text data must be '\0' terminated
	-b:	assume binary format ('\0' separated, "\0\0" terminated)
	-c:	assume checksum protected environment format
	addr:	memory address to read from
	size:	length of input data; if missing, proper '\0'
		termination is mandatory

  - env default -f

    reset default environment: drop all environment settings and load
    default environment

  - env ask name [message] [size]

    same as "askenv": ask for environment variable

  - env edit name

    same as "editenv": edit environment variable

  - env run

    same as "run": run commands in an environment variable

======================================================================

TODO:

- drop default env as implemented now; provide a text file based
  initialization instead (eventually using several text files to
  incrementally build it from common blocks) and a tool to convert it
  into a binary blob / object file.

- It would be nice if we could add wildcard support for environment
  variables; this is needed for variable name auto-completion,
  but it would also be nice to be able to say "printenv ip*" or
  "printenv *addr*"

- Some boards don't link any more due to the grown code size:
  DU405, canyonlands, sequoia, socrates.

	=> cc: Matthias Fuchs <matthias.fuchs@esd-electronics.com>,
	       Stefan Roese <sr@denx.de>,
	       Heiko Schocher <hs@denx.de>

- Dropping forceenv() causes build problems on schmoogie

	=> cc: Sergey Kubushyn <ksi@koi8.net>

- Build tested on PPC and ARM only; runtime tested with NOR and NAND
  flash only => needs testing!!

Signed-off-by: Wolfgang Denk <wd@denx.de>
Cc: Matthias Fuchs <matthias.fuchs@esd-electronics.com>,
Cc: Stefan Roese <sr@denx.de>,
Cc: Heiko Schocher <hs@denx.de>
Cc: Sergey Kubushyn <ksi@koi8.net>
2010-09-19 19:29:48 +02:00

