WebSVN – HelenOS-historic – 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
 
#  Mask for interrupts 0 - 31 (bits 0 - 31) where 0 means that int has no error word
# and 1 means interrupt with error word
#define ERROR_WORD_INTERRUPT_LIST 0x00027D00
 
.text
 
 
 
.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
 
 
# CLNT
  pushfl;
	pop %eax;
	and $0xFFFFBFFF,%eax;
	push %eax;
	popfl;
	
 
 
# Test if this is interrupt with error word or not
	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;
 
 
# Return with error word
	popa;
	pop %ebp;
	add $4,%esp;    # Skip error word
	iret;
 
0:
# Return with no error word
	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:
	int $48
	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 168	Rev 185
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	# Mask for interrupts 0 - 31 (bits 0 - 31) where 0 means that int has no error word	31	# Mask for interrupts 0 - 31 (bits 0 - 31) where 0 means that int has no error word
32	# and 1 means interrupt with error word	32	# and 1 means interrupt with error word
33	#define ERROR_WORD_INTERRUPT_LIST 0x00027D00	33	#define ERROR_WORD_INTERRUPT_LIST 0x00027D00
34		34
35	.text	35	.text
36		36
37	.global cpu_halt	-
38	.global cpu_sleep	-
39	.global paging_on	37	.global paging_on
40	.global enable_l_apic_in_msr	38	.global enable_l_apic_in_msr
41	.global interrupt_handlers	39	.global interrupt_handlers
42	.global inb	40	.global inb
43	.global inw	41	.global inw
44	.global inl	42	.global inl
45	.global outb	43	.global outb
46	.global outw	44	.global outw
47	.global outl	45	.global outl
48	.global memcopy	46	.global memcopy
49	.global memsetb	47	.global memsetb
50	.global memsetw	48	.global memsetw
51	.global memcmp	49	.global memcmp
52		50
53		51
54	## Turn paging on	52	## Turn paging on
55	#	53	#
56	# Enable paging and write-back caching in CR0.	54	# Enable paging and write-back caching in CR0.
57	#	55	#
58	paging_on:	56	paging_on:
59	pushl %eax	57	pushl %eax
60	movl %cr0,%eax	58	movl %cr0,%eax
61	orl $(1<<31),%eax # paging on	59	orl $(1<<31),%eax # paging on
62	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
63	movl %eax,%cr0	61	movl %eax,%cr0
64	jmp 0f	62	jmp 0f
65	0:	63	0:
66	popl %eax	64	popl %eax
67	ret	65	ret
68		66
69		67
70	## Enable local APIC	68	## Enable local APIC
71	#	69	#
72	# Enable local APIC in MSR.	70	# Enable local APIC in MSR.
73	#	71	#
74	enable_l_apic_in_msr:	72	enable_l_apic_in_msr:
75	pusha	73	pusha
76		74
77	movl $0x1b, %ecx	75	movl $0x1b, %ecx
78	rdmsr	76	rdmsr
79	orl $(1<<11),%eax	77	orl $(1<<11),%eax
80	orl $(0xfee00000),%eax	78	orl $(0xfee00000),%eax
81	wrmsr	79	wrmsr
82		80
83	popa	81	popa
84	ret	82	ret
85		83
86		84
87	## Declare interrupt handlers	85	## Declare interrupt handlers
88	#	86	#
89	# Declare interrupt handlers for n interrupt	87	# Declare interrupt handlers for n interrupt
90	# vectors starting at vector i.	88	# vectors starting at vector i.
91	#	89	#
92	# The handlers setup data segment registers	90	# The handlers setup data segment registers
93	# and call trap_dispatcher().	91	# and call trap_dispatcher().
94	#	92	#
95	.macro handler i n	93	.macro handler i n
96	push %ebp	94	push %ebp
