WebSVN – HelenOS – Diff – /SPARTAN/trunk/arch/ia32/src/asm.S


#
# Copyright (C) 2001-2004 Jakub Jermar
# All rights reserved.
#
# Redistribution and use in source and binary forms, with or without
# modification, are permitted provided that the following conditions
# are met:
#
# - Redistributions of source code must retain the above copyright
#   notice, this list of conditions and the following disclaimer.
# - Redistributions in binary form must reproduce the above copyright
#   notice, this list of conditions and the following disclaimer in the
#   documentation and/or other materials provided with the distribution.
# - The name of the author may not be used to endorse or promote products
#   derived from this software without specific prior written permission.
#
# THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
# IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
# OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
# IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
# INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
# NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
# DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
# THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
# (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
# THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
#
 
## very low and hardware-level functions
 
#define ERROR_WORD_INTERRUPT_LIST 0x00027D00
 
.text
 
.global cpu_halt
.global cpu_sleep
.global paging_on
.global enable_l_apic_in_msr
.global interrupt_handlers
.global inb
.global inw
.global inl
.global outb
.global outw
.global outl
.global memcopy
.global memsetb
.global memsetw
.global memcmp
 
 
## Turn paging on
#
# Enable paging and write-back caching in CR0.
#
paging_on:
	pushl %eax
	movl %cr0,%eax
	orl $(1<<31),%eax		# paging on
	andl $~((1<<30)|(1<<29)),%eax	# clear Cache Disable and not Write Though
	movl %eax,%cr0
	jmp 0f
0:
	popl %eax
	ret
 
 
## Enable local APIC
#
# Enable local APIC in MSR.
#
enable_l_apic_in_msr:
	pusha
	
	movl $0x1b, %ecx
	rdmsr
	orl $(1<<11),%eax
	orl $(0xfee00000),%eax
	wrmsr
	
	popa
	ret
 
 
## Declare interrupt handlers
#
# Declare interrupt handlers for n interrupt
# vectors starting at vector i.
#
# The handlers setup data segment registers
# and call trap_dispatcher().
#
.macro handler i n
	push %ebp
	movl %esp,%ebp
	pusha
 
	push %ds
	push %es
 
	# we must fill the data segment registers
	movw $16,%ax
	movw %ax,%ds
	movw %ax,%es
 
	movl $(\i),%edi
	pushl %ebp
	addl $4,(%esp)
	pushl %edi
	call trap_dispatcher
	addl $8,%esp
 
	pop %es
	pop %ds
 
	mov $\i,%cl;
	movl $1,%eax;
	test $0xe0,%cl;
	jnz 0f;
	and $0x1f,%cl;
	shl %cl,%eax;
	and $ERROR_WORD_INTERRUPT_LIST,%eax;
	jz 0f;
 
	popa;
	pop %ebp;
	add $4,%esp;
	iret;
 
0:
 
	popa
	pop %ebp
	iret
 
	.if (\n-\i)-1
	handler "(\i+1)",\n
	.endif
.endm
 
# keep in sync with pm.h !!!
IDT_ITEMS=64
interrupt_handlers:
h_start:
	handler 0 64
#	handler 64 128	
#	handler 128 192
#	handler 192 256
h_end:
 
 
## I/O input (byte)
#
# Get a byte from I/O port and store it AL.
#
inb:
	push %edx
	xorl %eax,%eax
	movl 8(%esp),%edx
	inb %dx,%al
	pop %edx
	ret
 
 
## I/O input (word)
#
# Get a word from I/O port and store it AX.
#
inw:
	push %edx
	xorl %eax,%eax
	movl 8(%esp),%edx
	inw %dx,%ax
	pop %edx
	ret
 
 
## I/O input (dword)
#
# Get a dword from I/O port and store it EAX.
#
inl:
	push %edx
	xorl %eax,%eax
	movl 8(%esp),%edx
	inl %dx,%eax
	pop %edx
	ret
 
