[U-Boot] [PATCH 3/3] dfu: Introduction of the "dfu_checksum_method" env variable for checksum method setting

Lukasz Majewski
2014-03-31T08:48:49Z

Up till now the CRC32 of received data was calculated unconditionally.
The standard crc32 implementation causes long delays when large images
were uploaded.

The "dfu_checksum_method" environment variable gives the opportunity to
enable on demand (when e.g. debugging) the crc32 calculation.
It can be done without need to recompile the u-boot binary.

By default the crc32 is not calculated.

Tests results:
400 MiB ums.img file
With crc32 calculation: 65 sec [avg 6.29 MB/s]
Without crc32 calculation: 25 sec [avg 16.17 MB/s]

Signed-off-by: Lukasz Majewski <l.majewski@samsung.com>
---
drivers/dfu/dfu.c | 34 ++++++++++++++++++++++++++++++----
include/dfu.h | 5 +++++
2 files changed, 35 insertions(+), 4 deletions(-)

diff --git a/drivers/dfu/dfu.c b/drivers/dfu/dfu.c
index e15f959..5d50b47 100644
--- a/drivers/dfu/dfu.c
+++ b/drivers/dfu/dfu.c
@@ -20,6 +20,7 @@ static bool dfu_reset_request;
static LIST_HEAD(dfu_list);
static int dfu_alt_num;
static int alt_num_count;
+static int dfu_checksum_method;

bool dfu_reset(void)
{
@@ -99,6 +100,23 @@ unsigned char *dfu_get_buf(void)
return dfu_buf;
}

+static int dfu_get_checksum_method(void)
+{
+ char *s;
+
+ s = getenv("dfu_checksum_method");
+ if (!s)
+ return DFU_NO_CHECKSUM;
+
+ if (!strcmp(s, "crc32")) {
+ debug("%s: DFU checksum method: %s\n", __func__, s);
+ return DFU_CRC32;
+ } else {
+ error("DFU checksum method: %s not supported!\n", s);
+ return -EINVAL;
+ }
+}
+
static int dfu_write_buffer_drain(struct dfu_entity *dfu)
{
long w_size;
@@ -109,8 +127,8 @@ static int dfu_write_buffer_drain(struct dfu_entity *dfu)
if (w_size == 0)
return 0;

- /* update CRC32 */
- dfu->crc = crc32(dfu->crc, dfu->i_buf_start, w_size);
+ if (dfu_checksum_method == DFU_CRC32)
+ dfu->crc = crc32(dfu->crc, dfu->i_buf_start, w_size);

ret = dfu->write_medium(dfu, dfu->offset, dfu->i_buf_start, &w_size);
if (ret)
@@ -234,7 +252,8 @@ static int dfu_read_buffer_fill(struct dfu_entity *dfu, void *buf, int size)
/* consume */
if (chunk > 0) {
memcpy(buf, dfu->i_buf, chunk);
- dfu->crc = crc32(dfu->crc, buf, chunk);
+ if (dfu_checksum_method == DFU_CRC32)
+ dfu->crc = crc32(dfu->crc, buf, chunk);
dfu->i_buf += chunk;
dfu->b_left -= chunk;
dfu->r_left -= chunk;
@@ -318,7 +337,9 @@ int dfu_read(struct dfu_entity *dfu, void *buf, int size, int blk_seq_num)
}

if (ret < size) {
- debug("%s: %s CRC32: 0x%x\n", __func__, dfu->name, dfu->crc);
+ if (dfu_checksum_method == DFU_CRC32)
+ debug("%s: %s CRC32: 0x%x\n", __func__, dfu->name,
+ dfu->crc);
puts("\nUPLOAD ... done\nCtrl+C to exit ...\n");

dfu_free_buf();
@@ -393,6 +414,11 @@ int dfu_config_entities(char *env, char *interface, int num)
dfu_alt_num = dfu_find_alt_num(env);
debug("%s: dfu_alt_num=%d\n", __func__, dfu_alt_num);

+ ret = dfu_get_checksum_method();
+ if (ret < 0)
+ return ret;
+ dfu_checksum_method = ret;
+
dfu = calloc(sizeof(*dfu), dfu_alt_num);
if (!dfu)
return -1;
diff --git a/include/dfu.h b/include/dfu.h
index 751f0fd..855d6dc 100644
--- a/include/dfu.h
+++ b/include/dfu.h
@@ -37,6 +37,11 @@ enum dfu_op {
DFU_OP_WRITE,
};

+enum dfu_checksum {
+ DFU_NO_CHECKSUM = 0,
+ DFU_CRC32,
+};
+
#define DFU_NOT_SUPPORTED -1

struct mmc_internal_data {
--
1.7.10.4