[i-g-t PATCH 5/6] intel_bios_reader: port the sequence block parsing from kernel

Jani Nikula
2016-01-14T15:51:43Z

Reuse the same code as kernel. Also parses v3, although does not
actually dump that stuff yet.

Signed-off-by: Jani Nikula <jani.nikula@intel.com>
---
tools/intel_bios_reader.c | 141 +++++++++++++++++++++++++++++++++++++++++++++-
1 file changed, 140 insertions(+), 1 deletion(-)

diff --git a/tools/intel_bios_reader.c b/tools/intel_bios_reader.c
index eb550817c44e..944ad5315f3a 100644
--- a/tools/intel_bios_reader.c
+++ b/tools/intel_bios_reader.c
@@ -1054,12 +1054,120 @@ find_panel_sequence_block(const struct bdb_mipi_sequence *sequence,
return NULL;
}

+static int goto_next_sequence(const uint8_t *data, int index, int total)
+{
+ uint16_t len;
+
+ /* Skip Sequence Byte. */
+ for (index = index + 1; index < total; index += len) {
+ uint8_t operation_byte = *(data + index);
+ index++;
+
+ switch (operation_byte) {
+ case MIPI_SEQ_ELEM_END:
+ return index;
+ case MIPI_SEQ_ELEM_SEND_PKT:
+ if (index + 4 > total)
+ return 0;
+
+ len = *((const uint16_t *)(data + index + 2)) + 4;
+ break;
+ case MIPI_SEQ_ELEM_DELAY:
+ len = 4;
+ break;
+ case MIPI_SEQ_ELEM_GPIO:
+ len = 2;
+ break;
+ case MIPI_SEQ_ELEM_I2C:
+ if (index + 7 > total)
+ return 0;
+ len = *(data + index + 6) + 7;
+ break;
+ default:
+ fprintf(stderr, "Unknown operation byte\n");
+ return 0;
+ }
+ }
+
+ return 0;
+}
+
+static int goto_next_sequence_v3(const uint8_t *data, int index, int total)
+{
+ int seq_end;
+ uint16_t len;
+ uint32_t size_of_sequence;
+
+ /*
+ * Could skip sequence based on Size of Sequence alone, but also do some
+ * checking on the structure.
+ */
+ if (total < 5) {
+ fprintf(stderr, "Too small sequence size\n");
+ return 0;
+ }
+
+ /* Skip Sequence Byte. */
+ index++;
+
+ /*
+ * Size of Sequence. Excludes the Sequence Byte and the size itself,
+ * includes MIPI_SEQ_ELEM_END byte, excludes the final MIPI_SEQ_END
+ * byte.
+ */
+ size_of_sequence = *((const uint32_t *)(data + index));
+ index += 4;
+
+ seq_end = index + size_of_sequence;
+ if (seq_end > total) {
+ fprintf(stderr, "Invalid sequence size\n");
+ return 0;
+ }
+
+ for (; index < total; index += len) {
+ uint8_t operation_byte = *(data + index);
+ index++;
+
+ if (operation_byte == MIPI_SEQ_ELEM_END) {
+ if (index != seq_end) {
+ fprintf(stderr, "Invalid element structure\n");
+ return 0;
+ }
+ return index;
+ }
+
+ len = *(data + index);
+ index++;
+
+ /*
+ * FIXME: Would be nice to check elements like for v1/v2 in
+ * goto_next_sequence() above.
+ */
+ switch (operation_byte) {
+ case MIPI_SEQ_ELEM_SEND_PKT:
+ case MIPI_SEQ_ELEM_DELAY:
+ case MIPI_SEQ_ELEM_GPIO:
+ case MIPI_SEQ_ELEM_I2C:
+ case MIPI_SEQ_ELEM_SPI:
+ case MIPI_SEQ_ELEM_PMIC:
+ break;
+ default:
+ fprintf(stderr, "Unknown operation byte %u\n",
+ operation_byte);
+ break;
+ }
+ }
+
+ return 0;
+}
+
static void dump_mipi_sequence(const struct bdb_header *bdb,
const struct bdb_block *block)
{
const struct bdb_mipi_sequence *sequence = block->data;
const uint8_t *data;
uint32_t seq_size;
+ int index = 0;

/* Check if we have sequence block as well */
if (!sequence) {
@@ -1069,14 +1177,45 @@ static void dump_mipi_sequence(const struct bdb_header *bdb,

printf("\tSequence block version v%u\n", sequence->version);

- if (sequence->version >= 3)
+ /* Fail gracefully for forward incompatible sequence block. */
+ if (sequence->version >= 4) {
+ fprintf(stderr, "Unable to parse MIPI Sequence Block v%u\n",
+ sequence->version);
return;
+ }

data = find_panel_sequence_block(sequence, panel_type,
block->size, &seq_size);
if (!data)
return;

+ /* Parse the sequences. Corresponds to VBT parsing in the kernel. */
+ for (;;) {
+ uint8_t seq_id = *(data + index);
+ if (seq_id == MIPI_SEQ_END)
+ break;
+
+ if (seq_id >= MIPI_SEQ_MAX) {
+ fprintf(stderr, "Unknown sequence %u\n", seq_id);
+ return;
+ }
+
+ if (sequence->version >= 3)
+ index = goto_next_sequence_v3(data, index, seq_size);
+ else
+ index = goto_next_sequence(data, index, seq_size);
+ if (!index) {
+ fprintf(stderr, "Invalid sequence %u\n", seq_id);
+ return;
+ }
+ }
+
+ if (sequence->version >= 3) {
+ fprintf(stderr, "Unable to dump MIPI Sequence Block v%u\n",
+ sequence->version);
+ return;
+ }
+
/*
* loop into the sequence data and split into multiple sequneces
* There are only 5 types of sequences as of now