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/* Copyright (C) 1992, 1997 Free Software Foundation, Inc.
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This file is part of the GNU C Library.
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Contributed by Brendan Kehoe (brendan@cs.widener.edu).
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Also hacked by Ian Lance Taylor (ian@airs.com).
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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, write to the Free
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Software Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA
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/* This function saves all the registers, calls the
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user function, and then executes a sigreturn system call. The
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sigreturn call wants the address of a sigcontext structure. This
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is all hideously system dependent and, for all intents and
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purposes, undocumented.
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When we enter here, a3 holds the user's signal handler. We are
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supposed to fill in the context given in a2, and then pass it and
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the first two arguments to the user's function. If the user's
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function returns, we execute a sigreturn system call.
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The sc_onstack, sc_mask and sc_pc elements of the context are
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already set by the kernel. For some reason we don't have to save
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the floating point state or the coprocessor state; the kernel may
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have saved them for us, or it doesn't use them. */
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/* Store zero and the asm temp reg. */
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/* Put v1 in sc_regs[3]. */
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/* Save the caller saved registers in sc_regs[8..15]. */
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/* Save the callee saved registers in sc_regs[16..23]. */
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/* Save the code generator registers in sc_regs[24] & sc_regs[25]. */
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/* Save the kernel temp regs in sc_regs[26] & sc_regs[27]. */
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/* Save the global pointer in sc_regs[28]. */
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/* ... and also the return address in sc_regs[31]. */
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/* Note: we don't save the stack pointer in sc_regs[29];
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instead, we use the one that was already there. */
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/* Save the floating pointer in sc_regs[30]. */
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/* Save the mul/div stuff in sc_mdlo and sc_mdhi. */
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/* Move the stack up six. This will save the context. */
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/* Call their handler with the signal, code, and context; note
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this will clobber the context. */
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/* When we come back, restore the context and pass it right
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on into sigreturn(). */
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/* Do a sigreturn syscall; this doesn't return. */