diff --git a/sw/kernel/filesystem/fat.c b/sw/kernel/filesystem/fat.c index e07359a..669b0a5 100644 --- a/sw/kernel/filesystem/fat.c +++ b/sw/kernel/filesystem/fat.c @@ -1,55 +1,65 @@ #include #include +#include #include "fat.h" #include "devices/sd_card.h" uint8_t fat_buf[512]; +static uint32_t fat_end_of_chain; + static full_bpb_t bpb; static uint32_t data_region_start; -void fat_print_pbp_info(ebpb_t* epbp){ - cprintf("Bytes per sector: %d\n", epbp->bpb3.bpb2.bytes_per_sector); - cprintf("Sectors per cluster: %d\n", epbp->bpb3.bpb2.sectors_per_cluster); - cprintf("Reserved Sectors: %d\n", epbp->bpb3.bpb2.reserved_sectors); - cprintf("Fat Count: %d\n", epbp->bpb3.bpb2.fat_count); - cprintf("Max Dir Entries: %d\n", epbp->bpb3.bpb2.max_dir_entries); - cprintf("Total Sector Count: %d\n", epbp->bpb3.bpb2.total_sector_count); - cprintf("Media Descriptor: 0x%x\n", epbp->bpb3.bpb2.media_descriptor); - cprintf("Sectors per Fat: %d\n", epbp->bpb3.bpb2.sectors_per_fat); +void fat_print_pbp_info(full_bpb_t* bpb){ + cprintf("Bytes per sector: %d\n", bpb->bytes_per_sector); + cprintf("Sectors per cluster: %d\n", bpb->sectors_per_cluster); + cprintf("Reserved Sectors: %d\n", bpb->reserved_sectors); + cprintf("Fat Count: %d\n", bpb->fat_count); + cprintf("Max Dir Entries: %d\n", bpb->max_dir_entries); + cprintf("Total Sector Count: %d\n", bpb->total_sector_count); + cprintf("Media Descriptor: 0x%x\n", bpb->media_descriptor); + cprintf("Sectors per Fat: %d\n", bpb->sectors_per_fat_16); cprintf("\n"); - cprintf("Sectors per track: %d\n", epbp->bpb3.sectors_per_track); - cprintf("Head Count: %d\n", epbp->bpb3.head_count); - cprintf("Hidden Sector Count: %ld\n", epbp->bpb3.hidden_sector_count); - cprintf("Logical Sector Count: %ld\n", epbp->bpb3.logical_sector_count); - cprintf("Sectors per Fat: %ld\n", epbp->bpb3.sectors_per_fat); - cprintf("Extended Flags: 0x%x\n", epbp->bpb3.extended_flags); - cprintf("Version: %d\n", epbp->bpb3.version); - cprintf("Root Cluster: 0x%lx\n", epbp->bpb3.root_cluster); - cprintf("System Information: 0x%x\n", epbp->bpb3.system_information); - cprintf("Backup Boot Sector: 0x%x\n", epbp->bpb3.backup_boot_sector); + cprintf("Sectors per track: %d\n", bpb->sectors_per_track); + cprintf("Head Count: %d\n", bpb->head_count); + cprintf("Hidden Sector Count: %ld\n", bpb->hidden_sector_count); + cprintf("Logical Sector Count: %ld\n", bpb->logical_sector_count); + cprintf("Sectors per Fat: %ld\n", bpb->sectors_per_fat_32); + cprintf("Extended Flags: 0x%x\n", bpb->extended_flags); + cprintf("Version: %d\n", bpb->version); + cprintf("Root Cluster: 0x%lx\n", bpb->root_cluster); + cprintf("System Information: 0x%x\n", bpb->system_information); + cprintf("Backup Boot Sector: 0x%x\n", bpb->backup_boot_sector); cprintf("\n"); - cprintf("Drive Number: %d\n", epbp->drive_num); - cprintf("Extended Signature: 0x%x\n", epbp->extended_signature); - cprintf("Volume ID: 0x%lx\n", epbp->volume_id); - cprintf("Partition Label: %.11s\n", &epbp->partition_label); - cprintf("Partition Label: %.8s\n", &epbp->filesystem_type); + cprintf("Drive Number: %d\n", bpb->drive_num); + cprintf("Extended Signature: 0x%x\n", bpb->extended_signature); + cprintf("Volume ID: 0x%lx\n", bpb->volume_id); + cprintf("Partition Label: %.11s\n", &bpb->partition_label); + cprintf("Partition Label: %.8s\n", &bpb->filesystem_type); cprintf("\n"); } void fat_init(){ sd_readblock(0, fat_buf); - memcpy(&bpb, &fat_buf[11], sizeof(ebpb_t)); + memcpy(&bpb, &fat_buf[11], sizeof(full_bpb_t)); sd_readblock(1, fat_buf); sd_readblock(32, fat_buf); + fat_print_pbp_info(&bpb); + data_region_start = bpb.reserved_sectors + bpb.fat_count*bpb.sectors_per_fat_32; + + sd_readblock(bpb.reserved_sectors, fat_buf); + + fat_end_of_chain = ((uint32_t*)fat_buf)[1] & FAT_EOC_CLUSTERMASK; + cprintf("End of chain indicator: %lx\n", fat_end_of_chain); } void fat_read(char* filename, void* buf) { @@ -71,3 +81,135 @@ void fat_read(char* filename, void* buf) { sd_readblock(data_region_start + (cluster - 2) * 8, buf); } + +//the dentry is a double pointer because we need to increment it. +void fat_parse_vfat_filenamename(vfat_dentry_t** vfat_dentry, char* name) { + uint8_t i; + uint8_t done; + char* shift_name; + uint8_t sequence_number = (*vfat_dentry)->sequence_number; + + // so basically