diff options
Diffstat (limited to 'chud.c')
| -rw-r--r-- | chud.c | 418 |
1 files changed, 0 insertions, 418 deletions
@@ -1,418 +0,0 @@ -/* - * CHU - driver for CH375 in disk mode - * Copyright (C) 2024 Javier S. Pedro - * - * This program is free software: you can redistribute it and/or modify - * it under the terms of the GNU General Public License as published by - * the Free Software Foundation, either version 3 of the License, or - * (at your option) any later version. - - * This program is distributed in the hope that it will be useful, - * but WITHOUT ANY WARRANTY; without even the implied warranty of - * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the - * GNU General Public License for more details. - * - * You should have received a copy of the GNU General Public License - * along with this program. If not, see <https://www.gnu.org/licenses/>. - */ - -#include <stdio.h> -#include <stdlib.h> -#include <stdint.h> -#include <string.h> -#include <dos.h> -#include <dosfunc.h> -#include <io.h> - -#include "inc/mbr.h" -#include "inc/dosdrv.h" - -#include "chudisk.h" - -uint16_t ch375_port; - -bool read_only; -bool show_fat32; - -uint8_t drive; -uint32_t partition_start; -uint32_t partition_len; - -#define MAX_PARTITIONS 32 -struct partinfo { - uint32_t start_sector; - uint32_t num_sectors; - uint8_t type; -} partinfo[MAX_PARTITIONS]; -unsigned int num_parts; - -static int ioctl_read_control(uint8_t drive, void *buffer, int len) -{ - union REGS regs; - regs.h.ah = DOS_IOCTL; - regs.h.al = 0x04; // Read control string from block device - regs.x.bx = drive; - regs.x.cx = len; - regs.x.dx = FP_OFF(buffer); - - intdos(®s, ®s); - - if (regs.x.cflag) { - return -1; - } else { - return regs.x.ax; - } -} - -static int ioctl_write_control(uint8_t drive, void *buffer, int len) -{ - union REGS regs; - regs.h.ah = DOS_IOCTL; - regs.h.al = 0x05; // Write control string to block device - regs.x.bx = drive; - regs.x.cx = len; - regs.x.dx = FP_OFF(buffer); - - intdos(®s, ®s); - - if (regs.x.cflag) { - return -1; - } else { - return regs.x.ax; - } -} - -static int ioctl_read_abs_sector(uint8_t drive, void *buffer, uint32_t sector, int sectors) -{ - CHUDISK_IOCTL_DISK_DATA ciod; - union REGS regs; - - ciod.rwabs.buffer = buffer; - ciod.rwabs.sector = sector; - ciod.rwabs.sectors = sectors; - - regs.h.ah = DOS_IOCTL; - regs.h.al = 0x0D; // IOCTL for block devices - regs.x.bx = drive; - regs.h.ch = DOS_IOCTL_DISK; - regs.h.cl = CHUDISK_IOCTL_DISK_READ_ABS_SECTOR; - regs.x.dx = FP_OFF(&ciod); - - intdos(®s, ®s); - - return regs.x.cflag ? -1 : 0; -} - -static void dos_disk_reset() -{ - union REGS regs; - regs.h.ah = 0x0D; // DOS DISK RESET - - intdos(®s, ®s); -} - -static int parse_chudisk_control_string(const char *b, int len) -{ - // Not sure why I'm doing it this way instead of just sharing a pointer. - int i = 0; -#if 0 - printf("control string:\n"); - for (i = 0; i < len; i+=8) { - printf(" %hx %hx %hx %hx %hx %hx %hx %hx\n", - b[i+0], b[i+1], b[i+2], b[i+3], b[i+4], b[i+5], b[i+6], b[i+7]); - } - i = 0; -#endif - while (i < len) { - char c = b[i++]; - switch (c) { - case 'B': - memcpy(&ch375_port, &b[i], sizeof(ch375_port)); - i+=sizeof(ch375_port); - break; - case '3': - show_fat32 = b[i++]; - break; - case 'R': - read_only = b[i++]; - break; - case 'S': - memcpy(&partition_start, &b[i], sizeof(partition_start)); - i+=sizeof(partition_start); - break; - case 'L': - memcpy(&partition_len, &b[i], sizeof(partition_len)); - i+=sizeof(partition_len); - break; - case '\0': - return 0; - default: - fprintf(stderr, "Unidentified control string parameter: '%c'\n", c); - return -1; - } - } - - return 0; -} - -static bool is_selectable_partition(const MBR_PARTENTRY *partentry) -{ - return partentry->type == MBR_FAT12 || partentry->type == MBR_FAT16_32MB - || partentry->type == MBR_FAT16 || partentry->type == MBR_FAT16_LBA - || (show_fat32 && (partentry->type == MBR_FAT32 || partentry->type == MBR_FAT32_LBA)); -} - -static const char *get_partition_type(const MBR_PARTENTRY *partentry) -{ - static char buffer[8]; - switch (partentry->type) { - case MBR_EMPTY: - return "invalid"; - case MBR_FAT12: - return "fat12"; - case MBR_FAT16_32MB: - case MBR_FAT16: - case MBR_FAT16_LBA: - return "fat16"; - case MBR_IFS: - return "ntfs"; - case MBR_FAT32: - case MBR_FAT32_LBA: - return "fat32"; - case MBR_EXT: - case MBR_EXT_LBA: - return "extended"; - case MBR_LINUX: - case MBR_LINUX_SWAP: - return "linux"; - default: - sprintf(buffer, "%#X", partentry->type); - return buffer; - } -} - - -static const char * show_partition_size(const MBR_PARTENTRY *partentry) -{ - static char buffer[12]; - uint32_t size = partentry->lbaLen / 2; - STATIC_ASSERT(SECTOR_SIZE == 512); - - if (size <= 10000) { - sprintf(buffer, "%lu KB", size); - return buffer; - } - - size /= 1024; - if (size <= 10000) { - sprintf(buffer, "%lu MB", size); - return buffer; - } - - size /= 1024; - - sprintf(buffer, "%lu GB", size); - return buffer; -} - -static const char *get_partition_label(const MBR_PARTENTRY *partentry, const uint32_t start_sector) -{ - static char buffer[SECTOR_SIZE]; - DOS_BPB *bpb = (DOS_BPB*) &buffer[DOS_BPB_OFFSET_ON_DISK]; - - switch (partentry->type) { - // Focus on well-known types for now - case MBR_FAT12: - case MBR_FAT16_32MB: - case MBR_FAT16: - case MBR_FAT16_LBA: - case MBR_FAT32: - case MBR_FAT32_LBA: - break; - default: - return " "; - } - - if (ioctl_read_abs_sector(drive, buffer, start_sector, 1) != 0) { - fprintf(stderr, "while reading partition boot record at %lu: %s\n", start_sector, strerror(errno)); - return " ???? "; - } - - if (bpb->sectorsPerFAT != 0) { - // Assume FAT16 - return bpb->fat16.volumeLabel; - } else { - // Assume FAT32 - return bpb->fat32.volumeLabel; - } -} - -static void print_partition(const uint32_t mbr_sector, const MBR_PARTENTRY *partentry, bool selectable) -{ - const bool ebr = mbr_sector != 0; - const uint32_t start_sector = mbr_sector + partentry->lbaFirst; - const bool is_current = partition_start == start_sector; - const char *typeLabel = get_partition_type(partentry); - const char *volumeLabel = get_partition_label(partentry, start_sector); - const char *sizeLabel = show_partition_size(partentry); - - if (partentry->type == MBR_EMPTY) { - // Skip empty partitions no matter what - return; - } - if (ebr && (partentry->type == MBR_EXT || partentry->type == MBR_EXT_LBA)) { - // Skip displaying EXT partitions EBR, noisy - return; - } - - if (selectable) { - const unsigned index = num_parts + 1; - - printf(" %c[%2u] %8s %-11.11s %10s \n", - is_current ? '*' : ' ', index, typeLabel, volumeLabel, sizeLabel); - } else { - printf(" %c[ ] %8s %-11.11s %10s \n", - is_current ? '*' : ' ', typeLabel, volumeLabel, sizeLabel); - } - -} - -static int scan_disk_partitions() -{ - static char buffer[SECTOR_SIZE]; - uint32_t next_sector = 0; - - printf(" Index %8s %-11.11s %10s \n", - "Type", "Label", "Size"); - - // Start with MBR at sector 0 - next_sector = 0; - do { - const uint32_t this_sector = next_sector; - const MBR_PARTENTRY *partentry; - int i; - - // Try to read sector - if (ioctl_read_abs_sector(drive, buffer, this_sector, 1) != 0) { - fprintf(stderr, "while reading %s at disk sector %lu: %s\n", - this_sector == 0 ? "MBR" : "EBR", - this_sector, strerror(errno)); - // Fatal for MBR, non-fatal for EBR - if (this_sector == 0) { - fprintf(stderr, "is the disk present?