97	movl %esp,%ebp	95	movl %esp,%ebp
98	pusha	96	pusha
99		97
100	push %ds	98	push %ds
101	push %es	99	push %es
102		100
103	# we must fill the data segment registers	101	# we must fill the data segment registers
104	movw $16,%ax	102	movw $16,%ax
105	movw %ax,%ds	103	movw %ax,%ds
106	movw %ax,%es	104	movw %ax,%es
107		105
108	movl $(\i),%edi	106	movl $(\i),%edi
109	pushl %ebp	107	pushl %ebp
110	addl $4,(%esp)	108	addl $4,(%esp)
111	pushl %edi	109	pushl %edi
112	call trap_dispatcher	110	call trap_dispatcher
113	addl $8,%esp	111	addl $8,%esp
114		112
115	pop %es	113	pop %es
116	pop %ds	114	pop %ds
117		115
118		116
119	# CLNT	117	# CLNT
120	pushfl;	118	pushfl;
121	pop %eax;	119	pop %eax;
122	and $0xFFFFBFFF,%eax;	120	and $0xFFFFBFFF,%eax;
123	push %eax;	121	push %eax;
124	popfl;	122	popfl;
125		123
126		124
127		125
128	# Test if this is interrupt with error word or not	126	# Test if this is interrupt with error word or not
129	mov $\i,%cl;	127	mov $\i,%cl;
130	movl $1,%eax;	128	movl $1,%eax;
131	test $0xe0,%cl;	129	test $0xe0,%cl;
132	jnz 0f;	130	jnz 0f;
133	and $0x1f,%cl;	131	and $0x1f,%cl;
134	shl %cl,%eax;	132	shl %cl,%eax;
135	and $ERROR_WORD_INTERRUPT_LIST,%eax;	133	and $ERROR_WORD_INTERRUPT_LIST,%eax;
136	jz 0f;	134	jz 0f;
137		135
138		136
139	# Return with error word	137	# Return with error word
140	popa;	138	popa;
141	pop %ebp;	139	pop %ebp;
142	add $4,%esp; # Skip error word	140	add $4,%esp; # Skip error word
143	iret;	141	iret;
144		142
145	0:	143	0:
146	# Return with no error word	144	# Return with no error word
147	popa	145	popa
148	pop %ebp	146	pop %ebp
149	iret	147	iret
150		148
151	.if (\n-\i)-1	149	.if (\n-\i)-1
152	handler "(\i+1)",\n	150	handler "(\i+1)",\n
153	.endif	151	.endif
154	.endm	152	.endm
155		153
156	# keep in sync with pm.h !!!	154	# keep in sync with pm.h !!!
157	IDT_ITEMS=64	155	IDT_ITEMS=64
158	interrupt_handlers:	156	interrupt_handlers:
159	h_start:	157	h_start:
160	handler 0 64	158	handler 0 64
161	# handler 64 128	159	# handler 64 128
162	# handler 128 192	160	# handler 128 192
163	# handler 192 256	161	# handler 192 256
164	h_end:	162	h_end:
165		163
166		164
167	## I/O input (byte)	165	## I/O input (byte)
168	#	166	#
169	# Get a byte from I/O port and store it AL.	167	# Get a byte from I/O port and store it AL.
170	#	168	#
171	inb:	169	inb:
172	push %edx	170	push %edx
173	xorl %eax,%eax	171	xorl %eax,%eax
174	movl 8(%esp),%edx	172	movl 8(%esp),%edx
175	inb %dx,%al	173	inb %dx,%al
176	pop %edx	174	pop %edx
177	ret	175	ret
178		176
179		177
180	## I/O input (word)	178	## I/O input (word)
181	#	179	#
182	# Get a word from I/O port and store it AX.	180	# Get a word from I/O port and store it AX.
183	#	181	#
184	inw:	182	inw:
185	push %edx	183	push %edx
186	xorl %eax,%eax	184	xorl %eax,%eax
187	movl 8(%esp),%edx	185	movl 8(%esp),%edx
188	inw %dx,%ax	186	inw %dx,%ax
189	pop %edx	187	pop %edx
190	ret	188	ret
191		189
192		190
193	## I/O input (dword)	191	## I/O input (dword)
194	#	192	#
195	# Get a dword from I/O port and store it EAX.	193	# Get a dword from I/O port and store it EAX.
196	#	194	#
197	inl:	195	inl:
198	push %edx	196	push %edx
199	xorl %eax,%eax	197	xorl %eax,%eax
200	movl 8(%esp),%edx	198	movl 8(%esp),%edx
