Commit graph

69 commits

Author SHA1 Message Date
Tom Rini
83d290c56f SPDX: Convert all of our single license tags to Linux Kernel style
When U-Boot started using SPDX tags we were among the early adopters and
there weren't a lot of other examples to borrow from.  So we picked the
area of the file that usually had a full license text and replaced it
with an appropriate SPDX-License-Identifier: entry.  Since then, the
Linux Kernel has adopted SPDX tags and they place it as the very first
line in a file (except where shebangs are used, then it's second line)
and with slightly different comment styles than us.

In part due to community overlap, in part due to better tag visibility
and in part for other minor reasons, switch over to that style.

This commit changes all instances where we have a single declared
license in the tag as both the before and after are identical in tag
contents.  There's also a few places where I found we did not have a tag
and have introduced one.

Signed-off-by: Tom Rini <trini@konsulko.com>
2018-05-07 09:34:12 -04:00
Siva Durga Prasad Paladugu
7bcdf19572 env: Relocate env drivers if manual reloc is required
Relocate env drivers if manual relocation is enabled. This
patch fixes the issue of u-boot hang incase if env is
present in any of the flash devices.

Signed-off-by: Siva Durga Prasad Paladugu <sivadur@xilinx.com>
Signed-off-by: Michal Simek <michal.simek@xilinx.com>
Reviewed-by: Simon Glass <sjg@chromium.org>
2018-04-16 18:45:35 -04:00
Alex Kiernan
9925f1dbc3 net: Move enetaddr env access code to env config instead of net config
In order that we can use eth_env_* even when CONFIG_NET isn't set, move
these functions to environment code from net code.

This fixes failures such as:

  board/ti/am335x/built-in.o: In function `board_late_init':
  board/ti/am335x/board.c:752: undefined reference to `eth_env_set_enetaddr'
  u-boot/board/ti/am335x/board.c:766: undefined reference to `eth_env_set_enetaddr'

which caters for use cases such as:

commit f411b5cca4 ("board: am335x: Always set eth/eth1addr environment
variable")

when Ethernet is required in Linux, but not U-Boot.

Signed-off-by: Alex Kiernan <alex.kiernan@gmail.com>
2018-04-08 23:00:58 -04:00
Goldschmidt Simon
b2cdef4861 env: restore old env_get_char() behaviour
With multiple environments, the 'get_char' callback for env
drivers does not really make sense any more because it is
only supported by two drivers (eeprom and nvram).

To restore single character loading for these drivers,
override 'env_get_char_spec'.

Signed-off-by: Simon Goldschmidt <sgoldschmidt@de.pepperl-fuchs.com>
Acked-by: Maxime Ripard <maxime.ripard@bootlin.com>
2018-02-16 11:12:42 -05:00
York Sun
e1caa5841e env: Fix env_load_location
Commit 7d714a24d7 ("env: Support multiple environments") added
static variable env_load_location. When saving environmental
variables, this variable is presumed to have the value set before.
In case the value was set before relocation and U-Boot runs from a
NOR flash, this variable wasn't writable. This causes failure when
saving the environment. To save this location, global data must be
used instead.

Signed-off-by: York Sun <york.sun@nxp.com>
CC: Maxime Ripard <maxime.ripard@free-electrons.com>
2018-02-16 11:12:41 -05:00
Simon Goldschmidt
31f044bd91 env: move more common code to env_import_redund
There is more common code in mmc, nand and ubi env drivers that
can be shared by moving to env_import_redund.

For this, a status/error value whether the buffers were loaded
are passed as additional parameters to env_import_redund.
Ideally, these are already returned to the env driver by the
storage driver. This is the case for mmc, nand and ubi, so for
this change, code deduplicated.

Signed-off-by: Simon Goldschmidt <sgoldschmidt@de.pepperl-fuchs.com>
Acked-by: Maxime Ripard <maxime.ripard@free-electrons.com>
2018-02-01 08:05:49 -05:00
Maxime Ripard
8a3a7e2270 env: Pass additional parameters to the env lookup function
In preparation for the multiple environment support, let's introduce two
new parameters to the environment driver lookup function: the priority and
operation.

