forked from ariadne/libucontext
62 lines
1.8 KiB
ArmAsm
62 lines
1.8 KiB
ArmAsm
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/*
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* Copyright (c) 2018 William Pitcock <nenolod@dereferenced.org>
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*
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* Permission to use, copy, modify, and/or distribute this software for any
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* purpose with or without fee is hereby granted, provided that the above
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* copyright notice and this permission notice appear in all copies.
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*
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* This software is provided 'as is' and without any warranty, express or
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* implied. In no event shall the authors be liable for any damages arising
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* from the use of this software.
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*/
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#include "defs.h"
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.globl __swapcontext;
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__swapcontext:
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str xzr, [x0, #R0_OFFSET + (0 * REGSZ)]
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/* save GPRs */
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stp x2, x3, [x0, #R0_OFFSET + (2 * REGSZ)]
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stp x4, x5, [x0, #R0_OFFSET + (4 * REGSZ)]
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stp x6, x7, [x0, #R0_OFFSET + (6 * REGSZ)]
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stp x8, x9, [x0, #R0_OFFSET + (8 * REGSZ)]
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stp x10, x11, [x0, #R0_OFFSET + (10 * REGSZ)]
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stp x12, x13, [x0, #R0_OFFSET + (12 * REGSZ)]
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stp x14, x15, [x0, #R0_OFFSET + (14 * REGSZ)]
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stp x16, x17, [x0, #R0_OFFSET + (16 * REGSZ)]
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stp x18, x19, [x0, #R0_OFFSET + (18 * REGSZ)]
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stp x20, x21, [x0, #R0_OFFSET + (20 * REGSZ)]
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stp x22, x23, [x0, #R0_OFFSET + (22 * REGSZ)]
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stp x24, x25, [x0, #R0_OFFSET + (24 * REGSZ)]
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stp x26, x27, [x0, #R0_OFFSET + (26 * REGSZ)]
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stp x28, x29, [x0, #R0_OFFSET + (28 * REGSZ)]
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str x30, [x0, #R0_OFFSET + (30 * REGSZ)]
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/* save current program counter in link register */
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str x30, [x0, #PC_OFFSET]
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/* save current stack pointer */
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mov x2, sp
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str x2, [x0, #SP_OFFSET]
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/* save pstate */
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str xzr, [x0, #PSTATE_OFFSET]
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/* context to swap to is in x1 so... we move to x0 and call setcontext */
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/* store our link register in x28 */
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mov x28, x30
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/* move x1 to x0 and call setcontext */
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mov x0, x1
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bl __setcontext
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/* hmm, we came back here try to return */
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mov x30, x28
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ret
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.weak swapcontext;
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swapcontext = __swapcontext;
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