201	inl %dx,%eax	199	inl %dx,%eax
202	pop %edx	200	pop %edx
203	ret	201	ret
204		202
205		203
206	## I/O output (byte)	204	## I/O output (byte)
207	#	205	#
208	# Send a byte to I/O port.	206	# Send a byte to I/O port.
209	#	207	#
210	outb:	208	outb:
211	push %ebp	209	push %ebp
212	movl %esp,%ebp	210	movl %esp,%ebp
213	pusha	211	pusha
214		212
215	movl 8(%ebp),%edx	213	movl 8(%ebp),%edx
216	movl 12(%ebp),%eax	214	movl 12(%ebp),%eax
217	outb %al,%dx	215	outb %al,%dx
218		216
219	popa	217	popa
220	pop %ebp	218	pop %ebp
221	ret	219	ret
222		220
223		221
224	## I/O output (word)	222	## I/O output (word)
225	#	223	#
226	# Send a word to I/O port.	224	# Send a word to I/O port.
227	#	225	#
228	outw:	226	outw:
229	push %ebp	227	push %ebp
230	movl %esp,%ebp	228	movl %esp,%ebp
231	pusha	229	pusha
232		230
233	movl 8(%ebp),%edx	231	movl 8(%ebp),%edx
234	movl 12(%ebp),%eax	232	movl 12(%ebp),%eax
235	outw %ax,%dx	233	outw %ax,%dx
236		234
237	popa	235	popa
238	pop %ebp	236	pop %ebp
239	ret	237	ret
240		238
241		239
242	## I/O output (dword)	240	## I/O output (dword)
243	#	241	#
244	# Send a dword to I/O port.	242	# Send a dword to I/O port.
245	#	243	#
246	outl:	244	outl:
247	push %ebp	245	push %ebp
248	movl %esp,%ebp	246	movl %esp,%ebp
249	pusha	247	pusha
250		248
251	movl 8(%ebp),%edx	249	movl 8(%ebp),%edx
252	movl 12(%ebp),%eax	250	movl 12(%ebp),%eax
253	outl %eax,%dx	251	outl %eax,%dx
254		252
255	popa	253	popa
256	pop %ebp	254	pop %ebp
257	ret	255	ret
258		256
259		257
260	## Copy memory	258	## Copy memory
261	#	259	#
262	# Copy a given number of bytes (3rd argument)	260	# Copy a given number of bytes (3rd argument)
263	# from the memory location defined by 1st argument	261	# from the memory location defined by 1st argument
264	# to the memory location defined by 2nd argument.	262	# to the memory location defined by 2nd argument.
265	# The memory areas cannot overlap.	263	# The memory areas cannot overlap.
266	#	264	#
267	SRC=8	265	SRC=8
268	DST=12	266	DST=12
269	CNT=16	267	CNT=16
270	memcopy:	268	memcopy:
271	push %ebp	269	push %ebp
272	movl %esp,%ebp	270	movl %esp,%ebp
273	pusha	271	pusha
274		272
275	cld	273	cld
276	movl CNT(%ebp),%ecx	274	movl CNT(%ebp),%ecx
277	movl DST(%ebp),%edi	275	movl DST(%ebp),%edi
278	movl SRC(%ebp),%esi	276	movl SRC(%ebp),%esi
279		277
280	rep movsb %ds:(%esi),%es:(%edi)	278	rep movsb %ds:(%esi),%es:(%edi)
281		279
282	popa	280	popa
283	pop %ebp	281	pop %ebp
284	ret	282	ret
285		283
286		284
287	## Fill memory with bytes	285	## Fill memory with bytes
288	#	286	#
289	# Fill a given number of bytes (2nd argument)	287	# Fill a given number of bytes (2nd argument)
290	# at memory defined by 1st argument with the	288	# at memory defined by 1st argument with the
291	# byte value defined by 3rd argument.	289	# byte value defined by 3rd argument.
292	#	290	#
293	DST=8	291	DST=8
294	CNT=12	292	CNT=12
295	X=16	293	X=16
296	memsetb:	294	memsetb:
297	push %ebp	295	push %ebp
298	movl %esp,%ebp	296	movl %esp,%ebp
299	pusha	297	pusha
300		298
301	cld	299	cld
302	movl CNT(%ebp),%ecx	300	movl CNT(%ebp),%ecx
303	movl DST(%ebp),%edi	301	movl DST(%ebp),%edi
304	movl X(%ebp),%eax	302	movl X(%ebp),%eax
305		303