The operation parameter is meant to identify, obviously, the operation you
might want to perform on the environment.

The priority is a number passed to identify the environment priority you
want to retrieve. The lowest priority parameter (0) will be the primary
source.

Combining the two parameters allow you to support multiple environments
through different priorities, and to change those priorities between read
and writes operations.

This is especially useful to implement migration mechanisms where you want
to always use the same environment first, be it to read or write, while the
common case is more likely to use the same environment it has read from to
write it to.

Signed-off-by: Maxime Ripard <maxime.ripard@free-electrons.com>
2018-01-27 09:19:11 -05:00
Maxime Ripard
9c24dfb2b8 cmd: nvedit: Get rid of the env lookup
The nvedit command is the only user of env_driver_lookup_default outside of
the environment code itself, and it uses it only to print the environment
it's about to save to during env save.

As we're about to rework the environment to be able to handle multiple
environment sources, we might not have an idea of what environment backend
is going to be used before trying (and possibly failing for some).

Therefore, it makes sense to remove that message and move it to the
env_save function itself. As a side effect, we also can get rid of the call
to env_driver_lookup_default that is also about to get refactored.

Reviewed-by: Andre Przywara <andre.przywara@arm.com>
Reviewed-by: Lukasz Majewski <lukma@denx.de>
Reviewed-by: Simon Glass <sjg@chromium.org>
Signed-off-by: Maxime Ripard <maxime.ripard@free-electrons.com>
2018-01-27 09:19:11 -05:00
Tom Rini
c6831c74a9 env: Remove CONFIG_ENV_AES support
This support has been deprecated since v2017.09 due to security issues.
We now remove this support.

Signed-off-by: Tom Rini <trini@konsulko.com>
2017-11-21 07:43:31 -05:00
Tuomas Tynkkynen
7b7341d7f3 env: Drop CONFIG_ENV_IS_IN_DATAFLASH
Last user of this option went away in commit:

fdc7718999 ("board: usb_a9263: Update to support DT and DM")

Signed-off-by: Tuomas Tynkkynen <tuomas.tynkkynen@iki.fi>
2017-10-16 09:42:51 -04:00
Simon Glass
c595199194 env: Adjust the load() method to return an error
The load() methods have inconsistent behaviour on error. Some of them load
an empty default environment. Some load an environment containing an error
message. Others do nothing.

As a step in the right direction, have the method return an error code.
Then the caller could handle this itself in a consistent way.

Signed-off-by: Simon Glass <sjg@chromium.org>
2017-08-16 08:31:24 -04:00
Simon Glass
21f639446d env: Adjust the get_char() method to return an int
In principle this can fail, e.g. if the index is out of range. Adjust the
driver signature to allow returning an error code.

Signed-off-by: Simon Glass <sjg@chromium.org>
Reviewed-by: Tom Rini <trini@konsulko.com>
2017-08-16 08:31:24 -04:00
Simon Glass
723806cc5b env: Rename some other getenv()-related functions
We are now using an env_ prefix for environment functions. Rename these
other functions as well, for consistency:

   getenv_vlan()
   getenv_bootm_size()
   getenv_bootm_low()
   getenv_bootm_mapsize()
   env_get_default()

Suggested-by: Wolfgang Denk <wd@denx.de>
Signed-off-by: Simon Glass <sjg@chromium.org>
2017-08-16 08:31:11 -04:00
Simon Glass
01510091de env: Drop saveenv() in favour of env_save()
Use the env_save() function directly now that there is only one
implementation of saveenv().

