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
194
195
196
197
|
use errors;
use io;
use types;
use rt;
use fmt;
use mbr;
use sector;
export type nogpt = !void;
export type gpt = struct {
mbr_sec: sector::sector,
mbr: *mbr::mbr,
primary: block,
backup: block
};
export type block = struct {
header_sec: sector::sector,
entries_sec: sector::sector,
header: *header,
entries: *[128]entry
};
fn block_getheader(self: *block) *header = {
return self.header_sec.buf: *[*]u8: *header;
};
fn block_getentries(self: *block) []entry = {
const e = types::slice {
data = self.entries_sec.buf: *[*]u8,
length = 128,
capacity = 128
};
return *(&e: *const []entry);
};
fn block_commit(self: *block) void = {
sector::commit(&self.header_sec);
//sector::commit(&self.entries_sec);
};
fn block_fetch(self: *block) void = {
sector::fetch(&self.header_sec);
sector::fetch(&self.entries_sec);
};
fn block_drop(self: *block) void = {
sector::finish(&self.header_sec);
sector::finish(&self.entries_sec);
};
export type header = struct {
@offset(0) signature: u64,
@offset(8) revision: u32,
@offset(12) header_size: u32,
@offset(16) header_crc32: u32,
@offset(20) reserved0: u32,
@offset(24) header_lba: u64,
@offset(32) backup_header_lba: u64,
@offset(40) first_lba: u64,
@offset(48) last_lba: u64,
@offset(56) disk_guid: [2]u64,
@offset(72) entries_lba: u64,
@offset(80) entries_len: u32,
@offset(84) entry_size: u32,
@offset(88) entries_crc32: u32
};
export type entry = struct {
@offset(0) part_type: [2]u64,
@offset(16) part: [2]u64,
@offset(32) lba_begin: u64,
@offset(40) lba_end: u64,
@offset(48) attributes: u64,
@offset(56) name: [72]u8
};
export fn validate(self: *gpt) bool = {
if (getheader(self).signature != 0x5452415020494645) {
return false;
};
return true;
};
export fn from(fd: io::file) (*gpt | nogpt | errors::error) = {
const prim_header_sector = sector::map(fd, 1, 1);
sector::fetch(&prim_header_sector);
const prim_header = prim_header_sector.buf: *[*]u8: *header;
// XXX validate header
const prim_table_sector = sector::map(fd, prim_header.entries_lba, prim_header.entries_lba + 128*128/512 - 1);
sector::fetch(&prim_table_sector);
// Create the primary GPT copy
const primary = block {
header_sec = prim_header_sector,
entries_sec = prim_table_sector,
header = prim_header,
entries = prim_table_sector.buf: *[*]u8: *[128]entry
};
const back_header_sector = sector::map(fd, prim_header.backup_header_lba, prim_header.backup_header_lba);
sector::fetch(&back_header_sector);
const back_header = back_header_sector.buf: *[*]u8: *header;
//XXX validate header
const back_table_sector = sector::map(fd, back_header.entries_lba, back_header.entries_lba + 128*128/512 - 1);
sector::fetch(&back_table_sector);
// Create the backup block structure
let backup = block {
header_sec = back_header_sector,
entries_sec = back_table_sector,
header = back_header,
entries = back_table_sector.buf: *[*]u8: *[128]entry
};
const mbr_sec = sector::map(fd, 0, 0);
// Allocate the GPT structure
let self = alloc(gpt {
mbr_sec = mbr_sec,
mbr = mbr_sec.buf: *[*]u8: *mbr::mbr,
primary = primary,
backup = backup
});
// Fetch the MBR
sector::fetch(&self.mbr_sec);
return self;
};
// Frees the resources associated with the GPT structure.
export fn finish(self: *gpt) void = {
sector::finish(&self.mbr_sec);
block_drop(&self.primary);
block_drop(&self.backup);
free(self);
};
// Updates the data structures from the disk
export fn fetch(self: *gpt) void = {
sector::fetch(&self.mbr_sec);
block_fetch(&self.primary);
block_fetch(&self.backup);
};
export fn mkbackup(self: *gpt) void = {
rt::memcpy(self.backup.header, self.primary.header, size(header));
rt::memcpy(self.backup.entries, self.primary.entries, size([128]entry));
self.backup.header.header_lba = self.backup.header_sec.lba_begin;
self.backup.header.backup_header_lba = self.primary.header_sec.lba_begin;
self.backup.header.entries_lba = self.backup.entries_sec.lba_begin;
};
// Commits changed done on the data structure to the disk
export fn commit(self: *gpt) void = {
// XXX: CRC32 checksum
sector::commit(&self.mbr_sec);
block_commit(&self.primary);
block_commit(&self.backup);
//const header = getheader(self);
// XXX: update copy
//sector::commit_at(self.mbr, self.mbr.fd, header.backup_header_lba);
};
// Updates the CRC32 checksums of the different blocks
export fn chksums(self: *gpt) void = {
self.primary.header.header_crc32 = header_crc32(self.primary.header);
self.backup.header.header_crc32 = header_crc32(self.backup.header);
};
// Gets the MBR structure. Return value is borrowed from argument.
export fn getmbr(self: *gpt) *mbr::mbr = {
return self.mbr_sec.buf: *[*]u8: *mbr::mbr;
};
// Gets the GPT primary header structure. Return value is borrowed from argument.
export fn getheader(self: *gpt) *header = {
return block_getheader(&self.primary);
};
// Gets the GPT primary entries structures. Return value is borrowed from argument.
export fn getentries(self: *gpt) []entry = {
return block_getentries(&self.primary);
};
|
