WebSVN – HelenOS-historic – Diff – /kernel/trunk/arch/ppc32/src/start.S


#
# Copyright (C) 2005 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.
#
 
#include <arch/asm/regname.h>
#include <arch/asm/spr.h>
 
.section K_TEXT_START
 
.global kernel_image_start
 
.org 0x0
/* 256 bytes of some data */
/* exception table - must use 'ba' instructions for branches,
 * because it is elsewhere than the linker thinks
 */
.space 4096
 
kernel_image_start:
	/* Initialize OFW, might be needed before relocate_kernel? */
	lis r4, ofw@ha
	addi r4, r4, ofw@l
	stw r5, 0(r4)
	
	bl ofw_init
	bl preboot_read_config
 
	bl relocate_kernel
__after_reloc:
	/* Set stack to some more meaningful value */
	/* TODO: This is hardcoded for PearPC, must be changed later */
	lis r1, 0x70
	b main_bsp
	
relocate_kernel:
	/* TODO: We _know_ that pearpc loads it to 8MB, and
	 * but it should be really generic
	 */
	lis r4, 0x80 /* r4 is where data was loaded - 8MB */
	
	bl to_real_mode
	/* Now we are in real mode, copy first block and jump to it,
	 * we are running in the loaded kernel now
	 * We still have in r3 physical load kernel address
	 */
	
	b __after_reloc /* We know in pearpc we are ok, so return,
	                 * otherwise we should relocate kernel
		         * here
	                 */
 
	
 
	
/* Turn off page translation
 * - assume that physical-loaded address is in r4
 */
to_real_mode:
	mflr r0
	
	lis   r5, ktext_start@ha // Expected start of kernel
	addi r5, r5, ktext_start@l
	
	add  r0, r4, r0  	
	sub  r0, r0, r5         // r0 now contains physical return address
	
	mfmsr r3
	andis. r3, r3, (~MSR_DR | MSR_IR) >> 16
	mtspr SPRN_SRR0, r0
	mtspr SPRN_SRR1, r3
	sync 			// Really needed? RFI should do it as well?
	RFI
 
 

Rev 843	Rev 845
1	#	1	#
2	# Copyright (C) 2005 Jakub Jermar	2	# Copyright (C) 2005 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	#include <arch/asm/macro.h>	29	#include <arch/asm/regname.h>
30	#include <arch/asm/spr.h>	30	#include <arch/asm/spr.h>
31		31
32	.section K_TEXT_START	32	.section K_TEXT_START
33		33
34	.global kernel_image_start	34	.global kernel_image_start
35		35
36	.org 0x0	36	.org 0x0
37	/* 256 bytes of some data */	37	/* 256 bytes of some data */
38	/* exception table - must use 'ba' instructions for branches,	38	/* exception table - must use 'ba' instructions for branches,
39	* because it is elsewhere than the linker thinks	39	* because it is elsewhere than the linker thinks
40	*/	40	*/
41	.space 4096	41	.space 4096
42		42
43	kernel_image_start:	43	kernel_image_start:
44	/* Initialize OFW, might be needed before relocate_kernel? */	44	/* Initialize OFW, might be needed before relocate_kernel? */
45	lis r4, ofw@ha	45	lis r4, ofw@ha
46	addi r4, r4, ofw@l	46	addi r4, r4, ofw@l
47	stw r5, 0(r4)	47	stw r5, 0(r4)
48		48
49	bl ofw_init	49	bl ofw_init
50	bl preboot_read_config	50	bl preboot_read_config
51		51
52	bl relocate_kernel	52	bl relocate_kernel
53	__after_reloc:	53	__after_reloc:
54	/* Set stack to some more meaningful value */	54	/* Set stack to some more meaningful value */
55	/* TODO: This is hardcoded for PearPC, must be changed later */	55	/* TODO: This is hardcoded for PearPC, must be changed later */
56	lis r1, 0x70	56	lis r1, 0x70
57	b main_bsp	57	b main_bsp
58		58
59	relocate_kernel:	59	relocate_kernel:
60	/* TODO: We _know_ that pearpc loads it to 8MB, and	60	/* TODO: We _know_ that pearpc loads it to 8MB, and
61	* but it should be really generic	61	* but it should be really generic
62	*/	62	*/
63	lis r4, 0x80 /* r4 is where data was loaded - 8MB */	63	lis r4, 0x80 /* r4 is where data was loaded - 8MB */
64		64
65	bl to_real_mode	65	bl to_real_mode
66	/* Now we are in real mode, copy first block and jump to it,	66	/* Now we are in real mode, copy first block and jump to it,
67	* we are running in the loaded kernel now	67	* we are running in the loaded kernel now
68	* We still have in r3 physical load kernel address	68	* We still have in r3 physical load kernel address
69	*/	69	*/
70		70
71	b __after_reloc /* We know in pearpc we are ok, so return,	71	b __after_reloc /* We know in pearpc we are ok, so return,
72	* otherwise we should relocate kernel	72	* otherwise we should relocate kernel
73	* here	73	* here
74	*/	74	*/
75		75
76		76
77		77
78		78
79	/* Turn off page translation	79	/* Turn off page translation
80	* - assume that physical-loaded address is in r4	80	* - assume that physical-loaded address is in r4
81	*/	81	*/
82	to_real_mode:	82	to_real_mode:
83	mflr r0	83	mflr r0
84		84
85	lis r5, ktext_start@ha // Expected start of kernel	85	lis r5, ktext_start@ha // Expected start of kernel
86	addi r5, r5, ktext_start@l	86	addi r5, r5, ktext_start@l
87		87
88	add r0, r4, r0	88	add r0, r4, r0
89	sub r0, r0, r5 // r0 now contains physical return address	89	sub r0, r0, r5 // r0 now contains physical return address
90		90
91	mfmsr r3	91	mfmsr r3
92	andis. r3, r3, (~MSR_DR \| MSR_IR) >> 16	92	andis. r3, r3, (~MSR_DR \| MSR_IR) >> 16
93	mtspr SPRN_SRR0, r0	93	mtspr SPRN_SRR0, r0
94	mtspr SPRN_SRR1, r3	94	mtspr SPRN_SRR1, r3
95	sync // Really needed? RFI should do it as well?	95	sync // Really needed? RFI should do it as well?
96	RFI	96	RFI
97		97
98		98

Subversion Repositories HelenOS-historic

(root)/kernel/trunk/arch/ppc32/src/start.S – Rev 843 → 845