Signed-off-by: Simon Glass <sjg@chromium.org>
Reviewed-by: Wolfgang Denk <wd@denx.de>
Reviewed-by: Tom Rini <trini@konsulko.com>
2017-08-15 20:50:30 -04:00
Simon Glass
310fb14b26 env: Drop env_relocate_spec() in favour of env_load()
This is a strange name for a function that loads the environment. There is
now only one implementation of this function, so use the new env_load()
function directly instead.

Signed-off-by: Simon Glass <sjg@chromium.org>
Reviewed-by: Tom Rini <trini@konsulko.com>
2017-08-15 20:50:29 -04:00
Simon Glass
a69d0f60e5 env: Drop env_get_char_spec()
We only have a single implementation of this function now and it is called
env_get_char(). Drop the old function and the weak version.

Reviewed-by: Tom Rini <trini@konsulko.com>
Signed-off-by: Simon Glass <sjg@chromium.org>
2017-08-15 20:50:29 -04:00
Simon Glass
ac358beb85 env: Drop the env_name_spec global
Add a name to the driver and use that instead of the global variable
declared by each driver.

Signed-off-by: Simon Glass <sjg@chromium.org>
Reviewed-by: Tom Rini <trini@konsulko.com>
2017-08-15 20:50:28 -04:00
Simon Glass
7938822a6b env: Drop common init() functions
Most of the init() implementations just use the default environment.
Adjust env_init_new() to do this automatically, and drop the redundant
code.

Signed-off-by: Simon Glass <sjg@chromium.org>
Reviewed-by: Tom Rini <trini@konsulko.com>
2017-08-15 20:50:27 -04:00
Simon Glass
4415f1d1f1 env: Create a location driver for each location
Set up a location driver for each supported environment location. At
present this just points to the global functions and is not used. A
later patch will switch this over to use private functions in each driver.

There are several special cases here in various drivers to handle
peculiarities of certain boards:

1. Some boards define CONFIG_ENV_IS_IN_FAT and CONFIG_SPL_ENV_SUPPORT but
do not actually load the environment in SPL. The env load code was
optimised out before but with the driver, it is not. Therefore a special
case is added to env/fat.c. The correct fix (depending on board testing
might be to disable CONFIG_SPL_ENV_SUPPORT.

2. A similar situations happens with CONFIG_ENV_IS_IN_FLASH. Some boards
do not actually load the environment in SPL, so to reduce code size we
need to drop that code. A similar fix may be possible with these boards,
or it may be possible to adjust the environment CONFIG settings.

Added to the above is that the CONFIG_SPL_ENV_SUPPORT option does not
apply when the environment is in flash.

Obviously the above has been discovered through painful and time-consuming
trial and error. Hopefully board maintainers can take a look and figure
out what is actually needed.

Signed-off-by: Simon Glass <sjg@chromium.org>
2017-08-15 08:18:53 -04:00
Simon Glass
203e94f6c9 env: Add an enum for environment state
At present we have three states for the environment, numbered 0, 1 and 2.
Add an enum to record this to avoid open-coded values.

Signed-off-by: Simon Glass <sjg@chromium.org>
Reviewed-by: Tom Rini <trini@konsulko.com>
2017-08-15 08:18:51 -04:00
Simon Glass
bcdfb8d5a5 env: common: Make env_get_addr/get_char_memory() static
These functions are not used outside this file. Make them static and order
them to avoid forward declarations.

Signed-off-by: Simon Glass <sjg@chromium.org>
Reviewed-by: Tom Rini <trini@konsulko.com>
2017-08-15 08:18:46 -04:00
Fiach Antaw
76768f5f08 env: Add generic redundant environment implementation
All current environments that implement redundancy use almost
identical implementations. This patch implements the env_nand
implementation as a function in env_common, and updates the
env_export function to export an env_nand-style 'flags' field by
default.

Signed-off-by: Fiach Antaw <fiach.antaw@uqconnect.edu.au>
Reviewed-by: Tom Rini <trini@konsulko.com>
2017-07-22 15:36:17 -04:00
Maxime Ripard
fb1c43cc37 common: Move environment choice to Kconfig
The environment location is something that might change per board
(depending on what storage options are availaible there) or depending on
the user choice (when we have several options).

