Am 03.03.2013 23:57 schrieb Stefan Tauner:
> Signed-off-by: Stefan Tauner <[email protected]>
> ---
> flash.h | 2 ++
> flashrom.c | 38 +++++++++++++++++++++++---------------
> 2 files changed, 25 insertions(+), 15 deletions(-)
>
> diff --git a/flash.h b/flash.h
> index 7dd9d9f..1df43c4 100644
> --- a/flash.h
> +++ b/flash.h
> @@ -66,11 +66,13 @@ enum chipbustype {
> * - 128 bytes: If less than 128 bytes are written, the rest will be erased.
> Each write to a 128-byte region
> * will trigger an automatic erase before anything is written. Very
> uncommon behaviour.
> * - 256 bytes: If less than 256 bytes are written, the contents of the
> unwritten bytes are undefined.
> + * - 264 bytes: FIXME
Just copy the comment from 256 bytes. If that isn't completely correct,
maybe this would fit:
"If less than 264 bytes are written, the contents of all bytes of the
write operation are undefined." AFAICS my text is inaccurate for
Dataflash, though.
> */
> enum write_granularity {
> write_gran_256bytes = 0, /* We assume 256 byte granularity on default.
> */
> write_gran_1bit,
> write_gran_1byte,
> + write_gran_264bytes,
Should we reverse the order of the values in that enum to have an
ordering by size?
> };
>
> /*
> diff --git a/flashrom.c b/flashrom.c
> index 225b6f0..fc5e34a 100644
> --- a/flashrom.c
> +++ b/flashrom.c
> @@ -676,6 +676,21 @@ out_free:
> return ret;
> }
>
> +static int need_erase_n_byte(uint8_t *have, uint8_t *want, unsigned int len,
> unsigned int n)
Different name for the function maybe? Not sure, it doesn't sound too bad.
> +{
> + unsigned int i, j, limit;
> + for (j = 0; j < len / n; j++) {
> + limit = min (n, len - j * n);
> + /* Are 'have' and 'want' identical? */
> + if (!memcmp(have + j * n, want + j * n, limit))
> + continue;
> + /* have needs to be in erased state. */
> + for (i = 0; i < limit; i++)
> + if (have[j * n + i] != 0xff)
> + return 1;
> + }
> + return 0;
> +}
> /*
> * Check if the buffer @have can be programmed to the content of @want
> without
> * erasing. This is only possible if all chunks of size @gran are either kept
> @@ -693,7 +708,7 @@ out_free:
> int need_erase(uint8_t *have, uint8_t *want, unsigned int len, enum
> write_granularity gran)
> {
> int result = 0;
> - unsigned int i, j, limit;
> + unsigned int i;
>
> switch (gran) {
> case write_gran_1bit:
> @@ -711,20 +726,10 @@ int need_erase(uint8_t *have, uint8_t *want, unsigned
> int len, enum write_granul
> }
> break;
> case write_gran_256bytes:
> - for (j = 0; j < len / 256; j++) {
> - limit = min (256, len - j * 256);
> - /* Are 'have' and 'want' identical? */
> - if (!memcmp(have + j * 256, want + j * 256, limit))
> - continue;
> - /* have needs to be in erased state. */
> - for (i = 0; i < limit; i++)
> - if (have[j * 256 + i] != 0xff) {
> - result = 1;
> - break;
> - }
> - if (result)
> - break;
> - }
> + result = need_erase_n_byte(have, want, len, 256);
> + break;
> + case write_gran_264bytes:
> + result = need_erase_n_byte(have, want, len, 264);
The refactoring of that code is a really good idea.
> break;
> default:
> msg_cerr("%s: Unsupported granularity! Please report a bug at "
> @@ -772,6 +777,9 @@ static unsigned int get_next_write(uint8_t *have, uint8_t
> *want, unsigned int le
> case write_gran_256bytes:
> stride = 256;
> break;
> + case write_gran_264bytes:
> + stride = 264;
> + break;
> default:
> msg_cerr("%s: Unsupported granularity! Please report a bug at "
> "[email protected]\n", __func__);
Overall, I like it.
Regards,
Carl-Daniel
--
http://www.hailfinger.org/
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