Root/arch/s390/kernel/relocate_kernel64.S

1/*
2 * arch/s390/kernel/relocate_kernel64.S
3 *
4 * (C) Copyright IBM Corp. 2005
5 *
6 * Author(s): Rolf Adelsberger,
7 * Heiko Carstens <heiko.carstens@de.ibm.com>
8 *
9 */
10
11/*
12 * moves the new kernel to its destination...
13 * %r2 = pointer to first kimage_entry_t
14 * %r3 = start address - where to jump to after the job is done...
15 *
16 * %r5 will be used as temp. storage
17 * %r6 holds the destination address
18 * %r7 = PAGE_SIZE
19 * %r8 holds the source address
20 * %r9 = PAGE_SIZE
21 *
22 * 0xf000 is a page_mask
23 */
24
25    .text
26    .globl relocate_kernel
27    relocate_kernel:
28        basr %r13,0 # base address
29    .base:
30        stnsm sys_msk-.base(%r13),0xfb # disable DAT
31        stctg %c0,%c15,ctlregs-.base(%r13)
32        stmg %r0,%r15,gprregs-.base(%r13)
33        lghi %r0,3
34        sllg %r0,%r0,31
35        stg %r0,0x1d0(%r0)
36        la %r0,.back_pgm-.base(%r13)
37        stg %r0,0x1d8(%r0)
38        la %r1,load_psw-.base(%r13)
39        mvc 0(8,%r0),0(%r1)
40        la %r0,.back-.base(%r13)
41        st %r0,4(%r0)
42        oi 4(%r0),0x80
43        lghi %r0,0
44        diag %r0,%r0,0x308
45    .back:
46        lhi %r1,1 # mode 1 = esame
47        sigp %r1,%r0,0x12 # switch to esame mode
48        sam64 # switch to 64 bit addressing mode
49        basr %r13,0
50    .back_base:
51        oi have_diag308-.back_base(%r13),0x01
52        lctlg %c0,%c15,ctlregs-.back_base(%r13)
53        lmg %r0,%r15,gprregs-.back_base(%r13)
54        j .top
55    .back_pgm:
56        lmg %r0,%r15,gprregs-.base(%r13)
57    .top:
58        lghi %r7,4096 # load PAGE_SIZE in r7
59        lghi %r9,4096 # load PAGE_SIZE in r9
60        lg %r5,0(%r2) # read another word for indirection page
61        aghi %r2,8 # increment pointer
62        tml %r5,0x1 # is it a destination page?
63        je .indir_check # NO, goto "indir_check"
64        lgr %r6,%r5 # r6 = r5
65        nill %r6,0xf000 # mask it out and...
66        j .top # ...next iteration
67    .indir_check:
68        tml %r5,0x2 # is it a indirection page?
69        je .done_test # NO, goto "done_test"
70        nill %r5,0xf000 # YES, mask out,
71        lgr %r2,%r5 # move it into the right register,
72        j .top # and read next...
73    .done_test:
74        tml %r5,0x4 # is it the done indicator?
75        je .source_test # NO! Well, then it should be the source indicator...
76        j .done # ok, lets finish it here...
77    .source_test:
78        tml %r5,0x8 # it should be a source indicator...
79        je .top # NO, ignore it...
80        lgr %r8,%r5 # r8 = r5
81        nill %r8,0xf000 # masking
82    0: mvcle %r6,%r8,0x0 # copy PAGE_SIZE bytes from r8 to r6 - pad with 0
83        jo 0b
84        j .top
85    .done:
86        sgr %r0,%r0 # clear register r0
87        la %r4,load_psw-.base(%r13) # load psw-address into the register
88        o %r3,4(%r4) # or load address into psw
89        st %r3,4(%r4)
90        mvc 0(8,%r0),0(%r4) # copy psw to absolute address 0
91        tm have_diag308-.base(%r13),0x01
92        jno .no_diag308
93        diag %r0,%r0,0x308
94    .no_diag308:
95        sam31 # 31 bit mode
96        sr %r1,%r1 # erase register r1
97        sr %r2,%r2 # erase register r2
98        sigp %r1,%r2,0x12 # set cpuid to zero
99        lpsw 0 # hopefully start new kernel...
100
101        .align 8
102    load_psw:
103        .long 0x00080000,0x80000000
104    sys_msk:
105        .quad 0
106    ctlregs:
107        .rept 16
108        .quad 0
109        .endr
110    gprregs:
111        .rept 16
112        .quad 0
113        .endr
114    have_diag308:
115        .byte 0
116        .align 8
117    relocate_kernel_end:
118    .globl relocate_kernel_len
119    relocate_kernel_len:
120        .quad relocate_kernel_end - relocate_kernel
121

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