gsctool: add RO descriptor parser

This patch adds code which would parse the RO hash/dump descriptor
file including a database listing expected values of hashes for
various ranges of target SPI flash devices, or areas which need to be
printed out (hex dumped) for operator inspection.

Lines starting with '#' are completely ignored. The rest of the
logical lines could actually split into multiple text lines in the
file, so to separate one logical line from another at least one empty
line is required.

Hash descriptor database file consists of sections for various Chrome
OS boards. Each board description section starts with a logical line
of 4 characters which is the board ID (the same as the board's RLZ
code).

Each board description section includes variable number of range
descriptor entries, each entry being a logical line, potentially split
into multiple text lines.

Each entry consists of semicolon separated fields:

 {a|e|g}:{h|d}:base_addr:size[:value[:value[:value...]]]]

 Where

  - the first sindgle character field defines the way the range is
    accessed:
     a - AP flash
     e - EC flash
     g - EC flash requiring gang programming mode
  - the second single character field defines the range type
     h - Cr50 returns the hash of the range
     d - Cr50 returns actual contents of the range (hex dump)
   - the third and and forth fields are base address and size of the range
   - ranges of type 'h' include one or more values for the hash of the
     range, each hash is a 64 byte hex string. Ranges of type 'd' do
     not include any data.

All values are expressed in hex.

The parser API provides functions to open the passed in hash
descriptor file and find there the section for a particular board, a
function to advance to the next entry in the board's section, and a
function to close the file when board entries scanning is completed.

When scanning the entries, the parser verifies their sanity, i.e.
conformance with the above described format, that all hashes are of
the right size, that there are no hashes attached to 'dump' entries
and there is at least one hash attached to the 'hash' entries, and
that there are no invalid characters in the hashes and address range
definitions.

The parser is not yet used by the gsctool, but when the new module is
compiled stand alone with -DTEST_PARSER passed to the compiler, it
becomes an executable which can be given the test hash database (the
new file, sample_descriptor) to interpret and report success or
failure.

BRANCH=none
BUG=chromium:812880
TEST=ran the following commands:

  $ gcc -DTEST_PARSER desc_parser.c -o dp
  $ ./dp sample_descriptor
  Section 1, rv 0
  Section 2, rv 0
  Section 3, rv 0
  Unexpected data in section 4
  Section 4, rv -22
  Invalid hash 1 size 0 in section 5
  Section 5, rv -22
  Invalid hash 1 size 0 in section 6
  Section 6, rv -22
  Invalid hash 1 size 63 in section 7
  Section 7, rv -22
  Invalid hash 1 size 65 in section 8
  Section 8, rv -22
  Invalid hash 1 value in section 9
  Section 9, rv -22
  Unexpected number of variants in section 10
  Section 10, rv -22
  Invalid hex value 10x in section 11
  Section 11, rv -22
  Section 12, rv -61
  $

Change-Id: I14b2754a5f6ba26b3c56ddc26d45cb4574514b69
Signed-off-by: Vadim Bendebury <vbendeb@chromium.org>
Reviewed-on: https://chromium-review.googlesource.com/923419
Reviewed-by: Andrey Pronin <apronin@chromium.org>

1 files changed, 5 insertions, 2 deletions

diff --git a/extra/usb_updater/Makefile b/extra/usb_updater/Makefile
index fedb959356..86632903c8 100644
--- a/extra/usb_updater/Makefile
+++ b/extra/usb_updater/Makefile
@@ -41,7 +41,7 @@ LIBS_common  = -lfmap
 
 all: $(PROGRAMS)
 
-GSCTOOL_SOURCES := gsctool.c
+GSCTOOL_SOURCES := gsctool.c desc_parser.c
 GSCTOOL_OBJS := $(patsubst %.c,%.o,$(GSCTOOL_SOURCES))
 DEPS := $(patsubst %.c,%.d,$(GSCTOOL_SOURCES))
 
@@ -59,6 +59,9 @@ usb_updater2: usb_updater2.c Makefile
 .PHONY: clean
 
 clean:
-	rm -rf $(PROGRAMS) *~ *.o *.d
+	rm -rf $(PROGRAMS) *~ *.o *.d dp
+
+parser_debug: desc_parser.c
+	gcc -g -O0  -DTEST_PARSER desc_parser.c -o dp
 
 -include $(DEPS)