467 lines
9.8 KiB
C

/*
* (C) Copyright 2000-2009
* Wolfgang Denk, DENX Software Engineering, wd@denx.de.
*
* 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
*/
/*
* Command Processor Table
*/
#include <common.h>
#include <command.h>
/*
* Use puts() instead of printf() to avoid printf buffer overflow
* for long help messages
*/
int _do_help (cmd_tbl_t *cmd_start, int cmd_items, cmd_tbl_t * cmdtp, int
flag, int argc, char * const argv[])
{
int i;
int rcode = 0;
if (argc == 1) { /*show list of commands */
cmd_tbl_t *cmd_array[cmd_items];
int i, j, swaps;
/* Make array of commands from .uboot_cmd section */
cmdtp = cmd_start;
for (i = 0; i < cmd_items; i++) {
cmd_array[i] = cmdtp++;
}
/* Sort command list (trivial bubble sort) */
for (i = cmd_items - 1; i > 0; --i) {
swaps = 0;
for (j = 0; j < i; ++j) {
if (strcmp (cmd_array[j]->name,
cmd_array[j + 1]->name) > 0) {
cmd_tbl_t *tmp;
tmp = cmd_array[j];
cmd_array[j] = cmd_array[j + 1];
cmd_array[j + 1] = tmp;
++swaps;
}
}
if (!swaps)
break;
}
/* print short help (usage) */
for (i = 0; i < cmd_items; i++) {
const char *usage = cmd_array[i]->usage;
/* allow user abort */
if (ctrlc ())
return 1;
if (usage == NULL)
continue;
printf("%-*s- %s\n", CONFIG_SYS_HELP_CMD_WIDTH,
cmd_array[i]->name, usage);
}
return 0;
}
/*
* command help (long version)
*/
for (i = 1; i < argc; ++i) {
if ((cmdtp = find_cmd_tbl (argv[i], cmd_start, cmd_items )) != NULL) {
rcode |= cmd_usage(cmdtp);
} else {
printf ("Unknown command '%s' - try 'help'"
" without arguments for list of all"
" known commands\n\n", argv[i]
);
rcode = 1;
}
}
return rcode;
}
/***************************************************************************
* find command table entry for a command
*/
cmd_tbl_t *find_cmd_tbl (const char *cmd, cmd_tbl_t *table, int table_len)
{
cmd_tbl_t *cmdtp;
cmd_tbl_t *cmdtp_temp = table; /*Init value */
const char *p;
int len;
int n_found = 0;
/*
* Some commands allow length modifiers (like "cp.b");
* compare command name only until first dot.
*/
len = ((p = strchr(cmd, '.')) == NULL) ? strlen (cmd) : (p - cmd);
for (cmdtp = table;
cmdtp != table + table_len;
cmdtp++) {
if (strncmp (cmd, cmdtp->name, len) == 0) {
if (len == strlen (cmdtp->name))
return cmdtp; /* full match */
cmdtp_temp = cmdtp; /* abbreviated command ? */
n_found++;
}
}
if (n_found == 1) { /* exactly one match */
return cmdtp_temp;
}
return NULL; /* not found or ambiguous command */
}
cmd_tbl_t *find_cmd (const char *cmd)
{
int len = &__u_boot_cmd_end - &__u_boot_cmd_start;
return find_cmd_tbl(cmd, &__u_boot_cmd_start, len);
}
int cmd_usage(cmd_tbl_t *cmdtp)
{
printf("%s - %s\n\n", cmdtp->name, cmdtp->usage);
#ifdef CONFIG_SYS_LONGHELP
printf("Usage:\n%s ", cmdtp->name);
if (!cmdtp->help) {
puts ("- No additional help available.\n");
return 1;
}
puts (cmdtp->help);
putc ('\n');
#endif /* CONFIG_SYS_LONGHELP */
return 1;
}
#ifdef CONFIG_AUTO_COMPLETE
int var_complete(int argc, char * const argv[], char last_char, int maxv, char *cmdv[])
{
#if 0 /* need to reimplement */
static char tmp_buf[512];
int space;
space = last_char == '\0' || last_char == ' ' || last_char == '\t';
if (space && argc == 1)
return env_complete("", maxv, cmdv, sizeof(tmp_buf), tmp_buf);
if (!space && argc == 2)
return env_complete(argv[1], maxv, cmdv, sizeof(tmp_buf), tmp_buf);
#endif
return 0;
}
static void install_auto_complete_handler(const char *cmd,
int (*complete)(int argc, char * const argv[], char last_char, int maxv, char *cmdv[]))
{
cmd_tbl_t *cmdtp;
cmdtp = find_cmd(cmd);
if (cmdtp == NULL)
return;
cmdtp->complete = complete;
}
void install_auto_complete(void)
{
#if defined(CONFIG_CMD_EDITENV)
install_auto_complete_handler("editenv", var_complete);
#endif
install_auto_complete_handler("printenv", var_complete);
install_auto_complete_handler("setenv", var_complete);
#if defined(CONFIG_CMD_RUN)
install_auto_complete_handler("run", var_complete);
#endif
}
/*************************************************************************************/
static int complete_cmdv(int argc, char * const argv[], char last_char, int maxv, char *cmdv[])
{
cmd_tbl_t *cmdtp;
const char *p;
int len, clen;
int n_found = 0;
const char *cmd;
/* sanity? */
if (maxv < 2)
return -2;
cmdv[0] = NULL;
if (argc == 0) {
/* output full list of commands */
for (cmdtp = &__u_boot_cmd_start; cmdtp != &__u_boot_cmd_end; cmdtp++) {