Instead of hardcoding it in our configuration header, create a Kconfig
choice with the options we use for now, and the symbols that depend on it.

Once done, also remove the irrelevant sunxi defines.

Signed-off-by: Maxime Ripard <maxime.ripard@free-electrons.com>
Reviewed-by: Tom Rini <trini@konsulko.com>
Reviewed-by: Jagan Teki <jagan@openedev.com>
2017-04-07 11:23:45 +05:30
Robert P. J. Day
fc0b5948e0 Various, accumulated typos collected from around the tree.
Fix various misspellings of:

 * deprecated
 * partition
 * preceding,preceded
 * preparation
 * its versus it's
 * export
 * existing
 * scenario
 * redundant
 * remaining
 * value
 * architecture

Signed-off-by: Robert P. J. Day <rpjday@crashcourse.ca>
Reviewed-by: Jagan Teki <jteki@openedev.com>
Reviewed-by: Stefan Roese <sr@denx.de>
2016-10-06 20:57:40 -04:00
Dmitry Lifshitz
6e7b7df4df env_mmc: support env partition setup in runtime
Add callback with __weak annotation to allow setup of environment
partition number in runtime from a board file.

Propagate mmc_switch_part() return value into init_mmc_for_env() instead
of -1 in case of failure.

Signed-off-by: Dmitry Lifshitz <lifshitz@compulab.co.il>
Signed-off-by: Igor Grinberg <grinberg@compulab.co.il>
Acked-by: Pantelis Antoniou <panto@antoniou-consulting.com>
2014-08-01 20:12:15 +03:00
Dmitry Lifshitz
ac77f42d09 env_mmc: add mmc_get_env_addr() prototype
Add missing mmc_get_env_addr() prototype in environment.h

Signed-off-by: Dmitry Lifshitz <lifshitz@compulab.co.il>
Acked-by: Pantelis Antoniou <panto@antoniou-consulting.com>
2014-08-01 20:11:59 +03:00
Marek Vasut
a4223b746d env: Implement support for encrypting environment
Add function which allows encrypting the whole environment block with
AES-128-CBC. The key for the environment is retrieved by
env_aes_cbc_get_key() function, which must be implemented on a per-board
basis.

Signed-off-by: Marek Vasut <marex@denx.de>
2014-03-21 16:44:02 -04:00
Marek Vasut
7ce1526ed2 env: Add env_export() wrapper
Implement env_export() wrapper, so that all implementers of saveenv() don't
have to call hexport_r(), crc32() etc. sequence . This trims down a bit of
code duplication.

Signed-off-by: Marek Vasut <marex@denx.de>
2014-03-21 16:43:59 -04:00
Wolfgang Denk
1a4596601f Add GPL-2.0+ SPDX-License-Identifier to source files
Signed-off-by: Wolfgang Denk <wd@denx.de>
[trini: Fixup common/cmd_io.c]
Signed-off-by: Tom Rini <trini@ti.com>
2013-07-24 09:44:38 -04:00
Bo Shen
5707df7796 mmc: fix env in mmc with redundant compile error
The commit d196bd8 (env_mmc: add support for redundant environment)
introduce the following compile error when enable redundant
environment support with MMC
---8<---
env_mmc.c:149: error: 'env_t' has no member named 'flags'
env_mmc.c:248: error: 'env_t' has no member named 'flags'
env_mmc.c:248: error: 'env_t' has no member named 'flags'
env_mmc.c:250: error: 'env_t' has no member named 'flags'
env_mmc.c:250: error: 'env_t' has no member named 'flags'
env_mmc.c:252: error: 'env_t' has no member named 'flags'
env_mmc.c:252: error: 'env_t' has no member named 'flags'
env_mmc.c:254: error: 'env_t' has no member named 'flags'
env_mmc.c:254: error: 'env_t' has no member named 'flags'
env_mmc.c:267: error: 'env_t' has no member named 'flags'
make[1]: *** [env_mmc.o] Error 1
--->8---