 
## I/O output (byte)
#
# Send a byte to I/O port.
#
outb:
	push %ebp
	movl %esp,%ebp
	pusha
 
	movl 8(%ebp),%edx
	movl 12(%ebp),%eax
	outb %al,%dx
 
	popa
	pop %ebp
	ret
 
 
## I/O output (word)
#
# Send a word to I/O port.
#
outw:
	push %ebp
	movl %esp,%ebp
	pusha
 
	movl 8(%ebp),%edx
	movl 12(%ebp),%eax
	outw %ax,%dx
 
	popa
	pop %ebp
	ret
 
 
## I/O output (dword)
#
# Send a dword to I/O port.
#
outl:
	push %ebp
	movl %esp,%ebp
	pusha
 
	movl 8(%ebp),%edx
	movl 12(%ebp),%eax
	outl %eax,%dx
 
	popa
	pop %ebp
	ret
 
 
## Copy memory
#
# Copy a given number of bytes (3rd argument)
# from the memory location defined by 1st argument
# to the memory location defined by 2nd argument.
# The memory areas cannot overlap.
#
SRC=8
DST=12
CNT=16
memcopy:
	push %ebp
	movl %esp,%ebp
	pusha
 
	cld
	movl CNT(%ebp),%ecx
	movl DST(%ebp),%edi
	movl SRC(%ebp),%esi
 
	rep movsb %ds:(%esi),%es:(%edi)
 
	popa
	pop %ebp
	ret
 
 
## Fill memory with bytes
#
# Fill a given number of bytes (2nd argument)
# at memory defined by 1st argument with the
# byte value defined by 3rd argument.
#
DST=8
CNT=12
X=16
memsetb:
	push %ebp
	movl %esp,%ebp
	pusha
 
	cld
	movl CNT(%ebp),%ecx
	movl DST(%ebp),%edi
	movl X(%ebp),%eax
 
	rep stosb %al,%es:(%edi)
 
	popa
	pop %ebp
	ret
 
 
## Fill memory with words
#
# Fill a given number of words (2nd argument)
# at memory defined by 1st argument with the
# word value defined by 3rd argument.
#
DST=8
CNT=12
X=16
memsetw:
	push %ebp
	movl %esp,%ebp
	pusha
 
	cld
	movl CNT(%ebp),%ecx
	movl DST(%ebp),%edi
	movl X(%ebp),%eax
 
	rep stosw %ax,%es:(%edi)
 
	popa
	pop %ebp
	ret
 
 
## Compare memory regions for equality
#
# Compare a given number of bytes (3rd argument)
# at memory locations defined by 1st and 2nd argument
# for equality. If the bytes are equal, EAX contains
# 0.
#
SRC=12
DST=16
CNT=20
memcmp:
	push %ebp
	subl $4,%esp	
	movl %esp,%ebp
 
	pusha
 
	cld
	movl CNT(%ebp),%ecx
	movl DST(%ebp),%edi
	movl SRC(%ebp),%esi
 
	repe cmpsb %es:(%edi),%ds:(%esi)
	movl %ecx,(%ebp)
 
	popa
	
	movl (%ebp),%eax	# return value => %eax (zero on success)
	addl $4,%esp
	pop %ebp
	
	ret
 
 
# THIS IS USERSPACE CODE
.global utext
utext:
	xor %ax,%ax;
	mov %ax,%ds;
	mov %ax,%es;
	mov %ax,%fs;
	mov %ax,%gs;
0:
#	movl $0xdeadbeaf, %eax
  int $48
	cli;
	sti;
	jmp 0b
	# not reached
utext_end:
 
