127 lines
4.8 KiB
ArmAsm
127 lines
4.8 KiB
ArmAsm
/*
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Copyright Oliver Kowalke 2009.
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Distributed under the Boost Software License, Version 1.0.
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(See accompanying file LICENSE_1_0.txt or copy at
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http://www.boost.org/LICENSE_1_0.txt)
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*/
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/*******************************************************
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* *
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* ------------------------------------------------- *
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* | 0 | 1 | 2 | 3 | 4 | 5 | 6 | 7 | *
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* ------------------------------------------------- *
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* | 0 | 4 | 8 | 12 | 16 | 20 | 24 | 28 | *
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* ------------------------------------------------- *
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* | TOC | R14 | R15 | R16 | *
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* ------------------------------------------------- *
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* ------------------------------------------------- *
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* | 8 | 9 | 10 | 11 | 12 | 13 | 14 | 15 | *
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* ------------------------------------------------- *
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* | 32 | 36 | 40 | 44 | 48 | 52 | 56 | 60 | *
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* ------------------------------------------------- *
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* | R17 | R18 | R19 | R20 | *
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* ------------------------------------------------- *
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* ------------------------------------------------- *
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* | 16 | 17 | 18 | 19 | 20 | 21 | 22 | 23 | *
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* ------------------------------------------------- *
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* | 64 | 68 | 72 | 76 | 80 | 84 | 88 | 92 | *
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* ------------------------------------------------- *
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* | R21 | R22 | R23 | R24 | *
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* ------------------------------------------------- *
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* ------------------------------------------------- *
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* | 24 | 25 | 26 | 27 | 28 | 29 | 30 | 31 | *
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* ------------------------------------------------- *
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* | 96 | 100 | 104 | 108 | 112 | 116 | 120 | 124 | *
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* ------------------------------------------------- *
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* | R25 | R26 | R27 | R28 | *
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* ------------------------------------------------- *
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* ------------------------------------------------- *
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* | 32 | 33 | 34 | 35 | 36 | 37 | 38 | 39 | *
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* ------------------------------------------------- *
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* | 128 | 132 | 136 | 140 | 144 | 148 | 152 | 156 | *
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* ------------------------------------------------- *
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* | R29 | R30 | R31 | hidden | *
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* ------------------------------------------------- *
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* ------------------------------------------------- *
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* | 40 | 41 | 42 | 43 | 44 | 45 | 46 | 47 | *
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* ------------------------------------------------- *
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* | 160 | 164 | 168 | 172 | 176 | 180 | 184 | 188 | *
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* ------------------------------------------------- *
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* | CR | LR | PC | back-chain| *
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* ------------------------------------------------- *
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* ------------------------------------------------- *
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* | 48 | 49 | 50 | 51 | 52 | 53 | 54 | 55 | *
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* ------------------------------------------------- *
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* | 192 | 196 | 200 | 204 | 208 | 212 | 216 | 220 | *
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* ------------------------------------------------- *
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* | cr saved | lr saved | compiler | linker | *
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* ------------------------------------------------- *
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* ------------------------------------------------- *
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* | 56 | 57 | 58 | 59 | 60 | 61 | 62 | 63 | *
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* ------------------------------------------------- *
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* | 224 | 228 | 232 | 236 | 240 | 244 | 248 | 252 | *
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* ------------------------------------------------- *
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* | TOC saved | FCTX | DATA | | *
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* ------------------------------------------------- *
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* *
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.text
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.globl _make_fcontext
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_make_fcontext:
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; save return address into R6
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mflr r6
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; first arg of make_fcontext() == top address of context-function
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; shift address in R3 to lower 16 byte boundary
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clrrwi r3, r3, 4
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; reserve space for context-data on context-stack
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; including 64 byte of linkage + parameter area (R1 16 == 0)
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subi r3, r3, 248
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; third arg of make_fcontext() == address of context-function
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stw r5, 176(r3)
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; set back-chain to zero
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li %r0, 0
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std %r0, 184(%r3)
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; compute address of returned transfer_t
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addi %r0, %r3, 232
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mr %r4, %r0
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std %r4, 152(%r3)
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; load LR
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mflr r0
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; jump to label 1
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bl l1
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l1:
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; load LR into R4
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mflr r4
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; compute abs address of label finish
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addi r4, r4, lo16((finish - .) + 4)
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; restore LR
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mtlr r0
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; save address of finish as return-address for context-function
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; will be entered after context-function returns
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std r4, 168(r3)
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; restore return address from R6
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mtlr r6
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blr ; return pointer to context-data
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finish:
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; save return address into R0
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mflr r0
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; save return address on stack, set up stack frame
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stw r0, 8(r1)
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; allocate stack space, R1 16 == 0
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stwu r1, -32(r1)
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; set return value to zero
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li r3, 0
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; exit application
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bl __exit
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nop
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