Add this patch to fix it

Signed-off-by: Bo Shen <voice.shen@atmel.com>
Reviewed-by: Michael Heimpold <mhei@heimpold.de>
Signed-off-by: Andy Fleming <afleming@freescale.com>
2013-06-13 16:44:49 -05:00
Joe Hershberger
785881f775 env: Add redundant env support to UBI env
Allow the user to specify two UBI volumes to use for the environment

Signed-off-by: Joe Hershberger <joe.hershberger@ni.com>
2013-04-11 15:52:55 -04:00
Joe Hershberger
2b74433f36 env: Add support for UBI environment
UBI is a better place for the environment on NAND devices because it
handles wear-leveling and bad blocks.

Gluebi is needed in Linux to access the env as an MTD partition.

Signed-off-by: Joe Hershberger <joe.hershberger@ni.com>
2013-04-11 15:52:55 -04:00
Joe Hershberger
267541f776 env: Add support for access control to .flags
Add support for read-only, write-once, and change-default.

Signed-off-by: Joe Hershberger <joe.hershberger@ni.com>
2012-12-13 11:46:56 -07:00
Joe Hershberger
2598090b7e env: Add environment variable flags
Currently just validates variable types as decimal, hexidecimal,
boolean, ip address, and mac address.

If the entry is not found in the env ".flags", then look in the static
one. This allows the env to override the static definitions, but prevents
the need to have every definition in the environment distracting you.

Signed-off-by: Joe Hershberger <joe.hershberger@ni.com>
2012-12-13 11:46:56 -07:00
Joe Hershberger
170ab11075 env: Add support for callbacks to environment vars
Add support for per-variable callbacks to the "hashtable" functions.

Signed-off-by: Joe Hershberger <joe.hershberger@ni.com>

!!!fix comment in callback
2012-12-13 11:46:55 -07:00
Joe Hershberger
7afcf3a55b env: Refactor apply into change_ok
Move the read of the old value to inside the check function.  In some
cases it can be avoided all together and at the least the code is only
called from one place.

Also name the function and the callback to more clearly describe what
it does.

Pass the ENTRY instead of just the name for direct access to the whole
data structure.

Pass an enum to the callback that specifies the operation being approved.

Signed-off-by: Joe Hershberger <joe.hershberger@ni.com>
2012-12-13 11:46:55 -07:00
Gerlando Falauto
b64b7c3df7 env: make "env default" selective, check and apply
Change the syntax (user API) for "env default":
  -f: override write-once variables
  var... : accept individual variable(s)
  -a: all (resetting the whole env is NOT the default behavior)

Enable variable checking and make changes effective by
enabling do_apply argument to himport_r().

Signed-off-by: Gerlando Falauto <gerlando.falauto@keymile.com>
2012-09-18 12:01:52 -07:00
Gerlando Falauto
c5983592e9 env: add check/apply logic to himport_r()
Change hashtable so that a callback function will decide whether a
variable can be overwritten, and possibly apply the changes.

So add a new field to struct hsearch_data:

 o "apply" callback function to check whether a variable can be
    overwritten, and possibly immediately apply the changes;
    when NULL, no check is performed.

And a new argument to himport_r():
 o "do_apply": whether to call the apply callback function

NOTE: This patch does not change the current behavior.

Signed-off-by: Gerlando Falauto <gerlando.falauto@keymile.com>
Reviewed-by: Marek Vasut <marex@denx.de>
2012-09-18 12:01:52 -07:00
Marek Vasut
b37d41aa24 Block: Remove MG DISK support
This driver is unused and obsolete.

Signed-off-by: Marek Vasut <marex@denx.de>
Cc: Wolfgang Denk <wd@denx.de>
Cc: unsik Kim <donari75@gmail.com>
2012-06-21 20:53:09 +02:00
Igor Grinberg
6f403bad80 env: remove value from boolean defines
Several boolean defines have a value assigned.
Remove the value as defining the symbol is enough.

