Root/arch/s390/kernel/head31.S

1/*
2 * arch/s390/kernel/head31.S
3 *
4 * Copyright (C) IBM Corp. 2005,2010
5 *
6 * Author(s): Hartmut Penner <hp@de.ibm.com>
7 * Martin Schwidefsky <schwidefsky@de.ibm.com>
8 * Rob van der Heij <rvdhei@iae.nl>
9 * Heiko Carstens <heiko.carstens@de.ibm.com>
10 *
11 */
12
13#include <linux/init.h>
14#include <asm/asm-offsets.h>
15#include <asm/thread_info.h>
16#include <asm/page.h>
17
18__HEAD
19    .globl startup_continue
20startup_continue:
21    basr %r13,0 # get base
22.LPG1:
23
24    l %r1,.Lbase_cc-.LPG1(%r13)
25    mvc 0(8,%r1),__LC_LAST_UPDATE_CLOCK
26    lctl %c0,%c15,.Lctl-.LPG1(%r13) # load control registers
27    l %r12,.Lparmaddr-.LPG1(%r13) # pointer to parameter area
28                    # move IPL device to lowcore
29#
30# Setup stack
31#
32    l %r15,.Linittu-.LPG1(%r13)
33    st %r15,__LC_THREAD_INFO # cache thread info in lowcore
34    mvc __LC_CURRENT(4),__TI_task(%r15)
35    ahi %r15,1<<(PAGE_SHIFT+THREAD_ORDER) # init_task_union+THREAD_SIZE
36    st %r15,__LC_KERNEL_STACK # set end of kernel stack
37    ahi %r15,-96
38#
39# Save ipl parameters, clear bss memory, initialize storage key for kernel pages,
40# and create a kernel NSS if the SAVESYS= parm is defined
41#
42    l %r14,.Lstartup_init-.LPG1(%r13)
43    basr %r14,%r14
44    lpsw .Lentry-.LPG1(13) # jump to _stext in primary-space,
45                    # virtual and never return ...
46    .align 8
47.Lentry:.long 0x00080000,0x80000000 + _stext
48.Lctl: .long 0x04b50002 # cr0: various things
49    .long 0 # cr1: primary space segment table
50    .long .Lduct # cr2: dispatchable unit control table
51    .long 0 # cr3: instruction authorization
52    .long 0 # cr4: instruction authorization
53    .long .Lduct # cr5: primary-aste origin
54    .long 0 # cr6: I/O interrupts
55    .long 0 # cr7: secondary space segment table
56    .long 0 # cr8: access registers translation
57    .long 0 # cr9: tracing off
58    .long 0 # cr10: tracing off
59    .long 0 # cr11: tracing off
60    .long 0 # cr12: tracing off
61    .long 0 # cr13: home space segment table
62    .long 0xc0000000 # cr14: machine check handling off
63    .long 0 # cr15: linkage stack operations
64.Lmchunk:.long memory_chunk
65.Lbss_bgn: .long __bss_start
66.Lbss_end: .long _end
67.Lparmaddr: .long PARMAREA
68.Linittu: .long init_thread_union
69.Lstartup_init:
70        .long startup_init
71    .align 64
72.Lduct: .long 0,0,0,0,.Lduald,0,0,0
73    .long 0,0,0,0,0,0,0,0
74    .align 128
75.Lduald:.rept 8
76    .long 0x80000000,0,0,0 # invalid access-list entries
77    .endr
78.Lbase_cc:
79    .long sched_clock_base_cc
80
81    .globl _ehead
82_ehead:
83
84#ifdef CONFIG_SHARED_KERNEL
85    .org 0x100000 - 0x11000 # head.o ends at 0x11000
86#endif
87
88#
89# startup-code, running in absolute addressing mode
90#
91    .globl _stext
92_stext: basr %r13,0 # get base
93.LPG3:
94# check control registers
95    stctl %c0,%c15,0(%r15)
96    oi 2(%r15),0x40 # enable sigp emergency signal
97    oi 0(%r15),0x10 # switch on low address protection
98    lctl %c0,%c15,0(%r15)
99
100#
101    lam 0,15,.Laregs-.LPG3(%r13) # load access regs needed by uaccess
102    l %r14,.Lstart-.LPG3(%r13)
103    basr %r14,%r14 # call start_kernel
104#
105# We returned from start_kernel ?!? PANIK
106#
107    basr %r13,0
108    lpsw .Ldw-.(%r13) # load disabled wait psw
109#
110    .align 8
111.Ldw: .long 0x000a0000,0x00000000
112.Lstart:.long start_kernel
113.Laregs:.long 0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0
114

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