1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
|
#include "types.h"
#include "Process.h"
#include "VGA.h"
#include "Disk.h"
#include "kmalloc.h"
#include "StdLib.h"
#include "IO.h"
#include "i386.h"
#include "PIC.h"
//#define DISK_DEBUG
extern "C" void handle_interrupt();
namespace Disk {
ide_drive_t drive[4];
static volatile bool interrupted;
#define IRQ_FIXED_DISK 14
extern "C" void ide_ISR();
asm(
".globl ide_ISR \n"
"ide_ISR: \n"
" pusha\n"
" pushw %ds\n"
" pushw %es\n"
" pushw %ss\n"
" pushw %ss\n"
" popw %ds\n"
" popw %es\n"
" call handle_interrupt\n"
" popw %es\n"
" popw %ds\n"
" popa\n"
" iret\n"
);
static void enableIRQ()
{
PIC::enable(IRQ_FIXED_DISK);
}
static void disableIRQ()
{
PIC::disable(IRQ_FIXED_DISK);
}
static bool waitForInterrupt()
{
#ifdef DISK_DEBUG
kprintf("disk: waiting for interrupt...\n");
#endif
// FIXME: Add timeout.
while (!interrupted) {
yield();
}
#ifdef DISK_DEBUG
kprintf("disk: got interrupt!\n");
#endif
return true;
}
void interrupt()
{
IRQHandlerScope scope(IRQ_FIXED_DISK);
#ifdef DISK_DEBUG
BYTE status = IO::in8(0x1f7);
kprintf("disk:interrupt: DRQ=%u BUSY=%u DRDY=%u\n", (status & DRQ) != 0, (status & BUSY) != 0, (status & DRDY) != 0);
#endif
interrupted = true;
}
static SpinLock* s_diskLock;
void initialize()
{
s_diskLock = new SpinLock;
disableIRQ();
interrupted = false;
registerInterruptHandler(IRQ_VECTOR_BASE + IRQ_FIXED_DISK, ide_ISR);
while (IO::in8(IDE0_STATUS) & BUSY);
IO::out8(0x1F6, 0xA0); // 0xB0 for 2nd device
IO::out8(IDE0_COMMAND, IDENTIFY_DRIVE);
enableIRQ();
waitForInterrupt();
ByteBuffer wbuf = ByteBuffer::createUninitialized(512);
ByteBuffer bbuf = ByteBuffer::createUninitialized(512);
BYTE* b = bbuf.pointer();
WORD* w = (WORD*)wbuf.pointer();
const WORD* wbufbase = (WORD*)wbuf.pointer();
for (DWORD i = 0; i < 256; ++i) {
WORD data = IO::in16(IDE0_DATA);
*(w++) = data;
*(b++) = MSB(data);
*(b++) = LSB(data);
}
// "Unpad" the device name string.
for (DWORD i = 93; i > 54 && bbuf[i] == ' '; --i)
bbuf[i] = 0;
drive[0].cylinders = wbufbase[1];
drive[0].heads = wbufbase[3];
drive[0].sectors_per_track = wbufbase[6];
kprintf(
"ide0: Master=\"%s\", C/H/Spt=%u/%u/%u\n",
bbuf.pointer() + 54,
drive[0].cylinders,
drive[0].heads,
drive[0].sectors_per_track
);
}
struct CHS {
DWORD cylinder;
WORD head;
WORD sector;
};
static CHS lba2chs(BYTE drive_index, DWORD lba)
{
ide_drive_t& d = drive[drive_index];
CHS chs;
chs.cylinder = lba / (d.sectors_per_track * d.heads);
chs.head = (lba / d.sectors_per_track) % d.heads;
chs.sector = (lba % d.sectors_per_track) + 1;
return chs;
}
bool readSectors(DWORD startSector, WORD count, BYTE* outbuf)
{
LOCKER(*s_diskLock);
#ifdef DISK_DEBUG
kprintf("%s: Disk::readSectors request (%u sector(s) @ %u)\n",
current->name().characters(),
count,
startSector);
#endif
disableIRQ();
CHS chs = lba2chs(IDE0_DISK0, startSector);
while (IO::in8(IDE0_STATUS) & BUSY);
#ifdef DISK_DEBUG
kprintf("ide0: Reading %u sector(s) @ LBA %u (%u/%u/%u)\n", count, startSector, chs.cylinder, chs.head, chs.sector);
#endif
IO::out8(0x1F2, count == 256 ? 0 : LSB(count));
IO::out8(0x1F3, chs.sector);
IO::out8(0x1F4, LSB(chs.cylinder));
IO::out8(0x1F5, MSB(chs.cylinder));
IO::out8(0x1F6, 0xA0 | chs.head); /* 0xB0 for 2nd device */
IO::out8(0x3F6, 0x08);
while (!(IO::in8(IDE0_STATUS) & DRDY));
IO::out8(IDE0_COMMAND, READ_SECTORS);
interrupted = false;
enableIRQ();
waitForInterrupt();
BYTE status = IO::in8(0x1f7);
if (status & DRQ) {
#ifdef DISK_DEBUG
kprintf("Retrieving %u bytes (status=%b), outbuf=%p...\n", count * 512, status, outbuf);
#endif
for (DWORD i = 0; i < (count * 512); i += 2) {
WORD w = IO::in16(IDE0_DATA);
outbuf[i] = LSB(w);
outbuf[i+1] = MSB(w);
}
}
return true;
}
}
extern "C" void handle_interrupt()
{
Disk::interrupt();
}
|