if (n_found >= maxv - 2) {
cmdv[n_found++] = "...";
break;
}
cmdv[n_found++] = cmdtp->name;
}
cmdv[n_found] = NULL;
return n_found;
}
/* more than one arg or one but the start of the next */
if (argc > 1 || (last_char == '\0' || last_char == ' ' || last_char == '\t')) {
cmdtp = find_cmd(argv[0]);
if (cmdtp == NULL || cmdtp->complete == NULL) {
cmdv[0] = NULL;
return 0;
}
return (*cmdtp->complete)(argc, argv, last_char, maxv, cmdv);
}
cmd = argv[0];
/*
* Some commands allow length modifiers (like "cp.b");
* compare command name only until first dot.
*/
p = strchr(cmd, '.');
if (p == NULL)
len = strlen(cmd);
else
len = p - cmd;
/* return the partial matches */
for (cmdtp = &__u_boot_cmd_start; cmdtp != &__u_boot_cmd_end; cmdtp++) {
clen = strlen(cmdtp->name);
if (clen < len)
continue;
if (memcmp(cmd, cmdtp->name, len) != 0)
continue;
/* too many! */
if (n_found >= maxv - 2) {
cmdv[n_found++] = "...";
break;
}
cmdv[n_found++] = cmdtp->name;
}
cmdv[n_found] = NULL;
return n_found;
}
static int make_argv(char *s, int argvsz, char *argv[])
{
int argc = 0;
/* split into argv */
while (argc < argvsz - 1) {
/* skip any white space */
while ((*s == ' ') || (*s == '\t'))
++s;
if (*s == '\0') /* end of s, no more args */
break;
argv[argc++] = s; /* begin of argument string */
/* find end of string */
while (*s && (*s != ' ') && (*s != '\t'))
++s;
if (*s == '\0') /* end of s, no more args */
break;
*s++ = '\0'; /* terminate current arg */
}
argv[argc] = NULL;
return argc;
}
static void print_argv(const char *banner, const char *leader, const char *sep, int linemax, char * const argv[])
{
int ll = leader != NULL ? strlen(leader) : 0;
int sl = sep != NULL ? strlen(sep) : 0;
int len, i;
if (banner) {
puts("\n");
puts(banner);
}
i = linemax; /* force leader and newline */
while (*argv != NULL) {
len = strlen(*argv) + sl;
if (i + len >= linemax) {
puts("\n");
if (leader)
puts(leader);
i = ll - sl;
} else if (sep)
puts(sep);
puts(*argv++);
i += len;
}
printf("\n");
}
static int find_common_prefix(char * const argv[])
{
int i, len;
char *anchor, *s, *t;
if (*argv == NULL)
return 0;
/* begin with max */
anchor = *argv++;
len = strlen(anchor);
while ((t = *argv++) != NULL) {
s = anchor;
for (i = 0; i < len; i++, t++, s++) {
if (*t != *s)
break;
}
len = s - anchor;
}
return len;
}
static char tmp_buf[CONFIG_SYS_CBSIZE]; /* copy of console I/O buffer */
int cmd_auto_complete(const char *const prompt, char *buf, int *np, int *colp)
{
int n = *np, col = *colp;
char *argv[CONFIG_SYS_MAXARGS + 1]; /* NULL terminated */
char *cmdv[20];
char *s, *t;
const char *sep;
int i, j, k, len, seplen, argc;
int cnt;
char last_char;
if (strcmp(prompt, CONFIG_SYS_PROMPT) != 0)
return 0; /* not in normal console */
cnt = strlen(buf);
if (cnt >= 1)
last_char = buf[cnt - 1];
else
last_char = '\0';
/* copy to secondary buffer which will be affected */
strcpy(tmp_buf, buf);
/* separate into argv */
argc = make_argv(tmp_buf, sizeof(argv)/sizeof(argv[0]), argv);
/* do the completion and return the possible completions */
i = complete_cmdv(argc, argv, last_char, sizeof(cmdv)/sizeof(cmdv[0]), cmdv);
/* no match; bell and out */
if (i == 0) {
if (argc > 1) /* allow tab for non command */
return 0;
putc('\a');
return 1;
}
s = NULL;
len = 0;
sep = NULL;
seplen = 0;
if (i == 1) { /* one match; perfect */
k = strlen(argv[argc - 1]);
s = cmdv[0] + k;
len = strlen(s);
sep = " ";
seplen = 1;
} else if (i > 1 && (j = find_common_prefix(cmdv)) != 0) { /* more */
k = strlen(argv[argc - 1]);
j -= k;
if (j > 0) {
s = cmdv[0] + k;
len = j;
}
}
if (s != NULL) {
k = len + seplen;
/* make sure it fits */
if (n + k >= CONFIG_SYS_CBSIZE - 2) {
putc('\a');
return 1;
}
t = buf + cnt;
for (i = 0; i < len; i++)
*t++ = *s++;
if (sep != NULL)
for (i = 0; i < seplen; i++)
*t++ = sep[i];
*t = '\0';
n += k;
col += k;
puts(t - k);
if (sep == NULL)
putc('\a');
*np = n;
*colp = col;
} else {
print_argv(NULL, " ", " ", 78, cmdv);
puts(prompt);
puts(buf);
}
return 1;
}
#endif
#ifdef CMD_DATA_SIZE
int cmd_get_data_size(char* arg, int default_size)
{
/* Check for a size specification .b, .w or .l.
*/
int len = strlen(arg);
if (len > 2 && arg[len-2] == '.') {
switch(arg[len-1]) {
case 'b':
return 1;
case 'w':
return 2;
case 'l':
return 4;
case 's':
return -2;
default:
return -1;
}
}
return default_size;
}
#endif