.data
.global utext_size
utext_size:
	.long utext_end - utext 
 
 
#.section K_DATA_START
.global interrupt_handler_size
 
interrupt_handler_size: .long (h_end-h_start)/IDT_ITEMS
 

Rev 132	Rev 136
1	#	1	#
2	# Copyright (C) 2001-2004 Jakub Jermar	2	# Copyright (C) 2001-2004 Jakub Jermar
3	# All rights reserved.	3	# All rights reserved.
4	#	4	#
5	# Redistribution and use in source and binary forms, with or without	5	# Redistribution and use in source and binary forms, with or without
6	# modification, are permitted provided that the following conditions	6	# modification, are permitted provided that the following conditions
7	# are met:	7	# are met:
8	#	8	#
9	# - Redistributions of source code must retain the above copyright	9	# - Redistributions of source code must retain the above copyright
10	# notice, this list of conditions and the following disclaimer.	10	# notice, this list of conditions and the following disclaimer.
11	# - Redistributions in binary form must reproduce the above copyright	11	# - Redistributions in binary form must reproduce the above copyright
12	# notice, this list of conditions and the following disclaimer in the	12	# notice, this list of conditions and the following disclaimer in the
13	# documentation and/or other materials provided with the distribution.	13	# documentation and/or other materials provided with the distribution.
14	# - The name of the author may not be used to endorse or promote products	14	# - The name of the author may not be used to endorse or promote products
15	# derived from this software without specific prior written permission.	15	# derived from this software without specific prior written permission.
16	#	16	#
17	# THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR	17	# THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
18	# IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES	18	# IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
19	# OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.	19	# OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
20	# IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,	20	# IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
21	# INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT	21	# INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
22	# NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,	22	# NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
23	# DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY	23	# DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
24	# THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT	24	# THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
25	# (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF	25	# (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
26	# THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.	26	# THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
27	#	27	#
28		28
29	## very low and hardware-level functions	29	## very low and hardware-level functions
30		30
31	#define ERROR_WORD_INTERRUPT_LIST 0x00027D00	31	#define ERROR_WORD_INTERRUPT_LIST 0x00027D00
32		32
33	.text	33	.text
34		34
35	.global cpu_halt	35	.global cpu_halt
36	.global cpu_sleep	36	.global cpu_sleep
37	.global paging_on	37	.global paging_on
38	.global enable_l_apic_in_msr	38	.global enable_l_apic_in_msr
39	.global interrupt_handlers	39	.global interrupt_handlers
40	.global inb	40	.global inb
41	.global inw	41	.global inw
42	.global inl	42	.global inl
43	.global outb	43	.global outb
44	.global outw	44	.global outw
45	.global outl	45	.global outl
