-
Notifications
You must be signed in to change notification settings - Fork 0
/
Copy pathmisc_tools.asm
350 lines (295 loc) · 8.14 KB
/
misc_tools.asm
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
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
;all this stuff is in 32bit assembly so don't put any real mode specific stuff in here
[BITS 32]
[CPU 486]
section .auxfunctions
;sets IOPL to 3 regardless of anything else
global forceIOPL_High
forceIOPL_High:
pushf
pop eax
or eax, 0x3000
push eax
popf
ret
;sets IOPL to 0 regardless of anything else
global forceIOPL_Low
forceIOPL_Low:
pushf
pop eax
and eax, 0xCFFF
push eax
popf
ret
;here's my real mode x86 keyboard stuff. I see no reason why it wouldn't work here tbh
global waitAck
waitAck:
call kbd8042WaitReadReady
in al, 060h
cmp al, 0FAh
jne waitAck
ret
global kbd8042WaitReadReady
kbd8042WaitReadReady:
in al, 064h ;8042 status port
and al, 00000001b ;read the data register read ready bit
cmp al, 1
jne kbd8042WaitReadReady ;if it's not ready, keep waiting until it is
ret
global kbd8042WaitWriteReady
kbd8042WaitWriteReady:
in al, 064h
and al, 00000010b
ror al, 1
cmp al, 0
jne kbd8042WaitWriteReady
ret
;do note that changing compilers may make these stop working because of calling conventions and all
;char byte, unsigned int port
global asmOutb
asmOutb:
push ebp
mov ebp, esp
mov edx, [ebp+12]
mov eax, [ebp+8]
out dx, al
leave
ret
;unsigned int port
global asmInb
asmInb:
push ebp
mov ebp, esp
mov edx, [ebp+8]
mov eax, 0
in al, dx
leave
ret
;;the same thing but for 16 bit transfers
global asmOutW
asmOutW:
push ebp
mov ebp, esp
mov edx, [ebp+12]
mov eax, [ebp+8]
out dx, ax
leave
ret
global asmInW
asmInW:
push ebp
mov ebp, esp
mov edx, [ebp+8]
mov eax, 0
in ax, dx
leave
ret
;cpuid command. get information about the cpu and then return it
global cpu_ident
cpu_ident:
push ebp
mov ebp, esp
CPU 586
mov eax, 0x01
cpuid
CPU 486
;info we want is in the eax register
leave
ret
;get the cpu vendor
global cpu_vendor
cpu_vendor:
push ebp
mov ebp, esp
CPU 586
mov eax, 0
cpuid
CPU 486
;good enough
mov eax, ebx
leave
ret
global enable_A20
enable_A20:
;cli
call a20wait
mov al,0xAD
out 0x64,al
call a20wait
mov al,0xD0
out 0x64,al
call a20wait2
in al,0x60
push eax
call a20wait
mov al,0xD1
out 0x64,al
call a20wait
pop eax
or al,2
out 0x60,al
call a20wait
mov al,0xAE
out 0x64,al
call a20wait
;sti
ret
a20wait:
in al,0x64
test al,2
jnz a20wait
ret
a20wait2:
in al,0x64
test al,1
jz a20wait2
ret
;a really basic way to move an error message to a location in memory so that it can be read with a debugger
generic_error:
mov al, 'F'
mov ah, 0x04
mov [0xB8936], ax
mov al, 'U'
mov ah, 0x04
mov [0xB8938], ax
mov al, 'C'
mov ah, 0x04
mov [0xB893A], ax
mov al, 'K'
mov ah, 0x04
mov [0xB893C], ax
hlt
ret
;drop into real mode and jump to the 1mb ram boundary. Takes no inputs because i'm not going to spend an entire afternoon trial and erroring stack calling conventions until it works
bootFromHighMem:
ret
;trigger interrupt 3 and hopefully trigger an arbitrary breakpoint
global insert_breakpoint_asm
insert_breakpoint_asm:
push ebp
mov ebp, esp
int 3
leave
ret
Invalid_TSS:
ret
;sets up the ldt and then fucks off
setupldt:
;put address of error subroutine
mov eax, generic_error
mov [Invalid_TSS_INT], ax
mov cl, 16
sar eax, cl
mov [Invalid_TSS_INT+6], ax
lidt [top_idt] ;load gdt settings
ret
;Now for the idt
;you need interrupts to work since exceptions are interrupts
idt:
dq 0x00
Invalid_TSS_INT:
;each entry is 64 bits (damn lol what a pain)
dw 0x00 ;offset bits 0-15
dw 0x10 ;segment selector 16 bits
dw 0xEE00 ;bits32-39 reserved. bits 40-43 gate type. bit 45-46 dpl. bit 47 present bit
dw 0x00 ;offset bits 16-31
Invalid_TSS_INT1:
;each entry is 64 bits (damn lol what a pain)
dw 0x00 ;offset bits 0-15
