[coreboot-gerrit] Patch merged into coreboot/master: libpayload: cbfs: Add cbfs_handle API for more fine-grained accesses

[gerrit at coreboot.org]

the following patch was just integrated into master:
commit 2296479dfd886d4cf4c145f1d3ed1ec64dc20630
Author: Julius Werner <jwerner at chromium.org>
Date:   Thu May 12 14:40:57 2016 -0700

    libpayload: cbfs: Add cbfs_handle API for more fine-grained accesses
    
    The libpayload CBFS APIs are pretty old and clunky, primarily because of
    the way the cbfs_media struct may or may not be passed in and may be
    initialized inside the API calls in a way that cannot be passed back out
    again. Due to this, the only real CBFS access function we have always
    reads a whole file with all metadata, and everything else has to build
    on top of that. This makes certain tasks like reading just a file
    attribute very inefficient on non-memory-mapped platforms (because you
    always have to map the whole file).
    
    This patch isn't going to fix the world, but will allow a bit more
    flexibility by bolting a new API on top which uses a struct cbfs_handle
    to represent a found but not yet read file. A cbfs_handle contains a
    copy of the cbfs_media needed to read the file, so it can be kept and
    passed around to read individual parts of it after the initial lookup.
    The existing (non-media) legacy API is retained for backwards
    compatibility, as is cbfs_file_get_contents() (which is most likely what
    more recent payloads would have used, and also a good convenience
    wrapper for the most simple use case), but they are now implemented on
    top of the new API.
    
    TEST=Booted Oak, made sure that firmware screens and software sync
    worked okay.
    
    Change-Id: I269f3979e77ae691ee9d4e1ab564eff6d45b7cbe
    Signed-off-by: Julius Werner <jwerner at chromium.org>
    Reviewed-on: https://review.coreboot.org/14810
    Tested-by: build bot (Jenkins)
    Reviewed-by: Aaron Durbin <adurbin at chromium.org>


See https://review.coreboot.org/14810 for details.

-gerrit