46	.global memcopy	46	.global memcopy
47	.global memsetb	47	.global memsetb
48	.global memsetw	48	.global memsetw
49	.global memcmp	49	.global memcmp
50		50
51		51
52	## Turn paging on	52	## Turn paging on
53	#	53	#
54	# Enable paging and write-back caching in CR0.	54	# Enable paging and write-back caching in CR0.
55	#	55	#
56	paging_on:	56	paging_on:
57	pushl %eax	57	pushl %eax
58	movl %cr0,%eax	58	movl %cr0,%eax
59	orl $(1<<31),%eax # paging on	59	orl $(1<<31),%eax # paging on
60	andl $~((1<<30)\|(1<<29)),%eax # clear Cache Disable and not Write Though	60	andl $~((1<<30)\|(1<<29)),%eax # clear Cache Disable and not Write Though
61	movl %eax,%cr0	61	movl %eax,%cr0
62	jmp 0f	62	jmp 0f
63	0:	63	0:
64	popl %eax	64	popl %eax
65	ret	65	ret
66		66
67		67
68	## Enable local APIC	68	## Enable local APIC
69	#	69	#
70	# Enable local APIC in MSR.	70	# Enable local APIC in MSR.
71	#	71	#
72	enable_l_apic_in_msr:	72	enable_l_apic_in_msr:
73	pusha	73	pusha
74		74
75	movl $0x1b, %ecx	75	movl $0x1b, %ecx
76	rdmsr	76	rdmsr
77	orl $(1<<11),%eax	77	orl $(1<<11),%eax
78	orl $(0xfee00000),%eax	78	orl $(0xfee00000),%eax
79	wrmsr	79	wrmsr
80		80
81	popa	81	popa
82	ret	82	ret
83		83
84		84
85	## Declare interrupt handlers	85	## Declare interrupt handlers
86	#	86	#
87	# Declare interrupt handlers for n interrupt	87	# Declare interrupt handlers for n interrupt
88	# vectors starting at vector i.	88	# vectors starting at vector i.
89	#	89	#
90	# The handlers setup data segment registers	90	# The handlers setup data segment registers
91	# and call trap_dispatcher().	91	# and call trap_dispatcher().
92	#	92	#
93	.macro handler i n	93	.macro handler i n
94	push %ebp	94	push %ebp
95	movl %esp,%ebp	95	movl %esp,%ebp
96	pusha	96	pusha
97		97
98	push %ds	98	push %ds
99	push %es	99	push %es
100		100
101	# we must fill the data segment registers	101	# we must fill the data segment registers
102	movw $16,%ax	102	movw $16,%ax
103	movw %ax,%ds	103	movw %ax,%ds
104	movw %ax,%es	104	movw %ax,%es
105		105
106	movl $(\i),%edi	106	movl $(\i),%edi
107	pushl %ebp	107	pushl %ebp
108	addl $4,(%esp)	108	addl $4,(%esp)
109	pushl %edi	109	pushl %edi
110	call trap_dispatcher	110	call trap_dispatcher
111	addl $8,%esp	111	addl $8,%esp
112		112
113	pop %es	113	pop %es
114	pop %ds	114	pop %ds
115		115
116	mov $\i,%cl;	116	mov $\i,%cl;
117	movl $1,%eax;	117	movl $1,%eax;
118	test $0xe0,%cl;	118	test $0xe0,%cl;
119	jnz 0f;	119	jnz 0f;
-		120	and $0x1f,%cl;
120	shl %cl,%eax;	121	shl %cl,%eax;
121	and $ERROR_WORD_INTERRUPT_LIST,%eax;	122	and $ERROR_WORD_INTERRUPT_LIST,%eax;
122	jnz 0f;	123	jz 0f;
123		124
124	popa;	125	popa;
125	pop %ebp;	126	pop %ebp;
126	add $4,%esp;	127	add $4,%esp;
127	iret;	128	iret;
128		129
129	0:	130	0:
130		131
131	popa	132	popa
132	pop %ebp	133	pop %ebp
133	iret	134	iret
134		135
135	.if (\n-\i)-1	136	.if (\n-\i)-1
136	handler "(\i+1)",\n	137	handler "(\i+1)",\n
137	.endif	138	.endif
138	.endm	139	.endm
139		140
140	# keep in sync with pm.h !!!	141	# keep in sync with pm.h !!!
141	IDT_ITEMS=64	142	IDT_ITEMS=64
142	interrupt_handlers:	143	interrupt_handlers:
143	h_start:	144	h_start:
144	handler 0 64	145	handler 0 64
145	# handler 64 128	146	# handler 64 128
146	# handler 128 192	147	# handler 128 192
147	# handler 192 256	148	# handler 192 256
148	h_end:	149	h_end:
149		150
150		151
151	## I/O input (byte)	152	## I/O input (byte)
152	#	153	#
153	# Get a byte from I/O port and store it AL.	154	# Get a byte from I/O port and store it AL.
154	#	155	#
155	inb:	156	inb:
156	push %edx	157	push %edx
157	xorl %eax,%eax	158	xorl %eax,%eax
158	movl 8(%esp),%edx	159	movl 8(%esp),%edx
