diff options
Diffstat (limited to 'firmware')
| -rw-r--r-- | firmware/target/arm/imx233/partitions-imx233.c | 26 |
1 files changed, 17 insertions, 9 deletions
diff --git a/firmware/target/arm/imx233/partitions-imx233.c b/firmware/target/arm/imx233/partitions-imx233.c index 60c36ebb4d..bb322162c9 100644 --- a/firmware/target/arm/imx233/partitions-imx233.c +++ b/firmware/target/arm/imx233/partitions-imx233.c @@ -125,14 +125,22 @@ static int compute_window_freescale(intptr_t user, part_read_fn_t read_fn, * The first table uses 512-byte sector size and the second one usually uses * 2048-byte logical sector size. * - * We restrict the window to the user partition - * * WARNING HACK FIXME BUG - * Reverse engineering and experiments suggests that the OF ignores the lowest 2 bits - * of the LBAs in the partition table. There is at least one example - * (the Creative Zen X-Fi3) where this is important because the LBA of the user partition - * is not a multiple of 4. The behaviour of the size field is less clear but - * it seems that it is similarly truncated. */ + * Reverse engineering suggests that OF has a notion of "internal sector size" + * which can either be 512 or 2048 bytes. When applied to the main data drive, + * it internally converts LBA from sectors to "internal sectors". Consequently, + * if the internal sector size is 2048 and the sector size of 512, it will + * drop the lowest 2 bits of the LBA from the partition table. This is the case + * of the ZEN X-Fi3 for example. However, if the internal sector size is 512 + * bytes, then there is no such loss. This is the case of the Zen X-Fi Style + * for example. + * The behaviour of the size field is less clear but it seems that it is similarly + * truncated. */ +#if defined(CREATIVE_ZENXFISTYLE) +#define DROP_MASK 0 +#else +#define DROP_MASK 3 +#endif if(mbr[510] != 0x55 || mbr[511] != 0xAA) return -101; /* invalid MBR */ if(part == IMX233_PART_DATA) @@ -141,9 +149,9 @@ static int compute_window_freescale(intptr_t user, part_read_fn_t read_fn, uint8_t *ent = &mbr[446]; *start = ent[8] | ent[9] << 8 | ent[10] << 16 | ent[11] << 24; /* ignore two lowest bits(see comment above) */ - *start &= ~3; + *start &= ~DROP_MASK; *end = (ent[12] | ent[13] << 8 | ent[14] << 16 | ent[15] << 24); - *end &= ~3; + *end &= ~DROP_MASK; /* ignore two lowest bits(order is important, first truncate then add start) */ *end += *start; |