Signed-off-by: Igor Grinberg <grinberg@compulab.co.il>
Acked-by: Marek Vasut <marek.vasut@gmail.com>
Acked-by: Mike Frysinger <vapier@gentoo.org>
2012-01-05 16:35:54 +01:00
Igor Grinberg
27aafe988e env: clean env_common.c checkpatch and code style
Cleanup the env_common.c checkpatch warnings, errors and coding style.

Signed-off-by: Igor Grinberg <grinberg@compulab.co.il>
2011-11-22 08:39:27 +01:00
Igor Grinberg
d09b1787a4 env: clean cmd_nvedit.c checkpatch and code style
Cleanup the cmd_nvedit.c checkpatch warnings, errors and coding style.
There are 10 wanrings left about the simple_strtoul() function:
 WARNING: simple_strtoul is obsolete, use kstrtoul instead
 #359: FILE: cmd_nvedit.c:359:
 +		load_addr = simple_strtoul(argv[2], NULL, 16);

 ...

 total: 0 errors, 10 warnings, 1043 lines checked

Signed-off-by: Igor Grinberg <grinberg@compulab.co.il>
2011-11-22 08:39:25 +01:00
Igor Grinberg
994bc671cf env: move extern environment[] to environment.h
Extract all extern declarations for environment out of c files
into the environment.h header.

Signed-off-by: Igor Grinberg <grinberg@compulab.co.il>
2011-11-22 08:39:25 +01:00
Igor Grinberg
d1459f0fab env: move extern default_environment[] to environment.h
Extract all extern declarations for default_environment[] out of c files
into the environment.h header.

Signed-off-by: Igor Grinberg <grinberg@compulab.co.il>
Cc: Stefan Roese <sr@denx.de>
Acked-by: Stefan Roese <sr@denx.de>
2011-11-22 08:39:25 +01:00
Igor Grinberg
507651d611 env: clean environment.h checkpatch and code style
Though one warning left:
 WARNING: do not add new typedefs
 #149: FILE: u-boot/include/environment.h:149:
 +typedef struct environment_s {

 total: 0 errors, 1 warnings, 181 lines checked

Signed-off-by: Igor Grinberg <grinberg@compulab.co.il>
2011-11-22 08:39:25 +01:00
Wolfgang Denk
33a6b9e90b environment.h: fix warning: "CONFIG_ENV_IS_EMBEDDED" redefined
Signed-off-by: Wolfgang Denk <wd@denx.de>
Cc: Stefan Roese <sr@denx.de>
2011-08-01 15:20:16 +02:00
Mike Frysinger
147c7169e8 constify default env
I can't see any obvious needs for the default environment to be writable,
so make it const.

Signed-off-by: Mike Frysinger <vapier@gentoo.org>
2011-07-26 16:34:22 +02:00
Yoshihiro Shimoda
efb063390d add checking the CONFIG_ENV_IS_IN_SPI_FLASH in Enbedded env
Fix the problem which cannot build the U-boot, if we only set
the CONFIG_ENV_IS_IN_SPI_FLASH.

Signed-off-by: Yoshihiro Shimoda <yoshihiro.shimoda.uh@renesas.com>
Acked-by: Nobuhiro Iwamatsu <iwamatsu@nigauri.org>
2011-02-15 22:09:50 +01:00
Mike Frysinger
2eb1573f01 hashtable: drop all non-reentrant versions
The non-reentrant versions of the hashtable functions operate on a single
shared hashtable.  So if two different people try using these funcs for
two different purposes, they'll cause problems for the other.

Avoid this by converting all existing hashtable consumers over to the
reentrant versions and then punting the non-reentrant ones.

Signed-off-by: Mike Frysinger <vapier@gentoo.org>
2010-12-17 21:07:14 +01:00
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