159	inb %dx,%al	160	inb %dx,%al
160	pop %edx	161	pop %edx
161	ret	162	ret
162		163
163		164
164	## I/O input (word)	165	## I/O input (word)
165	#	166	#
166	# Get a word from I/O port and store it AX.	167	# Get a word from I/O port and store it AX.
167	#	168	#
168	inw:	169	inw:
169	push %edx	170	push %edx
170	xorl %eax,%eax	171	xorl %eax,%eax
171	movl 8(%esp),%edx	172	movl 8(%esp),%edx
172	inw %dx,%ax	173	inw %dx,%ax
173	pop %edx	174	pop %edx
174	ret	175	ret
175		176
176		177
177	## I/O input (dword)	178	## I/O input (dword)
178	#	179	#
179	# Get a dword from I/O port and store it EAX.	180	# Get a dword from I/O port and store it EAX.
180	#	181	#
181	inl:	182	inl:
182	push %edx	183	push %edx
183	xorl %eax,%eax	184	xorl %eax,%eax
184	movl 8(%esp),%edx	185	movl 8(%esp),%edx
185	inl %dx,%eax	186	inl %dx,%eax
186	pop %edx	187	pop %edx
187	ret	188	ret
188		189
189		190
190	## I/O output (byte)	191	## I/O output (byte)
191	#	192	#
192	# Send a byte to I/O port.	193	# Send a byte to I/O port.
193	#	194	#
194	outb:	195	outb:
195	push %ebp	196	push %ebp
196	movl %esp,%ebp	197	movl %esp,%ebp
197	pusha	198	pusha
198		199
199	movl 8(%ebp),%edx	200	movl 8(%ebp),%edx
200	movl 12(%ebp),%eax	201	movl 12(%ebp),%eax
201	outb %al,%dx	202	outb %al,%dx
202		203
203	popa	204	popa
204	pop %ebp	205	pop %ebp
205	ret	206	ret
206		207
207		208
208	## I/O output (word)	209	## I/O output (word)
209	#	210	#
210	# Send a word to I/O port.	211	# Send a word to I/O port.
211	#	212	#
212	outw:	213	outw:
213	push %ebp	214	push %ebp
214	movl %esp,%ebp	215	movl %esp,%ebp
215	pusha	216	pusha
216		217
217	movl 8(%ebp),%edx	218	movl 8(%ebp),%edx
218	movl 12(%ebp),%eax	219	movl 12(%ebp),%eax
219	outw %ax,%dx	220	outw %ax,%dx
220		221
221	popa	222	popa
222	pop %ebp	223	pop %ebp
223	ret	224	ret
224		225
225		226
226	## I/O output (dword)	227	## I/O output (dword)
227	#	228	#
228	# Send a dword to I/O port.	229	# Send a dword to I/O port.
229	#	230	#
230	outl:	231	outl:
231	push %ebp	232	push %ebp
232	movl %esp,%ebp	233	movl %esp,%ebp
233	pusha	234	pusha
234		235
235	movl 8(%ebp),%edx	236	movl 8(%ebp),%edx
236	movl 12(%ebp),%eax	237	movl 12(%ebp),%eax
237	outl %eax,%dx	238	outl %eax,%dx
238		239
239	popa	240	popa
240	pop %ebp	241	pop %ebp
241	ret	242	ret
242		243
243		244
244	## Copy memory	245	## Copy memory
245	#	246	#
246	# Copy a given number of bytes (3rd argument)	247	# Copy a given number of bytes (3rd argument)
247	# from the memory location defined by 1st argument	248	# from the memory location defined by 1st argument
248	# to the memory location defined by 2nd argument.	249	# to the memory location defined by 2nd argument.
249	# The memory areas cannot overlap.	250	# The memory areas cannot overlap.
250	#	251	#
251	SRC=8	252	SRC=8
252	DST=12	253	DST=12
253	CNT=16	254	CNT=16
254	memcopy:	255	memcopy:
255	push %ebp	256	push %ebp
256	movl %esp,%ebp	257	movl %esp,%ebp
257	pusha	258	pusha
258		259
259	cld	260	cld
260	movl CNT(%ebp),%ecx	261	movl CNT(%ebp),%ecx
261	movl DST(%ebp),%edi	262	movl DST(%ebp),%edi
262	movl SRC(%ebp),%esi	263	movl SRC(%ebp),%esi
263		264
264	rep movsb %ds:(%esi),%es:(%edi)	265	rep movsb %ds:(%esi),%es:(%edi)
265		266
266	popa	267	popa
267	pop %ebp	268	pop %ebp
268	ret	269	ret
269		270
270		271
271	## Fill memory with bytes	272	## Fill memory with bytes
272	#	273	#
273	# Fill a given number of bytes (2nd argument)	274	# Fill a given number of bytes (2nd argument)
274	# at memory defined by 1st argument with the	275	# at memory defined by 1st argument with the
275	# byte value defined by 3rd argument.	276	# byte value defined by 3rd argument.
