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161 lines
3.7 KiB
ArmAsm
161 lines
3.7 KiB
ArmAsm
/* Create new context.
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Copyright (C) 2005-2020 Free Software Foundation, Inc.
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This file is part of the GNU C Library.
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The GNU C Library is free software; you can redistribute it and/or
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modify it under the terms of the GNU Lesser General Public
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License as published by the Free Software Foundation; either
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version 2.1 of the License, or (at your option) any later version.
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The GNU C Library is distributed in the hope that it will be useful,
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but WITHOUT ANY WARRANTY; without even the implied warranty of
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MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
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Lesser General Public License for more details.
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You should have received a copy of the GNU Lesser General Public
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License along with the GNU C Library; if not, see
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<https://www.gnu.org/licenses/>. */
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#include <sysdep.h>
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#include <abort-instr.h>
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#include "ucontext_i.h"
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/* void __makecontext (ucontext_t *ucp, void (*func)(), int argc, ...);
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__makecontext sets up a stack and registers for context to run a given
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function. The registers are set up like this:
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r4-r7: parameters 1 to 4
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r8 : uc_link from ucontext structure
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pc : (*func) pointer
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pr : address of exitcode
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r15 : stack pointer for func. */
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.text
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.align 5
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ENTRY(__makecontext)
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mov #4, r3
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mov.l @(oSS_SP,r4), r1 /* r1 <- ucb->stack_base */
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mov.l @(oSS_SIZE,r4), r2 /* r2 <- ucb->stack_size */
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add r1, r2 /* r2 <- stack_top */
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cmp/gt r3, r6 /* argc > 4? */
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bf/s 1f
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shlr2 r2 /* r2 <- stack_top / 4 */
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sub r6, r2
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add r3, r2
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1:
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shll2 r2 /* r2 <- stack_top - ((argc > 4) ? 4 * (argc - 4) : 0 */
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mov #oR15, r0
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mov.l @(oLINK,r4), r1
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mov.l r2, @(r0,r4) /* ucp->r15 <- r2 */
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mov.l r1, @(oR8,r4) /* ucp->r8 <- ucp->uc_link */
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mov #oPC, r0
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mov.l r5, @(r0,r4) /* ucp->PC <- func */
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cmp/pl r6 /* argc > 0? */
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bf/s .L1
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dt r6
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mov.l r7, @(oR4,r4) /* ucp->r4 <- argv[0] */
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cmp/pl r6 /* argc > 1? */
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bf/s .L1
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dt r6
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mov.l @(0,r15), r1
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mov.l r1, @(oR5,r4) /* ucp->r5 <- argv[1] */
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cmp/pl r6 /* argc > 2? */
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bf/s .L1
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dt r6
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mov.l @(4,r15), r1
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mov.l r1, @(oR6,r4) /* ucp->r6 <- argv[2] */
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cmp/pl r6 /* argc > 3? */
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bf/s .L1
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dt r6
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mov.l @(8,r15), r1
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mov.l r1, @(oR7,r4) /* ucp->r7 <- argv[3] */
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mov #12,r0
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.L0: /* Save remaining argv[] on the stack. */
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cmp/pl r6
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bf/s .L1
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dt r6
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mov.l @(r0,r15), r1
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mov.l r1, @r2
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add #4, r0
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bra .L0
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add #4, r2
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.L1:
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#ifdef PIC
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mova .Lexitcode, r0
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#else
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mov.l .L2, r0
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#endif
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add #oPR, r4
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rts
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mov.l r0, @r4 /* ucp->pr <- exitcode */
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#ifndef PIC
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.align 2
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.L2:
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.long .Lexitcode
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#endif
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cfi_endproc
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.align 5
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cfi_startproc
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.Lexitcode:
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#ifdef PIC
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mov.l r12, @-r15
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cfi_adjust_cfa_offset (4)
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cfi_rel_offset (r12, 0)
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mova .Lgot, r0
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mov.l .Lgot, r12
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add r0, r12
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#endif
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tst r8, r8 /* ucb->uc_link == NULL? */
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bt/s 2f
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mov r8, r4 /* r4 <- ucb->uc_link */
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mov.l .Lsetcontext, r1
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sts.l pr, @-r15
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cfi_adjust_cfa_offset (4)
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cfi_rel_offset (pr, 0)
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#ifdef PIC
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bsrf r1
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.LPCS0:
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nop
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#else
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jsr @r1
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nop
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#endif
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/* Restore to keep CFI/CFA balanced. */
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lds.l @r15+, pr
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cfi_adjust_cfa_offset (-4)
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cfi_restore (pr)
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/* If this returns (which can happen if the syscall fails) we'll exit
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the program with the return error value (-1). */
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mov r0, r4
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2:
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mov.l .Lexit, r1
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#ifdef PIC
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add r12, r1
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#endif
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jsr @r1
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nop
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/* The 'exit' call should never return. In case it does cause the
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process to terminate. */
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ABORT_INSTRUCTION_ASM
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.align 2
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#ifdef PIC
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.Lgot:
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.long _GLOBAL_OFFSET_TABLE_
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.Lsetcontext:
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.long __setcontext@PLT-(.LPCS0+2-(.))
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.Lexit:
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.long HIDDEN_JUMPTARGET(exit)@GOTOFF
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#else
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.Lsetcontext:
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.long __setcontext
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.Lexit:
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.long HIDDEN_JUMPTARGET(exit)
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#endif
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PSEUDO_END(__makecontext)
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weak_alias (__makecontext, makecontext)
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