\n"); - return -1; - } - break; - } - - // Check for signature - if (*(uint16_t*)&buffer[MBR_SIGNATURE_OFFSET_ON_DISK] != 0xAA55U) { - fprintf(stderr, "on disk sector %lu: invalid MBR signature %x\n", - this_sector, *(uint16_t*)&buffer[MBR_SIGNATURE_OFFSET_ON_DISK]); - if (this_sector == 0) return -1; - break; - } - - // Parse the MBR - partentry = (MBR_PARTENTRY*)&buffer[MBR_PARTENTRY_OFFSET_ON_DISK]; - - next_sector = 0; // If there is another EBR we will store it here - for (i = 0; i < 4 && num_parts < MAX_PARTITIONS; i++) { - bool is_selectable = is_selectable_partition(&partentry[i]); - - print_partition(this_sector, &partentry[i], is_selectable); - - if (is_selectable) { - partinfo[num_parts].type = partentry[i].type; - partinfo[num_parts].start_sector = this_sector + partentry[i].lbaFirst; - partinfo[num_parts].num_sectors = partentry[i].lbaLen; - num_parts++; - } - if (partentry[i].type == MBR_EXT || partentry[i].type == MBR_EXT_LBA) { - // Go to the EBR next - next_sector = this_sector + partentry[i].lbaFirst; - } - } - } while (next_sector != 0 && num_parts < MAX_PARTITIONS); - - return 0; -} - -static void usage() -{ - printf("Usage: chud X:, where X is a drive letter handled by CHUDISK.SYS\n"); -} - -int main(int argc, const char *argv[]) -{ - static char buffer[16]; - int i; - unsigned part; - - for (i = 1; i < argc; i++) { - // Drive letter? - if (argv[i][0] >= 'A' && argv[i][0] <= 'Z' && argv[i][1] == ':') { - drive = 1 + argv[i][0] - 'A'; - } else if (argv[i][0] >= 'a' && argv[i][0] <= 'z' && argv[i][1] == ':') { - drive = 1 + argv[i][0] - 'a'; - } - } - - // Now read the driver settings and current partition - i = ioctl_read_control(drive, buffer, sizeof(buffer)); - if (i < 0) { - perror("ioctl_read_control"); - usage(); - return EXIT_FAILURE; - } - - if (parse_chudisk_control_string(buffer, i)) { - fprintf(stderr, "wrong IOCTL string returned by driver\n"); - usage(); - return EXIT_FAILURE; - } - - if (scan_disk_partitions() != 0) { - return EXIT_FAILURE; - } - if (num_parts == 0) { - fprintf(stderr, "No partitions found on the disk\n"); - return EXIT_FAILURE; - } - - printf("Select partition in [1..%u] range: ", num_parts); - i = scanf("%u", &part); - - if (i != 1) { - // Assume cancel - return EXIT_FAILURE; - } - - if (part == 0 || part > num_parts) { - fprintf(stderr, "Invalid partition %u\n", part); - return EXIT_FAILURE; - } - - printf("Switching drive to partition %u at offset %lu size %lu\n", part, - partinfo[part-1].start_sector, partinfo[part-1].num_sectors); - - dos_disk_reset(); // Flush caches before we swap the drive... - - i = 0; - buffer[i++] = 'S'; - memcpy(&buffer[i], &partinfo[part-1].start_sector, sizeof(uint32_t)); - i+=sizeof(uint32_t); - buffer[i++] = 'L'; - memcpy(&buffer[i], &partinfo[part-1].num_sectors, sizeof(uint32_t)); - i+=sizeof(uint32_t); - buffer[i] = '\0'; - - if (ioctl_write_control(drive, buffer, i) < i) { - perror("ioctl_write_control"); - return EXIT_FAILURE; - } - - // The above IOCTL will also cause the next mediacheck from DOS to return changed. - - return EXIT_SUCCESS; -} |