we want to add 13*(sequence number-1) to name + + for (;;){ + shift_name = name + 13*((sequence_number & FAT_LFN_ENTRY_MASK) - 1); + + done = 0; + for(i = 0; i < 5; i++) { + shift_name[i] = (*vfat_dentry)->filename0[i]; + if (!shift_name[i]) { + done = 1; + break; + } + } + + if (!done) { + for(i = 0; i < 6; i++) { + shift_name[i+5] = (*vfat_dentry)->filename1[i]; + if (!shift_name[i+5]) { + done = 1; + break; + } + } + } + + if (!done) { + for(i = 0; i < 2; i++) { + shift_name[i+11] = (*vfat_dentry)->filename2[i]; + if (!shift_name[i+11]) { + done = 1; + break; + } + } + } + + if ((sequence_number & FAT_LFN_ENTRY_MASK) == 1) { + break; + } else { + (*vfat_dentry)++; + while((*vfat_dentry)->sequence_number == 0xe5) + (*vfat_dentry)++; + sequence_number = (*vfat_dentry)->sequence_number; + } + } + +} + +uint32_t fat_find_cluster_num(char* name, uint32_t cluster) { + vfat_dentry_t* vfat_dentry; + dos_dentry_t* dos_dentry; + char* vfat_name; + + cprintf("Looking for file %s\n", name); + + sd_readblock(data_region_start + (cluster - 2) * 8, fat_buf); + vfat_dentry = (vfat_dentry_t*)fat_buf; + + vfat_name = (char*)malloc(FAT_MAX_FILE_NAME); + + while(vfat_dentry->sequence_number == 0xe5) + vfat_dentry++; + + vfat_name[0] = '\0'; + + while(vfat_dentry->sequence_number) { + fat_parse_vfat_filenamename(&vfat_dentry, vfat_name); + cprintf("Parsed filename: %s\n", vfat_name); + + if (!strcmp(vfat_name, name)) { //TODO this is probably unsafe, use strncmp + cprintf("Found file %s\n", vfat_name); + break; + } else { + vfat_dentry += 2; + while(vfat_dentry->sequence_number == 0xe5) + vfat_dentry++; + } + } + + free(vfat_name); + + if (!vfat_dentry->sequence_number) { + cprintf("File not found.\n"); + return -1; + } + + dos_dentry = (dos_dentry_t*) vfat_dentry + 1; //dos entry follows last vfat entry + + cluster = ((uint32_t)dos_dentry->first_cluster_h << 16) + dos_dentry->first_cluster_l; + cprintf("Cluster: %ld\n", cluster); + + return cluster; +} + +uint16_t fat_parse_path_to_cluster(char* filename) { + //basically start at the root folder and search through it + int i; + int len; + + char* spaced_filename; + + uint32_t cluster = 2; //root chain is chain 2 + + if (filename[0] != '/') { + cprintf("Filename does not begin with '/'\n"); + return 0; + } + + filename++; + len = strlen(filename); + spaced_filename = (char*)malloc(len+1); //need to account for null byte + + for (i = 0; i <= len; i++) { + if (filename[i] == '/') { + spaced_filename[i] = '\0'; + } else { + spaced_filename[i] = filename[i]; + } + } + + cprintf("Fragment: %s\n", spaced_filename); + + fat_find_cluster_num(spaced_filename, cluster); + + free(spaced_filename); +} diff --git a/sw/kernel/filesystem/fat.h b/sw/kernel/filesystem/fat.h index bf374ab..9c26b5b 100644 --- a/sw/kernel/filesystem/fat.h +++ b/sw/kernel/filesystem/fat.h @@ -5,6 +5,15 @@ extern uint8_t fat_buf[]; +#define FAT_MAX_FILE_NAME 255 +#define FAT_CLUSTERS_PER_SECTOR 128 + +#define FAT_CLUSTERMASK 0x0fffffff +#define FAT_EOC_CLUSTERMASK 0x0ffffff8 + +#define FAT_LAST_LFN_MASK (1 << 6) +#define FAT_LFN_ENTRY_MASK 0x1f + typedef struct { uint16_t bytes_per_sector; uint8_t sectors_per_cluster; @@ -87,7 +96,7 @@ typedef struct { uint8_t checksum; uint16_t filename1[6]; uint16_t reserved; - uint16_t filename[2]; + uint16_t filename2[2]; } vfat_dentry_t; typedef struct { @@ -104,8 +113,10 @@ typedef struct { uint32_t file_size; } dos_dentry_t; -void fat_print_pbp_info(ebpb_t* epbp); +void fat_print_pbp_info(full_bpb_t* bpb); void fat_init(); void fat_read(char* filename, void* buf); +uint16_t fat_parse_path_to_cluster(char* filename); + #endif diff --git a/sw/kernel/main.c b/sw/kernel/main.c index c753882..21850fd 100644 --- a/sw/kernel/main.c +++ b/sw/kernel/main.c @@ -1,6 +1,7 @@ #include #include #include +#include #include "devices/board_io.h" #include "devices/uart.h" @@ -14,6 +15,7 @@ uint8_t buf[512]; int main() { int i; uint16_t rca; + char* filename; clrscr(); cprintf("Hello, world!\n"); @@ -34,7 +36,17 @@ int main() { sd_select_card(rca); fat_init(); - exec("/test.o65"); + + filename = (char*)malloc(FAT_MAX_FILE_NAME); + + for(;;) { + cprintf("Filename: "); + cscanf("%s", filename); + cprintf("\n"); + fat_parse_path_to_cluster(filename); + } + + //exec("/test.o65"); cprintf("Done!\n");