nx_emmc_bis: Implement bis write

This commit is contained in:
shchmue 2020-07-02 14:10:44 -06:00
parent acc11300e5
commit 25aa483bd5
3 changed files with 127 additions and 19 deletions

View File

@ -89,7 +89,7 @@ DRESULT disk_write (
return sdmmc_storage_write(&sd_storage, sector, count, (void *)buff) ? RES_OK : RES_ERROR;
case DRIVE_BIS:
return RES_WRPRT;
return nx_emmc_bis_write(sector, count, buff);
}
return RES_ERROR;

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@ -41,12 +41,19 @@ typedef struct
u8 cluster[XTS_CLUSTER_SIZE]; // the cached cluster itself
} cluster_cache_t;
typedef struct
{
u8 emmc_buffer[XTS_CLUSTER_SIZE];
cluster_cache_t cluster_cache[];
} bis_cache_t;
static u8 ks_crypt = 0;
static u8 ks_tweak = 0;
static u8 cache_filled = 0;
static u32 dirty_cluster_count = 0;
static u32 cluster_cache_end_index = 0;
static emmc_part_t *system_part = NULL;
static u8 *emmc_buffer = (u8 *)NX_BIS_CACHE_ADDR;
static cluster_cache_t *cluster_cache = (cluster_cache_t *)(NX_BIS_CACHE_ADDR + XTS_CLUSTER_SIZE);
static bis_cache_t *bis_cache = (bis_cache_t *)NX_BIS_CACHE_ADDR;
static u32 *cluster_lookup_buf = NULL;
static u32 *cluster_lookup = NULL;
static bool lock_cluster_cache = false;
@ -119,6 +126,59 @@ static int _nx_aes_xts_crypt_sec(u32 tweak_ks, u32 crypt_ks, u32 enc, u8 *tweak,
return 1;
}
static int nx_emmc_bis_write_block(u32 sector, u32 count, void *buff, bool force_flush)
{
if (!system_part)
return 3; // Not ready.
u8 tweak[0x10];
u32 cluster = sector / SECTORS_PER_CLUSTER;
u32 aligned_sector = cluster * SECTORS_PER_CLUSTER;
u32 sector_index_in_cluster = sector % SECTORS_PER_CLUSTER;
u32 cluster_lookup_index = cluster_lookup[cluster];
bool is_cached = cluster_lookup_index != CLUSTER_LOOKUP_EMPTY_ENTRY;
// Write to cached cluster.
if (is_cached)
{
if (buff)
memcpy(bis_cache->cluster_cache[cluster_lookup_index].cluster + sector_index_in_cluster * NX_EMMC_BLOCKSIZE, buff, count * NX_EMMC_BLOCKSIZE);
else
buff = bis_cache->cluster_cache[cluster_lookup_index].cluster;
bis_cache->cluster_cache[cluster_lookup_index].visit_count++;
if (bis_cache->cluster_cache[cluster_lookup_index].dirty == 0)
dirty_cluster_count++;
bis_cache->cluster_cache[cluster_lookup_index].dirty = 1;
if (!force_flush)
return 0; // Success.
// Reset args to trigger a full cluster flush to emmc.
sector_index_in_cluster = 0;
sector = aligned_sector;
count = SECTORS_PER_CLUSTER;
}
// Encrypt and write.
if (!_nx_aes_xts_crypt_sec(ks_tweak, ks_crypt, 1, tweak, true, sector_index_in_cluster, cluster, bis_cache->emmc_buffer, buff, count * NX_EMMC_BLOCKSIZE) ||
!nx_emmc_part_write(&emmc_storage, system_part, sector, count, bis_cache->emmc_buffer)
)
return 1; // R/W error.
// Mark cache entry not dirty if write succeeds.
if (is_cached)
{
bis_cache->cluster_cache[cluster_lookup_index].dirty = 0;
dirty_cluster_count--;
}
return 0; // Success.
