78 lines
2.5 KiB
NASM
78 lines
2.5 KiB
NASM
;/*
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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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; * | 0x0 | 0x4 | 0x8 | 0xc | 0x10| 0x14| 0x18| 0x1c| *
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; * ------------------------------------------------- *
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; * |deall|limit| base|hiddn| v1 | v2 | v3 | v4 | *
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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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; * | 0x20| 0x24| 0x28| 0x2c| 0x30| 0x34| 0x38| 0x3c| *
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; * ------------------------------------------------- *
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; * | v5 | v6 | v7 | v8 | lr | pc | FCTX| DATA| *
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; * ------------------------------------------------- *
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; * *
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; *******************************************************
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AREA |.text|, CODE
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ALIGN 4
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EXPORT ostd_make_fcontext
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IMPORT _exit
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ostd_make_fcontext PROC
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; first arg of ostd_make_fcontext() == top of context-stack
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; save top of context-stack (base) A4
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mov a4, a1
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; shift address in A1 to lower 16 byte boundary
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bic a1, a1, #0x0f
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; reserve space for context-data on context-stack
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sub a1, a1, #0x48
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; save top address of context_stack as 'base'
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str a4, [a1, #0x8]
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; second arg of ostd_make_fcontext() == size of context-stack
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; compute bottom address of context-stack (limit)
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sub a4, a4, a2
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; save bottom address of context-stack as 'limit'
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str a4, [a1, #0x4]
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; save bottom address of context-stack as 'dealloction stack'
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str a4, [a1, #0x0]
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; third arg of ostd_make_fcontext() == address of context-function
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str a3, [a1, #0x34]
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; compute address of returned transfer_t
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add a2, a1, #0x38
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mov a3, a2
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str a3, [a1, #0xc]
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; compute abs address of label finish
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adr a2, finish
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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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str a2, [a1, #0x30]
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bx lr ; return pointer to context-data
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finish
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; exit code is zero
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mov a1, #0
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; exit application
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bl _exit
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ENDP
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END
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