Dear Horatiu,
In message 1543678222-15837-1-git-send-email-horatiu.vultur@microchip.com you wrote:
The flash_read function is a wrapper over spi_flash_read, which enables the env to read multiple flash page size from flash until '\0\0' is read or the end of env partition is reached. Instead of reading the entire env size. When it reads '\0\0', it stops reading further the env and assumes that the rest of env is '\0'.
This is an optimization for large environments that contain few bytes of environment variables. In this case it doesn't need to read the entire environment and only few pages.
Signed-off-by: Horatiu Vultur horatiu.vultur@microchip.com
env/sf.c | 54 +++++++++++++++++++++++++++++++++++++++++++----------- 1 file changed, 43 insertions(+), 11 deletions(-)
diff --git a/env/sf.c b/env/sf.c index 2e3c600..e1e1a94 100644 --- a/env/sf.c +++ b/env/sf.c @@ -81,6 +81,39 @@ static int setup_flash_device(void) return 0; }
+static int is_end(char *addr, int size)
That should be
(const char *addr, size_t size)
instead.
+static int flash_read(struct spi_flash *flash, u32 offset, int size, void *buf)
I think this should be
(const struct spi_flash *flash, u32 offset, size_t len, void *buf)
[Yes, for reasons of consistency with spi_flash_read() I would also rename "size" into "len".]
Also I recommend to chose another name for the function instead of "flash_read". At first glance this looks like a generalization over spi_flash_read() which supports other flash types than SPI flash as well - but it does not. Instead, it is a specialized version of spi_flash_read() tailored for environment reading only.
Maybe spi_flash_read_env() would be a more reasonable name?
+static int flash_read(struct spi_flash *flash, u32 offset, int size, void *buf) +{
- u32 addr = 0;
- u32 page_size = flash->page_size;
- memset(buf, 0x0, size);
- for (int i = 0; i < size / page_size; ++i) {
int ret = spi_flash_read(flash, offset, page_size,&((char *)buf)[addr]);if (ret < 0)return ret;if (is_end(&((char *)buf)[addr], page_size))return 0;addr += page_size;offset += page_size;- }
- return 0;
Is this correct? Is the read() function not supposed to return the number of read bytes?
Best regards,
Wolfgang Denk