}
static void _nx_emmc_bis_flush_cluster(cluster_cache_t *cache_entry)
{
nx_emmc_bis_write_block(cache_entry->cluster_num * SECTORS_PER_CLUSTER, SECTORS_PER_CLUSTER, NULL, true);
}
static int nx_emmc_bis_read_block(u32 sector, u32 count, void *buff)
{
if (!system_part)
@ -137,39 +197,48 @@ static int nx_emmc_bis_read_block(u32 sector, u32 count, void *buff)
u32 sector_index_in_cluster = sector % SECTORS_PER_CLUSTER;
u32 cluster_lookup_index = cluster_lookup[cluster];
// Read from cached cluster.
if (cluster_lookup_index != CLUSTER_LOOKUP_EMPTY_ENTRY)
{
memcpy(buff, cluster_cache[cluster_lookup_index].cluster + sector_index_in_cluster * NX_EMMC_BLOCKSIZE, count * NX_EMMC_BLOCKSIZE);
cluster_cache[cluster_lookup_index].visit_count++;
memcpy(buff, bis_cache->cluster_cache[cluster_lookup_index].cluster + sector_index_in_cluster * NX_EMMC_BLOCKSIZE, count * NX_EMMC_BLOCKSIZE);
bis_cache->cluster_cache[cluster_lookup_index].visit_count++;
prev_sector = sector + count - 1;
prev_cluster = cluster;
return 0; // Success.
}
// Only cache single-sector reads as these are most likely to be repeated, such as boot block and FAT directory tables.
if (!lock_cluster_cache &&
cluster_cache_end_index < MAX_CLUSTER_CACHE_ENTRIES)
// Cache cluster.
if (!lock_cluster_cache)
{
cluster_cache[cluster_cache_end_index].cluster_num = cluster;
cluster_cache[cluster_cache_end_index].visit_count = 1;
cluster_cache[cluster_cache_end_index].dirty = 0;
// Roll the cache index over and flush if full.
if (cluster_cache_end_index >= MAX_CLUSTER_CACHE_ENTRIES)
{
cluster_cache_end_index = 0;
cache_filled = 1;
}
// Check if cache entry was previously in use in case of cache loop.
if (cache_filled == 1 && bis_cache->cluster_cache[cluster_cache_end_index].dirty == 1)
_nx_emmc_bis_flush_cluster(&bis_cache->cluster_cache[cluster_cache_end_index]);
bis_cache->cluster_cache[cluster_cache_end_index].cluster_num = cluster;
bis_cache->cluster_cache[cluster_cache_end_index].visit_count = 1;
bis_cache->cluster_cache[cluster_cache_end_index].dirty = 0;
cluster_lookup[cluster] = cluster_cache_end_index;
// Read and decrypt the whole cluster the sector resides in.
if (!nx_emmc_part_read(&emmc_storage, system_part, aligned_sector, SECTORS_PER_CLUSTER, emmc_buffer))
return 1; // R/W error.
if (!_nx_aes_xts_crypt_sec(ks_tweak, ks_crypt, 0, cache_tweak, true, 0, cluster, emmc_buffer, emmc_buffer, XTS_CLUSTER_SIZE))
if (!nx_emmc_part_read(&emmc_storage, system_part, aligned_sector, SECTORS_PER_CLUSTER, bis_cache->emmc_buffer) ||
!_nx_aes_xts_crypt_sec(ks_tweak, ks_crypt, 0, cache_tweak, true, 0, cluster, bis_cache->emmc_buffer, bis_cache->emmc_buffer, XTS_CLUSTER_SIZE)
)
return 1; // R/W error.
// Copy to cluster cache.
memcpy(cluster_cache[cluster_cache_end_index].cluster, emmc_buffer, XTS_CLUSTER_SIZE);
memcpy(buff, emmc_buffer + sector_index_in_cluster * NX_EMMC_BLOCKSIZE, NX_EMMC_BLOCKSIZE * count);
