#endif
return 0;
}
+
+// Return values
+#define SUCCESS 0x01
+#define FAILURE 0x00
+
+// READSECTOR
+// Read a 512 byte sector from the SD CARD
+// Given SECTORNUMBER and memory STORAGE
+//
+// Sequence
+// Send CMD17 - Read Block
+// Command Sequence is DUMMY=0xff CMD17=0x51 SECTORNUMBER (32bit UNSIGNED as bits 32-25,24-17, 16-9, 8-1) CRC=0xff
+// Wait for SD CARD to send 0x00 indicating SD CARD is processing
+// Wait for SD CARD to send 0xfe indicating SD CARD BLOCK START
+// Read 512 bytes
+// Read 8 DUMMY bytes
+// Return 0 success, 1 failure
+//
+// Details from https://openlabpro.com/guide/interfacing-microcontrollers-with-sd-card/ section "Read/Write SD Card"
+uint8_t readSector(uint32_t sectorNumber, uint8_t *storage);
+uint8_t readSector(uint32_t sectorNumber, uint8_t *storage)
+{
+ int n;
+
+ // FIXME: handle errors.
+
+ sdcard_read(sectorNumber, 1);
+ for(n=0; n<512; n++)
+ storage[n] = sdread_buf[n];
+
+ return SUCCESS;
+}
+
+// FAT16 Specific code starts here
+// Details from https://codeandlife.com/2012/04/02/simple-fat-and-sd-tutorial-part-1/
+
+// Structure to store SD CARD partition table
+typedef struct {
+ uint8_t first_byte;
+ uint8_t start_chs[3];
+ uint8_t partition_type;
+ uint8_t end_chs[3];
+ uint32_t start_sector;
+ uint32_t length_sectors;
+} __attribute((packed)) PartitionTable;
+
+PartitionTable sdCardPartition;
+
+// Structure to store SD CARD FAT16 Boot Sector (boot code is ignored, provides layout of the FAT16 partition on the SD CARD)
+typedef struct {
+ uint8_t jmp[3];
+ uint8_t oem[8];
+ uint16_t sector_size;
+ uint8_t sectors_per_cluster;
+ uint16_t reserved_sectors;
+ uint8_t number_of_fats;
+ uint16_t root_dir_entries;
+ uint16_t total_sectors_short; // if zero, later field is used
+ uint8_t media_descriptor;
+ uint16_t fat_size_sectors;
+ uint16_t sectors_per_track;
+ uint16_t number_of_heads;
+ uint32_t hidden_sectors;
+ uint32_t total_sectors_long;
+
+ uint8_t drive_number;
+ uint8_t current_head;
+ uint8_t boot_signature;
+ uint32_t volume_id;
+ uint8_t volume_label[11];
+ uint8_t fs_type[8];
+ uint8_t boot_code[448];
+ uint16_t boot_sector_signature;
+} __attribute((packed)) Fat16BootSector;
+
+Fat16BootSector sdCardFatBootSector;
+
+// Structure to store SD CARD FAT16 Root Directory Entries
+// Allocated to MAIN RAM - hence pointer
+typedef struct {
+ uint8_t filename[8];
+ uint8_t ext[3];
+ uint8_t attributes;
+ uint8_t reserved[10];
+ uint16_t modify_time;
+ uint16_t modify_date;
+ uint16_t starting_cluster;
+ uint32_t file_size;
+} __attribute((packed)) Fat16Entry;
+
+Fat16Entry *sdCardFat16RootDir;
+
+// Structure to store SD CARD FAT16 Entries
+// Array of uint16_tS (16bit integers)
+uint16_t *sdCardFatTable;
+
+// Calculated sector numbers on the SD CARD for the FAT16 Entries and ROOT DIRECTORY
+uint32_t fatSectorStart, rootDirSectorStart;
+
+// Storage for SECTOR read from SD CARD
+uint8_t sdCardSector[512];
+
+// SPI_SDCARD_READMBR
+// Function exposed to BIOS to retrieve FAT16 partition details, FAT16 Entry Table, FAT16 Root Directory
+// MBR = Master Boot Record - Sector 0x00000000 on SD CARD - Contains Partition 1 details at 0x1be
