[U-Boot] [PATCH v2] dfu: Introduction of the "dfu_checksum_method" env variable for checksum method setting

Lukasz Majewski
2014-05-05T13:16:26Z

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>
Cc: Marek Vasut <marex@denx.de>
---
Dependency:
"lib:crc32: Allow setting of the initial crc32 value"
http://patchwork.ozlabs.org/patch/345720/

Changes for v2:
- Utilization of hash_block generic function to calculate CRC32 checksum

---
drivers/dfu/dfu.c | 53 +++++++++++++++++++++++++++++++++++++++++++++++------
1 file changed, 47 insertions(+), 6 deletions(-)

diff --git a/drivers/dfu/dfu.c b/drivers/dfu/dfu.c
index 51b1026..7705c37 100644
--- a/drivers/dfu/dfu.c
+++ b/drivers/dfu/dfu.c
@@ -13,6 +13,7 @@
#include <mmc.h>
#include <fat.h>
#include <dfu.h>
+#include <hash.h>
#include <linux/list.h>
#include <linux/compiler.h>

@@ -20,6 +21,7 @@ static bool dfu_reset_request;
static LIST_HEAD(dfu_list);
static int dfu_alt_num;
static int alt_num_cnt;
+static char *dfu_checksum_method;

bool dfu_reset(void)
{
@@ -99,6 +101,24 @@ unsigned char *dfu_get_buf(void)
return dfu_buf;
}

+static char *dfu_get_checksum_method(void)
+{
+ char *s;
+
+ s = getenv("dfu_checksum_method");
+ if (!s)
+ return NULL;
+
+ if (!strcmp(s, "crc32")) {
+ debug("%s: DFU checksum method: %s\n", __func__, s);
+ return s;
+ }
+
+ error("DFU checksum method: %s not supported!\n", s);
+
+ return NULL;
+}
+
static int dfu_write_buffer_drain(struct dfu_entity *dfu)
{
long w_size;
@@ -109,9 +129,16 @@ 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) {
+ hash_block(dfu_checksum_method, dfu->i_buf_start, w_size,
+ (uint8_t *)&dfu->crc, NULL);
+ /*
+ * Call to ntohl() is necessary because of
+ * hash_block() implementation, which returns
+ * crc32 in the network order (big endian)
+ */
+ dfu->crc = ntohl(dfu->crc);
+ }
ret = dfu->write_medium(dfu, dfu->offset, dfu->i_buf_start, &w_size);
if (ret)
debug("%s: Write error!\n", __func__);
@@ -134,7 +161,9 @@ int dfu_flush(struct dfu_entity *dfu, void *buf, int size, int blk_seq_num)
if (dfu->flush_medium)
ret = dfu->flush_medium(dfu);

- printf("\nDFU complete CRC32: 0x%08x\n", dfu->crc);
+ if (dfu_checksum_method)
+ printf("\nDFU complete %s: 0x%08x\n", dfu_checksum_method,
+ dfu->crc);

/* clear everything */
dfu_free_buf();
@@ -234,7 +263,16 @@ 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) {
+ hash_block(dfu_checksum_method, buf, chunk,
+ (uint8_t *)&dfu->crc, NULL);
+ /*
+ * Call to ntohl() is necessary because of
+ * hash_block() implementation, which returns
+ * crc32 in the network order (big endian)
+ */
+ dfu->crc = ntohl(dfu->crc);
+ }
dfu->i_buf += chunk;
dfu->b_left -= chunk;
dfu->r_left -= chunk;
@@ -318,7 +356,9 @@ 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)
+ debug("%s: %s %s: 0x%x\n", __func__, dfu->name,
+ dfu_checksum_method, dfu->crc);
puts("\nUPLOAD ... done\nCtrl+C to exit ...\n");

dfu_free_buf();
@@ -393,6 +433,7 @@ 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);

+ dfu_checksum_method = dfu_get_checksum_method();
dfu = calloc(sizeof(*dfu), dfu_alt_num);
if (!dfu)
return -1;
--
1.7.10.4