276	#	277	#
277	DST=8	278	DST=8
278	CNT=12	279	CNT=12
279	X=16	280	X=16
280	memsetb:	281	memsetb:
281	push %ebp	282	push %ebp
282	movl %esp,%ebp	283	movl %esp,%ebp
283	pusha	284	pusha
284		285
285	cld	286	cld
286	movl CNT(%ebp),%ecx	287	movl CNT(%ebp),%ecx
287	movl DST(%ebp),%edi	288	movl DST(%ebp),%edi
288	movl X(%ebp),%eax	289	movl X(%ebp),%eax
289		290
290	rep stosb %al,%es:(%edi)	291	rep stosb %al,%es:(%edi)
291		292
292	popa	293	popa
293	pop %ebp	294	pop %ebp
294	ret	295	ret
295		296
296		297
297	## Fill memory with words	298	## Fill memory with words
298	#	299	#
299	# Fill a given number of words (2nd argument)	300	# Fill a given number of words (2nd argument)
300	# at memory defined by 1st argument with the	301	# at memory defined by 1st argument with the
301	# word value defined by 3rd argument.	302	# word value defined by 3rd argument.
302	#	303	#
303	DST=8	304	DST=8
304	CNT=12	305	CNT=12
305	X=16	306	X=16
306	memsetw:	307	memsetw:
307	push %ebp	308	push %ebp
308	movl %esp,%ebp	309	movl %esp,%ebp
309	pusha	310	pusha
310		311
311	cld	312	cld
312	movl CNT(%ebp),%ecx	313	movl CNT(%ebp),%ecx
313	movl DST(%ebp),%edi	314	movl DST(%ebp),%edi
314	movl X(%ebp),%eax	315	movl X(%ebp),%eax
315		316
316	rep stosw %ax,%es:(%edi)	317	rep stosw %ax,%es:(%edi)
317		318
318	popa	319	popa
319	pop %ebp	320	pop %ebp
320	ret	321	ret
321		322
322		323
323	## Compare memory regions for equality	324	## Compare memory regions for equality
324	#	325	#
325	# Compare a given number of bytes (3rd argument)	326	# Compare a given number of bytes (3rd argument)
326	# at memory locations defined by 1st and 2nd argument	327	# at memory locations defined by 1st and 2nd argument
327	# for equality. If the bytes are equal, EAX contains	328	# for equality. If the bytes are equal, EAX contains
328	# 0.	329	# 0.
329	#	330	#
330	SRC=12	331	SRC=12
331	DST=16	332	DST=16
332	CNT=20	333	CNT=20
333	memcmp:	334	memcmp:
334	push %ebp	335	push %ebp
335	subl $4,%esp	336	subl $4,%esp
336	movl %esp,%ebp	337	movl %esp,%ebp
337		338
338	pusha	339	pusha
339		340
340	cld	341	cld
341	movl CNT(%ebp),%ecx	342	movl CNT(%ebp),%ecx
342	movl DST(%ebp),%edi	343	movl DST(%ebp),%edi
343	movl SRC(%ebp),%esi	344	movl SRC(%ebp),%esi
344		345
345	repe cmpsb %es:(%edi),%ds:(%esi)	346	repe cmpsb %es:(%edi),%ds:(%esi)
346	movl %ecx,(%ebp)	347	movl %ecx,(%ebp)
347		348
348	popa	349	popa
349		350
350	movl (%ebp),%eax # return value => %eax (zero on success)	351	movl (%ebp),%eax # return value => %eax (zero on success)
351	addl $4,%esp	352	addl $4,%esp
352	pop %ebp	353	pop %ebp
353		354
354	ret	355	ret
355		356
356		357
357	# THIS IS USERSPACE CODE	358	# THIS IS USERSPACE CODE
358	.global utext	359	.global utext
359	utext:	360	utext:
-		361	xor %ax,%ax;
-		362	mov %ax,%ds;
-		363	mov %ax,%es;
-		364	mov %ax,%fs;
-		365	mov %ax,%gs;
360	0:	366	0:
361	# movl $0xdeadbeaf, %eax	367	# movl $0xdeadbeaf, %eax
362	int $48	368	int $48
-		369	cli;
-		370	sti;
363	jmp 0b	371	jmp 0b
364	# not reached	372	# not reached
365	utext_end:	373	utext_end:
366		374
367	.data	375	.data
368	.global utext_size	376	.global utext_size
369	utext_size:	377	utext_size:
370	.long utext_end - utext	378	.long utext_end - utext
371		379
372		380
373	#.section K_DATA_START	381	#.section K_DATA_START
374	.global interrupt_handler_size	382	.global interrupt_handler_size
375		383
376	interrupt_handler_size: .long (h_end-h_start)/IDT_ITEMS	384	interrupt_handler_size: .long (h_end-h_start)/IDT_ITEMS
377		385

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(root)/SPARTAN/trunk/arch/ia32/src/asm.S @ 358 – Rev 132 → 136