memcpy(bis_cache->cluster_cache[cluster_cache_end_index].cluster, bis_cache->emmc_buffer, XTS_CLUSTER_SIZE);
memcpy(buff, bis_cache->emmc_buffer + sector_index_in_cluster * NX_EMMC_BLOCKSIZE, count * NX_EMMC_BLOCKSIZE);
cluster_cache_end_index++;
return 0; // Success.
}
// If not reading from or writing to cache, do a regular read and decrypt.
if (!nx_emmc_part_read(&emmc_storage, system_part, sector, count, buff))
if (!nx_emmc_part_read(&emmc_storage, system_part, sector, count, bis_cache->emmc_buffer))
return 1; // R/W error.
if (prev_cluster != cluster) // Sector in different cluster than last read.
@ -187,7 +256,7 @@ static int nx_emmc_bis_read_block(u32 sector, u32 count, void *buff)
tweak_exp = sector_index_in_cluster;
// Maximum one cluster (1 XTS crypto block 16KB).
if (!_nx_aes_xts_crypt_sec(ks_tweak, ks_crypt, 0, tweak, regen_tweak, tweak_exp, prev_cluster, buff, buff, count * NX_EMMC_BLOCKSIZE))
if (!_nx_aes_xts_crypt_sec(ks_tweak, ks_crypt, 0, tweak, regen_tweak, tweak_exp, prev_cluster, buff, bis_cache->emmc_buffer, count * NX_EMMC_BLOCKSIZE))
return 1; // R/W error.
prev_sector = sector + count - 1;
@ -215,6 +284,27 @@ int nx_emmc_bis_read(u32 sector, u32 count, void *buff)
return res;
}
int nx_emmc_bis_write(u32 sector, u32 count, void *buff)
{
int res = 1;
u8 *buf = (u8 *)buff;
u32 curr_sct = sector;
while (count)
{
u32 sct_cnt = MIN(count, 0x20);
res = nx_emmc_bis_write_block(curr_sct, sct_cnt, buf, false);
if (res)
return 1;
count -= sct_cnt;
curr_sct += sct_cnt;
buf += NX_EMMC_BLOCKSIZE * sct_cnt;
}
return res;
}
void nx_emmc_bis_cluster_cache_init()
{
u32 cluster_lookup_size = (system_part->lba_end - system_part->lba_start + 1) / SECTORS_PER_CLUSTER * sizeof(*cluster_lookup);
@ -239,6 +329,9 @@ void nx_emmc_bis_cluster_cache_init()
memset(cluster_lookup, -1, cluster_lookup_size);
cluster_cache_end_index = 0;
lock_cluster_cache = false;
dirty_cluster_count = 0;
cache_filled = 0;
}
void nx_emmc_bis_init(emmc_part_t *part)
@ -266,6 +359,19 @@ void nx_emmc_bis_init(emmc_part_t *part)
}
}
void nx_emmc_bis_finalize()
{
if (dirty_cluster_count == 0)
return;
u32 limit = cache_filled == 1 ? MAX_CLUSTER_CACHE_ENTRIES : cluster_cache_end_index;
for (u32 i = 0; i < limit; i++)
{
if (bis_cache->cluster_cache[i].dirty)
_nx_emmc_bis_flush_cluster(&bis_cache->cluster_cache[i]);
}
}
// Set cluster cache lock according to arg.
void nx_emmc_bis_cache_lock(bool lock)
{

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@ -225,8 +225,10 @@ typedef struct _nx_emmc_cal0_t
} __attribute__((packed)) nx_emmc_cal0_t;
int nx_emmc_bis_read(u32 sector, u32 count, void *buff);
int nx_emmc_bis_write(u32 sector, u32 count, void *buff);
void nx_emmc_bis_cluster_cache_init();
void nx_emmc_bis_init(emmc_part_t *part);
void nx_emmc_bis_finalize();
void nx_emmc_bis_cache_lock(bool lock);
#endif