xref: /openbmc/linux/arch/m68k/kernel/sun3-head.S (revision 9cfc5c90)
1#include <linux/linkage.h>
2#include <linux/init.h>
3
4#include <asm/entry.h>
5#include <asm/page.h>
6#include <asm/contregs.h>
7#include <asm/sun3-head.h>
8
9PSL_HIGHIPL     = 0x2700
10NBSG            = 0x20000
11ICACHE_ONLY	= 0x00000009
12CACHES_OFF	= 0x00000008	| actually a clear and disable --m
13#define MAS_STACK INT_STACK
14ROOT_TABLE_SIZE = 128
15PAGESIZE	= 8192
16SUN3_INVALID_PMEG = 255
17.globl bootup_user_stack
18.globl bootup_kernel_stack
19.globl pg0
20.globl swapper_pg_dir
21.globl kernel_pmd_table
22.globl availmem
23.global m68k_pgtable_cachemode
24.global kpt
25| todo: all these should be in bss!
26swapper_pg_dir:                .skip 0x2000
27pg0:                           .skip 0x2000
28kernel_pmd_table:              .skip 0x2000
29
30.globl kernel_pg_dir
31.equ    kernel_pg_dir,kernel_pmd_table
32
33	__HEAD
34ENTRY(_stext)
35ENTRY(_start)
36
37/* Firstly, disable interrupts and set up function codes. */
38	movew	#PSL_HIGHIPL, %sr
39	moveq	#FC_CONTROL, %d0
40	movec	%d0, %sfc
41	movec	%d0, %dfc
42
43/* Make sure we're in context zero. */
44	moveq	#0, %d0
45	movsb	%d0, AC_CONTEXT
46
47/* map everything the bootloader left us into high memory, clean up the
48   excess later */
49	lea	(AC_SEGMAP+0),%a0
50	lea	(AC_SEGMAP+KERNBASE),%a1
511:
52	movsb	%a0@, %d1
53	movsb	%d1, %a1@
54	cmpib	#SUN3_INVALID_PMEG, %d1
55	beq	2f
56	addl	#NBSG,%a0
57	addl	#NBSG,%a1
58	jmp	1b
59
602:
61
62/* Disable caches and jump to high code. */
63	moveq	#ICACHE_ONLY,%d0	| Cache disabled until we're ready to enable it
64	movc	%d0, %cacr	|   is this the right value? (yes --m)
65	jmp	1f:l
66
67/* Following code executes at high addresses (0xE000xxx). */
681:	lea	init_task,%curptr			| get initial thread...
69	lea	init_thread_union+THREAD_SIZE,%sp	| ...and its stack.
70
71/* Point MSP at an invalid page to trap if it's used. --m */
72	movl	#(PAGESIZE),%d0
73	movc	%d0,%msp
74	moveq	#-1,%d0
75	movsb	%d0,(AC_SEGMAP+0x0)
76
77	jbsr	sun3_init
78
79	jbsr	base_trap_init
80
81        jbsr    start_kernel
82	trap	#15
83
84        .data
85        .even
86kpt:
87        .long 0
88availmem:
89        .long 0
90| todo: remove next two. --m
91is_medusa:
92        .long 0
93m68k_pgtable_cachemode:
94        .long 0
95
96