Add command-line documentation for binman.

Signed-off-by: Simon Glass <sjg@chromium.org>

These are documented in various several sections. Add a new section that
mentions them all in one place so it is easier to see what environment
variables can be used to control U-Boot's use of binman.

Signed-off-by: Simon Glass <sjg@chromium.org>
Suggested-by: Heinrich Schuchardt <xypron.glpk@gmx.de>

At present binman returns success when told to handle missing/faked blobs
or missing bintools. This is confusing since in fact the resulting image
cannot work.

Use exit code 103 to signal this problem, with a -W option to convert
it to a warning.

Rename the flag to --ignore-missing since it controls bintools also.

Add documentation about exit codes while we are here.

Signed-off-by: Simon Glass <sjg@chromium.org>

This reverts commit daa2da754afe1bac777f6cb0f05233e0de7b325d.

This commit is not needed anymore since the btool_ prefix is
automatically stripped by bintool.

Cc: Quentin Schulz <foss+uboot@0leil.net>
Signed-off-by: Quentin Schulz <quentin.schulz@theobroma-systems.com>
Reviewed-by: Simon Glass <sjg@chromium.org>

The binary is looked on the system by the suffix of the packer class.
This means binman was looking for btool_gzip on the system and not gzip.

Since a btool can have its btool_ prefix missing but its module and
binary presence on the system appropriately found, there's no need to
actually keep this prefix after listing all possible btools, so let's
remove it.

This fixes gzip btool by letting Bintool.find_bintool_class handle the
missing prefix and still return the correct class which is then init
with gzip name instead of btool_gzip.

Additionally, there was an issue with the cached module global variable.
The variable only stores the module and not the associated class name
when calling find_bintool_class.
This means that when caching the module on the first call to
find_bintool_class, class_name would be set to Bintoolbtool_gzip but the
module_name gzip only, adding the module in the gzip key in the module
dictionary. When hitting the cache on next calls, the gzip key would be
found, so its value (the module) is used. However the default class_name
(Bintoolgzip) is used, failing the getattr call.

Instead, let's enforce the same class name: Bintool<packer>, whatever
the filename it is contained in.

Cc: Quentin Schulz <foss+uboot@0leil.net>
Signed-off-by: Quentin Schulz <quentin.schulz@theobroma-systems.com>
Reviewed-by: Simon Glass <sjg@chromium.org>

In some cases the ELF version of SPL builds may be packaged, rather
than a binary .bin file. Add support for this.

Signed-off-by: Simon Glass <sjg@chromium.org>

This feature is used by several etypes and we plan to add more that use
it. Make symbol writing a feature of the base class to reduce the code
duplication.

Signed-off-by: Simon Glass <sjg@chromium.org>

Move this code into its own function so it can be used from tests.

Signed-off-by: Simon Glass <sjg@chromium.org>

Provide a function to obtain the integer value of an ELF symbol. This will
be used

Signed-off-by: Simon Glass <sjg@chromium.org>

The current name is inconsistent with SPL which uses CONFIG_SPL_TEXT_BASE
and this makes it imposible to use CONFIG_VAL().

Rename it to resolve this problem.

Signed-off-by: Simon Glass <sjg@chromium.org>