Author: stefanct Date: Mon Apr 1 21:34:53 2013 New Revision: 1666 URL: http://flashrom.org/trac/flashrom/changeset/1666
Log: Refine granularity handling in preparation of AT45DB series support. This adds a number of new granularitie and refines the handling of n-byte granularities by extracting the respective code into a helper function which reduces the pain of the above significantly. Signed-off-by: Stefan Tauner <[email protected]> Acked-by: Carl-Daniel Hailfinger <[email protected]> Modified: trunk/flash.h trunk/flashrom.c Modified: trunk/flash.h ============================================================================== --- trunk/flash.h Mon Apr 1 02:46:05 2013 (r1665) +++ trunk/flash.h Mon Apr 1 21:34:53 2013 (r1666) @@ -59,18 +59,22 @@ }; /* - * The following write granularities are known: - * - 1 bit: Each bit can be cleared individually. - * - 1 byte: A byte can be written once. Further writes to an already written byte cause its contents to be - * either undefined or to stay unchanged. - * - 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. + * The following enum defines possible write granularities of flash chips. These tend to reflect the properties + * of the actual hardware not necesserily the write function(s) defined by the respective struct flashchip. + * The latter might (and should) be more precisely specified, e.g. they might bail out early if their execution + * would result in undefined chip contents. */ enum write_granularity { - write_gran_256bytes = 0, /* We assume 256 byte granularity by default. */ - write_gran_1bit, - write_gran_1byte, + /* We assume 256 byte granularity by default. */ + write_gran_256bytes = 0,/* If less than 256 bytes are written, the unwritten bytes are undefined. */ + write_gran_1bit, /* Each bit can be cleared individually. */ + write_gran_1byte, /* A byte can be written once. Further writes to an already written byte cause + * its contents to be either undefined or to stay unchanged. */ + write_gran_264bytes, /* If less than 264 bytes are written, the unwritten bytes are undefined. */ + write_gran_512bytes, /* If less than 512 bytes are written, the unwritten bytes are undefined. */ + write_gran_528bytes, /* If less than 528 bytes are written, the unwritten bytes are undefined. */ + write_gran_1024bytes, /* If less than 1024 bytes are written, the unwritten bytes are undefined. */ + write_gran_1056bytes, /* If less than 1056 bytes are written, the unwritten bytes are undefined. */ }; /* Modified: trunk/flashrom.c ============================================================================== --- trunk/flashrom.c Mon Apr 1 02:46:05 2013 (r1665) +++ trunk/flashrom.c Mon Apr 1 21:34:53 2013 (r1666) @@ -688,6 +688,23 @@ return ret; } +/* Helper function for need_erase() that focuses on granularities of gran bytes. */ +static int need_erase_gran_bytes(uint8_t *have, uint8_t *want, unsigned int len, unsigned int gran) +{ + unsigned int i, j, limit; + for (j = 0; j < len / gran; j++) { + limit = min (gran, len - j * gran); + /* Are 'have' and 'want' identical? */ + if (!memcmp(have + j * gran, want + j * gran, limit)) + continue; + /* have needs to be in erased state. */ + for (i = 0; i < limit; i++) + if (have[j * gran + 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 @@ -705,7 +722,7 @@ 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: @@ -723,20 +740,22 @@ } 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_gran_bytes(have, want, len, 256); + break; + case write_gran_264bytes: + result = need_erase_gran_bytes(have, want, len, 264); + break; + case write_gran_512bytes: + result = need_erase_gran_bytes(have, want, len, 512); + break; + case write_gran_528bytes: + result = need_erase_gran_bytes(have, want, len, 528); + break; + case write_gran_1024bytes: + result = need_erase_gran_bytes(have, want, len, 1024); + break; + case write_gran_1056bytes: + result = need_erase_gran_bytes(have, want, len, 1056); break; default: msg_cerr("%s: Unsupported granularity! Please report a bug at " @@ -784,6 +803,21 @@ case write_gran_256bytes: stride = 256; break; + case write_gran_264bytes: + stride = 264; + break; + case write_gran_512bytes: + stride = 512; + break; + case write_gran_528bytes: + stride = 528; + break; + case write_gran_1024bytes: + stride = 1024; + break; + case write_gran_1056bytes: + stride = 1056; + break; default: msg_cerr("%s: Unsupported granularity! Please report a bug at " "[email protected]\n", __func__); _______________________________________________ flashrom mailing list [email protected] http://www.flashrom.org/mailman/listinfo/flashrom