+//
+// FIXME only checks partition 1 out of 4
+//
+// Return 0 success, 1 failure
+//
+// Details from https://codeandlife.com/2012/04/02/simple-fat-and-sd-tutorial-part-1/
+uint8_t spi_sdcard_readMBR(void)
+{
+ int i, n;
+
+ // Read Sector 0x00000000
+ printf("Reading MBR\n");
+ if( readSector(0x00000000, sdCardSector)==SUCCESS ) {
+ // Copy Partition 1 Entry from byte 0x1be
+ // FIXME should check 0x55 0xaa at end of sector
+ memcpy(&sdCardPartition, &sdCardSector[0x1be], sizeof(PartitionTable));
+
+ // Check Partition 1 is valid, FIRST_BYTE=0x00 or 0x80
+ // Check Partition 1 has type 4, 6 or 14 (FAT16 of various sizes)
+ printf("Partition 1 Information: Active=0x%02x, Type=0x%02x, LBAStart=0x%08x\n", sdCardPartition.first_byte, sdCardPartition.partition_type, sdCardPartition.start_sector);
+ if( (sdCardPartition.first_byte!=0x80) && (sdCardPartition.first_byte!=0x00) ) {
+ printf("Partition 1 Not Valid\n");
+ return FAILURE;
+ }
+ if( (sdCardPartition.partition_type==4) || (sdCardPartition.partition_type==6) || (sdCardPartition.partition_type==14) ) {
+ printf("Partition 1 is FAT16\n");
+ }
+ else {
+ printf("Partition 1 Not FAT16\n");
+ return FAILURE;
+ }
+ }
+ else {
+ printf("Failed to read MBR\n");
+ return FAILURE;
+ }
+
+ // Read Parition 1 Boot Sector - Found from Partion Table
+ printf("\nRead FAT16 Boot Sector\n");
+ sdCardPartition.start_sector = sdCardPartition.start_sector/512;
+ if( readSector(sdCardPartition.start_sector, sdCardSector)==SUCCESS ) {
+ memcpy(&sdCardFatBootSector, &sdCardSector, sizeof(Fat16BootSector));
+ }
+ else {
+ printf("Failed to read FAT16 Boot Sector\n");
+ return FAILURE;
+ }
+
+ // Print details of Parition 1
+ printf(" Jump Code: 0x%02x 0x%02x 0x%02x\n",sdCardFatBootSector.jmp[0],sdCardFatBootSector.jmp[1],sdCardFatBootSector.jmp[2]);
+ printf(" OEM Code: [");
+ for(n=0; n<8; n++)
+ printf("%c",sdCardFatBootSector.oem[n]);
+ printf("]\n");
+ printf(" Sector Size: %d\n",sdCardFatBootSector.sector_size);
+ printf(" Sectors Per Cluster: %d\n",sdCardFatBootSector.sectors_per_cluster);
+ printf(" Reserved Sectors: %d\n",sdCardFatBootSector.reserved_sectors);
+ printf(" Number of Fats: %d\n",sdCardFatBootSector.number_of_fats);
+ printf(" Root Dir Entries: %d\n",sdCardFatBootSector.root_dir_entries);
+ printf(" Total Sectors Short: %d\n",sdCardFatBootSector.total_sectors_short);
+ printf(" Media Descriptor: 0x%02x\n",sdCardFatBootSector.media_descriptor);
+ printf(" Fat Size Sectors: %d\n",sdCardFatBootSector.fat_size_sectors);
+ printf(" Sectors Per Track: %d\n",sdCardFatBootSector.sectors_per_track);
+ printf(" Number of Heads: %d\n",sdCardFatBootSector.number_of_heads);
+ printf(" Hidden Sectors: %d\n",sdCardFatBootSector.hidden_sectors);
+ printf(" Total Sectors Long: %d\n",sdCardFatBootSector.total_sectors_long);
+ printf(" Drive Number: 0x%02x\n",sdCardFatBootSector.drive_number);
+ printf(" Current Head: 0x%02x\n",sdCardFatBootSector.current_head);
+ printf(" Boot Signature: 0x%02x\n",sdCardFatBootSector.boot_signature);
+ printf(" Volume ID: 0x%08x\n",sdCardFatBootSector.volume_id);
+ printf(" Volume Label: [");