306	rep stosb %al,%es:(%edi)	304	rep stosb %al,%es:(%edi)
307		305
308	popa	306	popa
309	pop %ebp	307	pop %ebp
310	ret	308	ret
311		309
312		310
313	## Fill memory with words	311	## Fill memory with words
314	#	312	#
315	# Fill a given number of words (2nd argument)	313	# Fill a given number of words (2nd argument)
316	# at memory defined by 1st argument with the	314	# at memory defined by 1st argument with the
317	# word value defined by 3rd argument.	315	# word value defined by 3rd argument.
318	#	316	#
319	DST=8	317	DST=8
320	CNT=12	318	CNT=12
321	X=16	319	X=16
322	memsetw:	320	memsetw:
323	push %ebp	321	push %ebp
324	movl %esp,%ebp	322	movl %esp,%ebp
325	pusha	323	pusha
326		324
327	cld	325	cld
328	movl CNT(%ebp),%ecx	326	movl CNT(%ebp),%ecx
329	movl DST(%ebp),%edi	327	movl DST(%ebp),%edi
330	movl X(%ebp),%eax	328	movl X(%ebp),%eax
331		329
332	rep stosw %ax,%es:(%edi)	330	rep stosw %ax,%es:(%edi)
333		331
334	popa	332	popa
335	pop %ebp	333	pop %ebp
336	ret	334	ret
337		335
338		336
339	## Compare memory regions for equality	337	## Compare memory regions for equality
340	#	338	#
341	# Compare a given number of bytes (3rd argument)	339	# Compare a given number of bytes (3rd argument)
342	# at memory locations defined by 1st and 2nd argument	340	# at memory locations defined by 1st and 2nd argument
343	# for equality. If the bytes are equal, EAX contains	341	# for equality. If the bytes are equal, EAX contains
344	# 0.	342	# 0.
345	#	343	#
346	SRC=12	344	SRC=12
347	DST=16	345	DST=16
348	CNT=20	346	CNT=20
349	memcmp:	347	memcmp:
350	push %ebp	348	push %ebp
351	subl $4,%esp	349	subl $4,%esp
352	movl %esp,%ebp	350	movl %esp,%ebp
353		351
354	pusha	352	pusha
355		353
356	cld	354	cld
357	movl CNT(%ebp),%ecx	355	movl CNT(%ebp),%ecx
358	movl DST(%ebp),%edi	356	movl DST(%ebp),%edi
359	movl SRC(%ebp),%esi	357	movl SRC(%ebp),%esi
360		358
361	repe cmpsb %es:(%edi),%ds:(%esi)	359	repe cmpsb %es:(%edi),%ds:(%esi)
362	movl %ecx,(%ebp)	360	movl %ecx,(%ebp)
363		361
364	popa	362	popa
365		363
366	movl (%ebp),%eax # return value => %eax (zero on success)	364	movl (%ebp),%eax # return value => %eax (zero on success)
367	addl $4,%esp	365	addl $4,%esp
368	pop %ebp	366	pop %ebp
369		367
370	ret	368	ret
371		369
372		370
373	# THIS IS USERSPACE CODE	371	# THIS IS USERSPACE CODE
374	.global utext	372	.global utext
375	utext:	373	utext:
376	xor %ax,%ax;	374	xor %ax,%ax;
377	mov %ax,%ds;	375	mov %ax,%ds;
378	mov %ax,%es;	376	mov %ax,%es;
379	mov %ax,%fs;	377	mov %ax,%fs;
380	mov %ax,%gs;	378	mov %ax,%gs;
381	0:	379	0:
382	int $48	380	int $48
383	jmp 0b	381	jmp 0b
384	# not reached	382	# not reached
385	utext_end:	383	utext_end:
386		384
387	.data	385	.data
388	.global utext_size	386	.global utext_size
389	utext_size:	387	utext_size:
390	.long utext_end - utext	388	.long utext_end - utext
391		389
392		390
393	#.section K_DATA_START	391	#.section K_DATA_START
394	.global interrupt_handler_size	392	.global interrupt_handler_size
395		393
396	interrupt_handler_size: .long (h_end-h_start)/IDT_ITEMS	394	interrupt_handler_size: .long (h_end-h_start)/IDT_ITEMS
397		395

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(root)/SPARTAN/trunk/arch/ia32/src/asm.S – Rev 168 → 185