[U-Boot] [PATCH v3 0/6] env: handle special variables and selective env default

[Gerlando Falauto]

This patchset modifies the handling of all the operations on the environment
(set/import/default) so to unify handling of special variables.
On top of that we implement a selective "env default".

A selective "env import" would imply a user API change and should therefore
be discussed separately.

NOTE:
The entire patchset generates an increase in code size of about 1200 bytes
on a PowerPC target. 
As much as I would like to get rid of the set_default_vars() function in 
env_common.c, I have not found a nice way to do so.

Changes in the syntax (user API):
- "env default" -f: override write-once variables, -a means all
- display a warning when trying to set to default variables not
  present in the default env.

Changes from v2:
- removed typedef for callback, moved to the hashtable (struct hsearch_data)
- refactored patchset into smaller patches
  (only patch 5 and 6 should have any visible effect)
- added handling of selected variables not present in the imported env
- removed CONFIG_CMD_DEFAULTENV_VARS
- cosmetic formatting

Changes from v1:
- removed cosmetic patches (now mainstream)
- rebased to latest trunk
- removed subtle error in env_check_apply
  (comparing {loadaddr, bootfile} to values instead
  of variable names)
- changed env_check_apply so not to display warnings
  in case of H_FORCE flag being set

Changes from v0
- checkpatch cleanup
- removed himport_ex()
- removed warning for serial_assign()
- env import NOT implemented here

Gerlando Falauto (6):
  env: unify logic to check and apply changes
  env: make himport_r() selective on variables
  env: add check/apply logic to himport_r()
  env: check and apply changes on delete/destroy
  env: make "env default" selective, check and apply
  env: delete selected vars not present in imported env

 common/cmd_nvedit.c   |  216 +++++++++++++++++++++++++++++++++----------------
 common/env_common.c   |   36 ++++++++-
 include/environment.h |   12 +++
 include/search.h      |   26 +++++-
 lib/hashtable.c       |   95 ++++++++++++++++++++--
 5 files changed, 300 insertions(+), 85 deletions(-)