dw 0x10 ;segment selector 16 bits
dw 0xEE00 ;bits32-39 reserved. bits 40-43 gate type. bit 45-46 dpl. bit 47 present bit
dw 0x00 ;offset bits 16-31
Invalid_TSS_INT2:
;each entry is 64 bits (damn lol what a pain)
dw 0x00 ;offset bits 0-15
dw 0x10 ;segment selector 16 bits
dw 0xEE00 ;bits32-39 reserved. bits 40-43 gate type. bit 45-46 dpl. bit 47 present bit
dw 0x00 ;offset bits 16-31
Invalid_TSS_INT3:
;each entry is 64 bits (damn lol what a pain)
dw 0x00 ;offset bits 0-15
dw 0x10 ;segment selector 16 bits
dw 0xEE00 ;bits32-39 reserved. bits 40-43 gate type. bit 45-46 dpl. bit 47 present bit
dw 0x00 ;offset bits 16-31
Invalid_TSS_INT4:
;each entry is 64 bits (damn lol what a pain)
dw 0x00 ;offset bits 0-15
dw 0x10 ;segment selector 16 bits
dw 0xEE00 ;bits32-39 reserved. bits 40-43 gate type. bit 45-46 dpl. bit 47 present bit
dw 0x00 ;offset bits 16-31
Invalid_TSS_INT5:
;each entry is 64 bits (damn lol what a pain)
dw 0x00 ;offset bits 0-15
dw 0x10 ;segment selector 16 bits
dw 0xEE00 ;bits32-39 reserved. bits 40-43 gate type. bit 45-46 dpl. bit 47 present bit
dw 0x00 ;offset bits 16-31
Invalid_TSS_INT6:
;each entry is 64 bits (damn lol what a pain)
dw 0x00 ;offset bits 0-15
dw 0x10 ;segment selector 16 bits
dw 0xEE00 ;bits32-39 reserved. bits 40-43 gate type. bit 45-46 dpl. bit 47 present bit
dw 0x00 ;offset bits 16-31
Invalid_TSS_INT7:
;each entry is 64 bits (damn lol what a pain)
dw 0x00 ;offset bits 0-15
dw 0x10 ;segment selector 16 bits
dw 0xEE00 ;bits32-39 reserved. bits 40-43 gate type. bit 45-46 dpl. bit 47 present bit
dw 0x00 ;offset bits 16-31
Invalid_TSS_INT8:
;each entry is 64 bits (damn lol what a pain)
dw 0x00 ;offset bits 0-15
dw 0x10 ;segment selector 16 bits
dw 0xEE00 ;bits32-39 reserved. bits 40-43 gate type. bit 45-46 dpl. bit 47 present bit
dw 0x00 ;offset bits 16-31
Invalid_TSS_INT9:
;each entry is 64 bits (damn lol what a pain)
dw 0x00 ;offset bits 0-15
dw 0x10 ;segment selector 16 bits
dw 0xEE00 ;bits32-39 reserved. bits 40-43 gate type. bit 45-46 dpl. bit 47 present bit
dw 0x00 ;offset bits 16-31
Invalid_TSS_INT10:
;each entry is 64 bits (damn lol what a pain)
dw 0x00 ;offset bits 0-15
dw 0x10 ;segment selector 16 bits
dw 0xEE00 ;bits32-39 reserved. bits 40-43 gate type. bit 45-46 dpl. bit 47 present bit
dw 0x00 ;offset bits 16-31
Invalid_TSS_INT11:
;each entry is 64 bits (damn lol what a pain)
dw 0x00 ;offset bits 0-15
dw 0x10 ;segment selector 16 bits
dw 0xEE00 ;bits32-39 reserved. bits 40-43 gate type. bit 45-46 dpl. bit 47 present bit
dw 0x00 ;offset bits 16-31
Invalid_TSS_INT12:
;each entry is 64 bits (damn lol what a pain)
dw 0x00 ;offset bits 0-15
dw 0x10 ;segment selector 16 bits
dw 0xEE00 ;bits32-39 reserved. bits 40-43 gate type. bit 45-46 dpl. bit 47 present bit
dw 0x00 ;offset bits 16-31
Invalid_TSS_INT13:
;each entry is 64 bits (damn lol what a pain)
dw 0x00 ;offset bits 0-15
dw 0x10 ;segment selector 16 bits
dw 0xEE00 ;bits32-39 reserved. bits 40-43 gate type. bit 45-46 dpl. bit 47 present bit
dw 0x00 ;offset bits 16-31
Invalid_TSS_INT14:
;each entry is 64 bits (damn lol what a pain)
dw 0x00 ;offset bits 0-15
dw 0x10 ;segment selector 16 bits
dw 0xEE00 ;bits32-39 reserved. bits 40-43 gate type. bit 45-46 dpl. bit 47 present bit
dw 0x00 ;offset bits 16-31
Invalid_TSS_INT15:
;each entry is 64 bits (damn lol what a pain)
dw 0x00 ;offset bits 0-15
dw 0x10 ;segment selector 16 bits
dw 0xEE00 ;bits32-39 reserved. bits 40-43 gate type. bit 45-46 dpl. bit 47 present bit
dw 0x00 ;offset bits 16-31
Invalid_TSS_INT16:
;each entry is 64 bits (damn lol what a pain)
dw 0x00 ;offset bits 0-15
dw 0x10 ;segment selector 16 bits
dw 0xEE00 ;bits32-39 reserved. bits 40-43 gate type. bit 45-46 dpl. bit 47 present bit
dw 0x00 ;offset bits 16-31
end_of_idt:
top_idt:
dw end_of_idt - idt - 1
dd idt
%include "drivers/vgadriver.asm"