Utility to dump boot timing table

Coreboot and u-boot create a table of timestamps which allows to see
the boot process performance. The util/cbmem/cbmem.py script allows to
access the table after ChromeOS boots up and display its contents on
the console. The problem is that shipping images do not include Python
interpreter, so there is no way to access the table on a production
machine.

This change introduces a utility which is a Linux app displaying the
timestamp table. Conceivably the output of this utility might be
included in one of the ChromeOS :/system sections, so it was attempted
to write this procedure 'fail safe', namely reporting errors and not
continuing processing if something goes wrong.

Including of coreboot/src .h files will allow to keep the firmware
timestamp implementation and this utility in sync in the future.

Test:
    . build the utility (run 'make' while in chroot in  util/cbmem)
    . copy `cbmem' and 'cbmem.py' to the target
    . run both utilities (limiting cbmem.py output to 25 lines or so)
    . observe that the generated tables are identical (modulo rounding
      up of int division, resulting in 1 ns discrepancies in some
      cases)

      localhost var # ./cbmem
      18 entries total:

         1:62,080
         2:64,569 (2,489)
         3:82,520 (17,951)
         4:82,695 (174)
         8:84,384 (1,688)
         9:131,731 (47,347)
        10:131,821 (89)
        30:131,849 (27)
        40:132,618 (769)
        50:134,594 (1,975)
        60:134,729 (134)
        70:363,440 (228,710)
        75:363,453 (13)
        80:368,165 (4,711)
        90:370,018 (1,852)
        99:488,217 (118,199)
      1000:491,324 (3,107)
      1100:760,475 (269,150)

      localhost var # ./cbmem.py | head -25

      time base 4249800, total entries 18
      1:62,080
      2:64,569  (2,489)
      3:82,520  (17,951)
      4:82,695  (174)
      8:84,384  (1,688)
      9:131,731  (47,347)
      10:131,821  (89)
      30:131,849  (27)
      40:132,618  (769)
      50:134,594  (1,975)
      60:134,729  (134)
      70:363,440  (228,710)
      75:363,453  (13)
      80:368,165  (4,711)
      90:370,018  (1,852)
      99:488,217  (118,199)
      1000:491,324  (3,107)
      1100:760,475  (269,150)

Change-Id: I013e594d4afe323106d88e7938dd40b17760621c
Signed-off-by: Vadim Bendebury <vbendeb@chromium.org>
Reviewed-on: http://review.coreboot.org/1759
Tested-by: build bot (Jenkins)
Reviewed-by: Stefan Reinauer <stefan.reinauer@coreboot.org>

0 files changed, 0 insertions, 0 deletions