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Kevin O'Connora3855ad2009-08-16 21:59:40 -04001// Code for emulating a drive via high-memory accesses.
2//
3// Copyright (C) 2009 Kevin O'Connor <kevin@koconnor.net>
4//
5// This file may be distributed under the terms of the GNU LGPLv3 license.
6
7#include "disk.h" // process_ramdisk_op
8#include "util.h" // dprintf
9#include "memmap.h" // add_e820
10#include "biosvar.h" // GET_GLOBAL
11#include "bregs.h" // struct bregs
Kevin O'Connorca2bc1c2010-12-29 21:41:19 -050012#include "boot.h" // boot_add_floppy
Kevin O'Connor3df600b2013-09-14 19:28:55 -040013#include "stacks.h" // call16_int
Kevin O'Connorfa9c66a2013-09-14 19:10:40 -040014#include "string.h" // memset
Kevin O'Connora3855ad2009-08-16 21:59:40 -040015
Kevin O'Connora3855ad2009-08-16 21:59:40 -040016void
Kevin O'Connor1ca05b02010-01-03 17:43:37 -050017ramdisk_setup(void)
Kevin O'Connora3855ad2009-08-16 21:59:40 -040018{
Kevin O'Connor59d6ca52012-05-31 00:20:55 -040019 if (!CONFIG_FLASH_FLOPPY)
Kevin O'Connora3855ad2009-08-16 21:59:40 -040020 return;
21
22 // Find image.
Kevin O'Connor59d6ca52012-05-31 00:20:55 -040023 struct romfile_s *file = romfile_findprefix("floppyimg/", NULL);
Kevin O'Connora3855ad2009-08-16 21:59:40 -040024 if (!file)
25 return;
Kevin O'Connor59d6ca52012-05-31 00:20:55 -040026 const char *filename = file->name;
27 u32 size = file->size;
Kevin O'Connorc4bd3b92010-12-29 21:59:44 -050028 dprintf(3, "Found floppy file %s of size %d\n", filename, size);
Kevin O'Connora3855ad2009-08-16 21:59:40 -040029 int ftype = find_floppy_type(size);
30 if (ftype < 0) {
31 dprintf(3, "No floppy type found for ramdisk size\n");
32 return;
33 }
34
35 // Allocate ram for image.
Kevin O'Connor907a41c2009-08-30 19:31:22 -040036 void *pos = memalign_tmphigh(PAGE_SIZE, size);
37 if (!pos) {
Kevin O'Connorcfdc13f2010-02-14 13:07:54 -050038 warn_noalloc();
Kevin O'Connora3855ad2009-08-16 21:59:40 -040039 return;
40 }
Kevin O'Connor907a41c2009-08-30 19:31:22 -040041 add_e820((u32)pos, size, E820_RESERVED);
Kevin O'Connora3855ad2009-08-16 21:59:40 -040042
43 // Copy image into ram.
Kevin O'Connor59d6ca52012-05-31 00:20:55 -040044 int ret = file->copy(file, pos, size);
45 if (ret < 0)
46 return;
Kevin O'Connora3855ad2009-08-16 21:59:40 -040047
48 // Setup driver.
Kevin O'Connorca2bc1c2010-12-29 21:41:19 -050049 struct drive_s *drive_g = init_floppy((u32)pos, ftype);
Kevin O'Connor575ffc82010-02-21 23:20:10 -050050 if (!drive_g)
Kevin O'Connorca2bc1c2010-12-29 21:41:19 -050051 return;
52 drive_g->type = DTYPE_RAMDISK;
Kevin O'Connorc4bd3b92010-12-29 21:59:44 -050053 dprintf(1, "Mapping CBFS floppy %s to addr %p\n", filename, pos);
54 char *desc = znprintf(MAXDESCSIZE, "Ramdisk [%s]", &filename[10]);
55 boot_add_floppy(drive_g, desc, bootprio_find_named_rom(filename, 0));
Kevin O'Connora3855ad2009-08-16 21:59:40 -040056}
57
58static int
Kevin O'Connor907a41c2009-08-30 19:31:22 -040059ramdisk_copy(struct disk_op_s *op, int iswrite)
Kevin O'Connora3855ad2009-08-16 21:59:40 -040060{
Kevin O'Connor77d227b2009-10-22 21:48:39 -040061 u32 offset = GET_GLOBAL(op->drive_g->cntl_id);
Kevin O'Connor36c93a52009-09-12 19:35:04 -040062 offset += (u32)op->lba * DISK_SECTOR_SIZE;
Kevin O'Connora3855ad2009-08-16 21:59:40 -040063 u64 opd = GDT_DATA | GDT_LIMIT(0xfffff) | GDT_BASE((u32)op->buf_fl);
64 u64 ramd = GDT_DATA | GDT_LIMIT(0xfffff) | GDT_BASE(offset);
65
66 u64 gdt[6];
67 if (iswrite) {
68 gdt[2] = opd;
69 gdt[3] = ramd;
70 } else {
71 gdt[2] = ramd;
72 gdt[3] = opd;
73 }
74
Kevin O'Connor907a41c2009-08-30 19:31:22 -040075 // Call int 1587 to copy data.
Kevin O'Connora3855ad2009-08-16 21:59:40 -040076 struct bregs br;
77 memset(&br, 0, sizeof(br));
Kevin O'Connorf8e800d2009-09-24 21:01:16 -040078 br.flags = F_CF|F_IF;
Kevin O'Connora3855ad2009-08-16 21:59:40 -040079 br.ah = 0x87;
80 br.es = GET_SEG(SS);
81 br.si = (u32)gdt;
Kevin O'Connor36c93a52009-09-12 19:35:04 -040082 br.cx = op->count * DISK_SECTOR_SIZE / 2;
Kevin O'Connora3855ad2009-08-16 21:59:40 -040083 call16_int(0x15, &br);
84
Kevin O'Connor907a41c2009-08-30 19:31:22 -040085 if (br.flags & F_CF)
86 return DISK_RET_EBADTRACK;
Kevin O'Connora3855ad2009-08-16 21:59:40 -040087 return DISK_RET_SUCCESS;
88}
89
90int
91process_ramdisk_op(struct disk_op_s *op)
92{
Kevin O'Connor897fb112013-02-07 23:32:48 -050093 if (!CONFIG_FLASH_FLOPPY)
Kevin O'Connora3855ad2009-08-16 21:59:40 -040094 return 0;
95
96 switch (op->command) {
97 case CMD_READ:
Kevin O'Connor907a41c2009-08-30 19:31:22 -040098 return ramdisk_copy(op, 0);
Kevin O'Connora3855ad2009-08-16 21:59:40 -040099 case CMD_WRITE:
Kevin O'Connor907a41c2009-08-30 19:31:22 -0400100 return ramdisk_copy(op, 1);
Kevin O'Connora3855ad2009-08-16 21:59:40 -0400101 case CMD_VERIFY:
102 case CMD_FORMAT:
103 case CMD_RESET:
104 return DISK_RET_SUCCESS;
105 default:
106 op->count = 0;
107 return DISK_RET_EPARAM;
108 }
109}