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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'Connor41639f82013-09-14 19:37:36 -040013#include "romfile.h" // romfile_findprefix
Kevin O'Connor3df600b2013-09-14 19:28:55 -040014#include "stacks.h" // call16_int
Kevin O'Connorfa9c66a2013-09-14 19:10:40 -040015#include "string.h" // memset
Kevin O'Connora3855ad2009-08-16 21:59:40 -040016
Kevin O'Connora3855ad2009-08-16 21:59:40 -040017void
Kevin O'Connor1ca05b02010-01-03 17:43:37 -050018ramdisk_setup(void)
Kevin O'Connora3855ad2009-08-16 21:59:40 -040019{
Kevin O'Connor59d6ca52012-05-31 00:20:55 -040020 if (!CONFIG_FLASH_FLOPPY)
Kevin O'Connora3855ad2009-08-16 21:59:40 -040021 return;
22
23 // Find image.
Kevin O'Connor59d6ca52012-05-31 00:20:55 -040024 struct romfile_s *file = romfile_findprefix("floppyimg/", NULL);
Kevin O'Connora3855ad2009-08-16 21:59:40 -040025 if (!file)
26 return;
Kevin O'Connor59d6ca52012-05-31 00:20:55 -040027 const char *filename = file->name;
28 u32 size = file->size;
Kevin O'Connorc4bd3b92010-12-29 21:59:44 -050029 dprintf(3, "Found floppy file %s of size %d\n", filename, size);
Kevin O'Connora3855ad2009-08-16 21:59:40 -040030 int ftype = find_floppy_type(size);
31 if (ftype < 0) {
32 dprintf(3, "No floppy type found for ramdisk size\n");
33 return;
34 }
35
36 // Allocate ram for image.
Kevin O'Connor907a41c2009-08-30 19:31:22 -040037 void *pos = memalign_tmphigh(PAGE_SIZE, size);
38 if (!pos) {
Kevin O'Connorcfdc13f2010-02-14 13:07:54 -050039 warn_noalloc();
Kevin O'Connora3855ad2009-08-16 21:59:40 -040040 return;
41 }
Kevin O'Connor907a41c2009-08-30 19:31:22 -040042 add_e820((u32)pos, size, E820_RESERVED);
Kevin O'Connora3855ad2009-08-16 21:59:40 -040043
44 // Copy image into ram.
Kevin O'Connor59d6ca52012-05-31 00:20:55 -040045 int ret = file->copy(file, pos, size);
46 if (ret < 0)
47 return;
Kevin O'Connora3855ad2009-08-16 21:59:40 -040048
49 // Setup driver.
Kevin O'Connorca2bc1c2010-12-29 21:41:19 -050050 struct drive_s *drive_g = init_floppy((u32)pos, ftype);
Kevin O'Connor575ffc82010-02-21 23:20:10 -050051 if (!drive_g)
Kevin O'Connorca2bc1c2010-12-29 21:41:19 -050052 return;
53 drive_g->type = DTYPE_RAMDISK;
Kevin O'Connorc4bd3b92010-12-29 21:59:44 -050054 dprintf(1, "Mapping CBFS floppy %s to addr %p\n", filename, pos);
55 char *desc = znprintf(MAXDESCSIZE, "Ramdisk [%s]", &filename[10]);
56 boot_add_floppy(drive_g, desc, bootprio_find_named_rom(filename, 0));
Kevin O'Connora3855ad2009-08-16 21:59:40 -040057}
58
59static int
Kevin O'Connor907a41c2009-08-30 19:31:22 -040060ramdisk_copy(struct disk_op_s *op, int iswrite)
Kevin O'Connora3855ad2009-08-16 21:59:40 -040061{
Kevin O'Connor77d227b2009-10-22 21:48:39 -040062 u32 offset = GET_GLOBAL(op->drive_g->cntl_id);
Kevin O'Connor36c93a52009-09-12 19:35:04 -040063 offset += (u32)op->lba * DISK_SECTOR_SIZE;
Kevin O'Connora3855ad2009-08-16 21:59:40 -040064 u64 opd = GDT_DATA | GDT_LIMIT(0xfffff) | GDT_BASE((u32)op->buf_fl);
65 u64 ramd = GDT_DATA | GDT_LIMIT(0xfffff) | GDT_BASE(offset);
66
67 u64 gdt[6];
68 if (iswrite) {
69 gdt[2] = opd;
70 gdt[3] = ramd;
71 } else {
72 gdt[2] = ramd;
73 gdt[3] = opd;
74 }
75
Kevin O'Connor907a41c2009-08-30 19:31:22 -040076 // Call int 1587 to copy data.
Kevin O'Connora3855ad2009-08-16 21:59:40 -040077 struct bregs br;
78 memset(&br, 0, sizeof(br));
Kevin O'Connorf8e800d2009-09-24 21:01:16 -040079 br.flags = F_CF|F_IF;
Kevin O'Connora3855ad2009-08-16 21:59:40 -040080 br.ah = 0x87;
81 br.es = GET_SEG(SS);
82 br.si = (u32)gdt;
Kevin O'Connor36c93a52009-09-12 19:35:04 -040083 br.cx = op->count * DISK_SECTOR_SIZE / 2;
Kevin O'Connora3855ad2009-08-16 21:59:40 -040084 call16_int(0x15, &br);
85
Kevin O'Connor907a41c2009-08-30 19:31:22 -040086 if (br.flags & F_CF)
87 return DISK_RET_EBADTRACK;
Kevin O'Connora3855ad2009-08-16 21:59:40 -040088 return DISK_RET_SUCCESS;
89}
90
91int
92process_ramdisk_op(struct disk_op_s *op)
93{
Kevin O'Connor897fb112013-02-07 23:32:48 -050094 if (!CONFIG_FLASH_FLOPPY)
Kevin O'Connora3855ad2009-08-16 21:59:40 -040095 return 0;
96
97 switch (op->command) {
98 case CMD_READ:
Kevin O'Connor907a41c2009-08-30 19:31:22 -040099 return ramdisk_copy(op, 0);
Kevin O'Connora3855ad2009-08-16 21:59:40 -0400100 case CMD_WRITE:
Kevin O'Connor907a41c2009-08-30 19:31:22 -0400101 return ramdisk_copy(op, 1);
Kevin O'Connora3855ad2009-08-16 21:59:40 -0400102 case CMD_VERIFY:
103 case CMD_FORMAT:
104 case CMD_RESET:
105 return DISK_RET_SUCCESS;
106 default:
107 op->count = 0;
108 return DISK_RET_EPARAM;
109 }
110}