| // Code for emulating a drive via high-memory accesses. |
| // |
| // Copyright (C) 2009 Kevin O'Connor <kevin@koconnor.net> |
| // |
| // This file may be distributed under the terms of the GNU LGPLv3 license. |
| |
| #include "disk.h" // process_ramdisk_op |
| #include "util.h" // dprintf |
| #include "memmap.h" // add_e820 |
| #include "biosvar.h" // GET_GLOBAL |
| #include "bregs.h" // struct bregs |
| #include "boot.h" // boot_add_floppy |
| |
| void |
| ramdisk_setup(void) |
| { |
| if (!CONFIG_FLASH_FLOPPY) |
| return; |
| |
| // Find image. |
| struct romfile_s *file = romfile_findprefix("floppyimg/", NULL); |
| if (!file) |
| return; |
| const char *filename = file->name; |
| u32 size = file->size; |
| dprintf(3, "Found floppy file %s of size %d\n", filename, size); |
| int ftype = find_floppy_type(size); |
| if (ftype < 0) { |
| dprintf(3, "No floppy type found for ramdisk size\n"); |
| return; |
| } |
| |
| // Allocate ram for image. |
| void *pos = memalign_tmphigh(PAGE_SIZE, size); |
| if (!pos) { |
| warn_noalloc(); |
| return; |
| } |
| add_e820((u32)pos, size, E820_RESERVED); |
| |
| // Copy image into ram. |
| int ret = file->copy(file, pos, size); |
| if (ret < 0) |
| return; |
| |
| // Setup driver. |
| struct drive_s *drive_g = init_floppy((u32)pos, ftype); |
| if (!drive_g) |
| return; |
| drive_g->type = DTYPE_RAMDISK; |
| dprintf(1, "Mapping CBFS floppy %s to addr %p\n", filename, pos); |
| char *desc = znprintf(MAXDESCSIZE, "Ramdisk [%s]", &filename[10]); |
| boot_add_floppy(drive_g, desc, bootprio_find_named_rom(filename, 0)); |
| } |
| |
| static int |
| ramdisk_copy(struct disk_op_s *op, int iswrite) |
| { |
| u32 offset = GET_GLOBAL(op->drive_g->cntl_id); |
| offset += (u32)op->lba * DISK_SECTOR_SIZE; |
| u64 opd = GDT_DATA | GDT_LIMIT(0xfffff) | GDT_BASE((u32)op->buf_fl); |
| u64 ramd = GDT_DATA | GDT_LIMIT(0xfffff) | GDT_BASE(offset); |
| |
| u64 gdt[6]; |
| if (iswrite) { |
| gdt[2] = opd; |
| gdt[3] = ramd; |
| } else { |
| gdt[2] = ramd; |
| gdt[3] = opd; |
| } |
| |
| // Call int 1587 to copy data. |
| struct bregs br; |
| memset(&br, 0, sizeof(br)); |
| br.flags = F_CF|F_IF; |
| br.ah = 0x87; |
| br.es = GET_SEG(SS); |
| br.si = (u32)gdt; |
| br.cx = op->count * DISK_SECTOR_SIZE / 2; |
| call16_int(0x15, &br); |
| |
| if (br.flags & F_CF) |
| return DISK_RET_EBADTRACK; |
| return DISK_RET_SUCCESS; |
| } |
| |
| int |
| process_ramdisk_op(struct disk_op_s *op) |
| { |
| if (!CONFIG_FLASH_FLOPPY) |
| return 0; |
| |
| switch (op->command) { |
| case CMD_READ: |
| return ramdisk_copy(op, 0); |
| case CMD_WRITE: |
| return ramdisk_copy(op, 1); |
| case CMD_VERIFY: |
| case CMD_FORMAT: |
| case CMD_RESET: |
| return DISK_RET_SUCCESS; |
| default: |
| op->count = 0; |
| return DISK_RET_EPARAM; |
| } |
| } |