Some environment variables affect the operation of bootm. Reading these
variables is buried within the boot code at present.
Ideally this information should be in struct bootm_info so that it can
be provided directly, without needing the environment variables. Also it
should support allocation if the variables are not provided.
As a first step towards this, add an explicit read of the variables,
storing the values. For now this only covers kernel_comp_addr_r and
kernel_comp_size
Signed-off-by: Simon Glass <sjg@chromium.org>
7618b665a7