+ for(n=0; n<11; n++)
+ printf("%c",sdCardFatBootSector.volume_label[n]);
+ printf("]\n");
+ printf(" Volume Label: [");
+ for(n=0; n<8; n++)
+ printf("%c",sdCardFatBootSector.fs_type[n]);
+ printf("]\n");
+ printf(" Boot Sector Signature: 0x%04x\n\n",sdCardFatBootSector.boot_sector_signature);
+
+ // Check Partition 1 is valid, not 0 length
+ if(sdCardFatBootSector.total_sectors_long==0) {
+ printf("Error reading FAT16 Boot Sector\n");
+ return FAILURE;
+ }
+
+ // Read in FAT16 File Allocation Table, array of 16bit unsinged integers
+ // Calculate Storage from TOP of MAIN RAM
+ sdCardFatTable = (uint16_t *)(MAIN_RAM_BASE+MAIN_RAM_SIZE-sdCardFatBootSector.sector_size*sdCardFatBootSector.fat_size_sectors);
+ printf("sdCardFatTable = 0x%08x Reading Fat16 Table (%d Sectors Long)\n\n",sdCardFatTable,sdCardFatBootSector.fat_size_sectors);
+
+ // Calculate Start of FAT16 File Allocation Table (start of partition plus reserved sectors)
+ fatSectorStart=sdCardPartition.start_sector+sdCardFatBootSector.reserved_sectors;
+ for(n=0; n<sdCardFatBootSector.fat_size_sectors; n++) {
+ if( readSector(fatSectorStart+n, (uint8_t *)((uint8_t*)sdCardFatTable)+sdCardFatBootSector.sector_size*n)==FAILURE ) {
+ printf("Error reading FAT16 table - sector %d\n",n);
+ return FAILURE;
+ }
+ }
+
+ // Read in FAT16 Root Directory
+ // Calculate Storage from TOP of MAIN RAM
+ sdCardFat16RootDir= (Fat16Entry *)(MAIN_RAM_BASE+MAIN_RAM_SIZE-sdCardFatBootSector.sector_size*sdCardFatBootSector.fat_size_sectors-sdCardFatBootSector.root_dir_entries*sizeof(Fat16Entry));
+ printf("sdCardFat16RootDir = 0x%08x Reading Root Directory (%d Sectors Long)\n\n",sdCardFat16RootDir,sdCardFatBootSector.root_dir_entries*sizeof(Fat16Entry)/sdCardFatBootSector.sector_size);
+
+ // Calculate Start of FAT ROOT DIRECTORY (start of partition plues reserved sectors plus size of File Allocation Table(s))
+ rootDirSectorStart=sdCardPartition.start_sector+sdCardFatBootSector.reserved_sectors+sdCardFatBootSector.number_of_fats*sdCardFatBootSector.fat_size_sectors;
+ for(n=0; n<sdCardFatBootSector.root_dir_entries*sizeof(Fat16Entry)/sdCardFatBootSector.sector_size; n++) {
+ if( readSector(rootDirSectorStart+n, (uint8_t *)(sdCardFatBootSector.sector_size*n+(uint8_t *)(sdCardFat16RootDir)))==FAILURE ) {
+ printf("Error reading Root Dir - sector %d\n",n);
+ return FAILURE;
+ }
+ }
+
+ // Print out Root Directory
+ // Alternates between valid and invalid directory entries for SIMPLE 8+3 file names, extended filenames in other entries
+ // Only print valid characters
+ printf("\nRoot Directory\n");
+ for(n=0; n<sdCardFatBootSector.root_dir_entries; n++) {
+ if( (sdCardFat16RootDir[n].filename[0]!=0) && (sdCardFat16RootDir[n].file_size>0)) {
+ printf(" File %d [",n);
+ for( i=0; i<8; i++) {
+ if( (sdCardFat16RootDir[n].filename[i]>31) && (sdCardFat16RootDir[n].filename[i]<127) )
+ printf("%c",sdCardFat16RootDir[n].filename[i]);
+ else
+ printf(" ");
+ }
+ printf(".");
+ for( i=0; i<3; i++) {
+ if( (sdCardFat16RootDir[n].ext[i]>31) && (sdCardFat16RootDir[n].ext[i]<127) )
+ printf("%c",sdCardFat16RootDir[n].ext[i]);
+ else
+ printf(" ");
+ }
