This function is a relic from the past when environment was read from
underlying device one character at a time.

It is used only in the case when getting an environemnt variable prior
relocation, and the function is simple enough to be inlined there.

Since env_get_char() is being changed to simple access to an array, we
can drop the failing cases and simplify the code (this could have been
done before, since env_get_char() did not fail even before).

Signed-off-by: Marek Behún <marek.behun@nic.cz>
Reviewed-by: Simon Glass <sjg@chromium.org>

Commit b2cdef4861be ("env: restore old env_get_char() behaviour")
dropped the .get_char() method from struct env_driver, but left the two
existing implementations (eeprom and nvram) in case someone would use
them by overwriting weak function env_get_char_spec().

Since this was never done in the 3.5 years, let's drop these methods and
simplify the code.

Signed-off-by: Marek Behún <marek.behun@nic.cz>
Reviewed-by: Simon Glass <sjg@chromium.org>

This fixes the case where there are multiple environment drivers, one of
them is the default environment one, and it is followed by an environment
driver which does not implement .init() callback. The default environment
driver sets gd->env_valid to ENV_INVALID and returns 0 from its .init()
callback implementation, which is valid behavior for default environment.

Since the subsequent environment driver does not implement .init(), it
also does not modify the $ret variable in the loop. Therefore, the loop
is exited with gd->env_valid=ENV_INVALID and ret=0, which means that the
code further down in env_init() will not reset the environment to the
default one, which is incorrect.

This patch sets the $ret variable back to -ENOENT in case the env_valid
is set to ENV_INVALID by an environment driver, so that the environment
would be correctly reset back to default one, unless a subsequent driver
loads a valid environment.

Signed-off-by: Marek Vasut <marex@denx.de>
Tested-By: Tim Harvey <tharvey@gateworks.com>

Move this out of the common header and include it only where needed.  In
a number of cases this requires adding "struct udevice;" to avoid adding
another large header or in other cases replacing / adding missing header
files that had been pulled in, very indirectly.   Finally, we have a few
cases where we did not need to include <asm/global_data.h> at all, so
remove that include.

Signed-off-by: Simon Glass <sjg@chromium.org>
Signed-off-by: Tom Rini <trini@konsulko.com>

Michael wrote:
commit 92765f45bb95 ("env: Access Environment in SPI flashes before
relocation") at least breaks the Kontron sl28 board. I guess it also
breaks others which use a (late) SPI environment.

reason is, that env_init() sets the init bit, if there
is no init function defined in an environment driver,
and use default return value -ENOENT in this case
later for setting the default environment.

Change:
Environment driver can now implement an init
function and return, if this function does nothing,
simply -ENOENT.

env_init() now handles -ENOENT correct by setting the
inited bit for the environment driver. And if there
is no other environment driver whose init function
returns 0, load than the default environment.

This prevents that each environment driver needs to set the
default environment.

Fixes: 92765f45bb95 ("env: Access Environment in SPI flashes before relocation")
Reported-by: Michael Walle <michael@walle.cc>
Tested-by: Michael Walle <michael@walle.cc> [For the SF environment]
Signed-off-by: Heiko Schocher <hs@denx.de>

Add configuration option which prevents the environment hash table to be
ever cleared and reloaded with different content. This is useful in case
the first environment loaded into the hash table contains e.g. sensitive
content which must not be dropped or reloaded.

Signed-off-by: Marek Vasut <marex@denx.de>
Reviewed-by: Tom Rini <trini@konsulko.com>

Add the new command 'env select' to force the persistent storage
of environment, saved in gd->env_load_prio.

Signed-off-by: Patrick Delaunay <patrick.delaunay@st.com>

Add the new command env load to load the environment from
the current location gd->env_load_prio.

Signed-off-by: Patrick Delaunay <patrick.delaunay@st.com>

The ops driver load becomes mandatory in struct env_drive,
change the comment for this ops and remove unnecessary test.

Signed-off-by: Patrick Delaunay <patrick.delaunay@st.com>

Only update gd->env_load_prio in generic function env_load()
and no more in the weak function env_get_location() which is
called in many place (for example in env_driver_lookup, even
for ENVOP_SAVE operation).

This patch is a preliminary step to use env_driver_lookup()/
env_get_location() in new function env_select() without
updating gd->env_load_prio.

Signed-off-by: Patrick Delaunay <patrick.delaunay@st.com>