+ printf("] @ Cluster %d for %d bytes\n",sdCardFat16RootDir[n].starting_cluster,sdCardFat16RootDir[n].file_size);
+ }
+ }
+
+ printf("\n");
+ return SUCCESS;
+}
+
+// SPI_SDCARD_READFILE
+// Function exposed to BIOS to retrieve FILENAME+EXT into ADDRESS
+//
+// FIXME only checks UPPERCASE 8+3 filenames
+//
+// Return 0 success, 1 failure
+//
+// Details from https://codeandlife.com/2012/04/02/simple-fat-and-sd-tutorial-part-1/
+uint8_t spi_sdcard_readFile(char *filename, char *ext, unsigned long address)
+{
+ int i, n, sector;
+ uint16_t fileClusterStart;
+ uint32_t fileLength, bytesRemaining, clusterSectorStart;
+ uint16_t nameMatch;
+ printf("Reading File [%s.%s] into 0x%08x : ",filename, ext, address);
+
+ // Find FILENAME+EXT in Root Directory
+ // Indicate FILE found by setting the starting cluster number
+ fileClusterStart=0; n=0;
+ while( (fileClusterStart==0) && (n<sdCardFatBootSector.root_dir_entries) ) {
+ nameMatch=0;
+ if( sdCardFat16RootDir[n].filename[0]!=0 ) {
+ nameMatch=1;
+ for(i=0; i<strlen(filename); i++)
+ if(sdCardFat16RootDir[n].filename[i]!=filename[i]) nameMatch=0;
+ for(i=0; i<strlen(ext); i++)
+ if(sdCardFat16RootDir[n].ext[i]!=ext[i]) nameMatch=0;
+ }
+
+ if(nameMatch==1) {
+ fileClusterStart=sdCardFat16RootDir[n].starting_cluster;
+ fileLength=sdCardFat16RootDir[n].file_size;
+ } else {
+ n++;
+ }
+ }
+
+ // If starting cluster number is still 0 then file not found
+ if(fileClusterStart==0) {
+ printf("File not found\n");
+ return FAILURE;
+ }
+
+ printf("File starts at Cluster %d length %d\n",fileClusterStart,fileLength);
+
+ // ZERO Length file are automatically assumed to have been read SUCCESS
+ if( fileLength==0 ) return SUCCESS;
+
+ // Read each cluster sector by sector, i being number of clusters
+ bytesRemaining=fileLength;
+ // Calculate number of clusters (always >1)
+ for(i=0; i<1+((fileLength/sdCardFatBootSector.sectors_per_cluster)/sdCardFatBootSector.sector_size); i++) {
+ printf("\rCluster: %d",fileClusterStart);
+
+ // Locate start of cluster on SD CARD and read appropraite number of sectors
+ clusterSectorStart=rootDirSectorStart+(fileClusterStart-1)*sdCardFatBootSector.sectors_per_cluster;
+ for(sector=0; sector<sdCardFatBootSector.sectors_per_cluster; sector++) {
+ // Read Sector from SD CARD
+ // If whole sector to be read, read directly into memory
+ // Otherwise, read to sdCardSector buffer and transfer appropriate number of bytes
+ if(bytesRemaining>sdCardFatBootSector.sector_size) {
+ if( readSector(clusterSectorStart+sector,(uint8_t *)address) == FAILURE ) {
+ printf("\nRead Error\n");
+ return FAILURE;
+ }
+ bytesRemaining=bytesRemaining-sdCardFatBootSector.sector_size;
+ address=address+sdCardFatBootSector.sector_size;
+ } else {
+ if( readSector(clusterSectorStart+sector,sdCardSector) == FAILURE ) {
+ printf("\nRead Error\n");
+ return FAILURE;
+ }
+ memcpy((uint8_t *)address, sdCardSector, bytesRemaining);
+ bytesRemaining=0;
+ }
+ }
+
+ // Move to next cluster
+ fileClusterStart=sdCardFatTable[fileClusterStart];
+ }
+ printf("\n\n");
+ return SUCCESS;
+}
+
#endif /* CSR_SDCORE_BASE */
projects / litex.git / commitdiff