diff options
Diffstat (limited to 'sysdeps/unix/bsd/ultrix4/mips/__handler.S')
| -rw-r--r-- | sysdeps/unix/bsd/ultrix4/mips/__handler.S | 113 |
1 files changed, 113 insertions, 0 deletions
diff --git a/sysdeps/unix/bsd/ultrix4/mips/__handler.S b/sysdeps/unix/bsd/ultrix4/mips/__handler.S new file mode 100644 index 0000000000..3ea697c5a0 --- /dev/null +++ b/sysdeps/unix/bsd/ultrix4/mips/__handler.S @@ -0,0 +1,113 @@ +/* Copyright (C) 1992 Free Software Foundation, Inc. + Contributed by Brendan Kehoe (brendan@zen.org). + Also hacked by Ian Lance Taylor (ian@airs.com). + +The GNU C Library is free software; you can redistribute it and/or +modify it under the terms of the GNU Library General Public License as +published by the Free Software Foundation; either version 2 of the +License, or (at your option) any later version. + +The GNU C Library is distributed in the hope that it will be useful, +but WITHOUT ANY WARRANTY; without even the implied warranty of +MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU +Library General Public License for more details. + +You should have received a copy of the GNU Library General Public +License along with the GNU C Library; see the file COPYING.LIB. If +not, write to the Free Software Foundation, Inc., 675 Mass Ave, +Cambridge, MA 02139, USA. */ + +#include <sysdep.h> + +/* This function saves all the registers, calls the + user function, and then executes a sigreturn system call. The + sigreturn call wants the address of a sigcontext structure. This + is all hideously system dependent and, for all intents and + purposes, undocumented. + + When we enter here, a3 holds the user's signal handler. We are + supposed to fill in the context given in a2, and then pass it and + the first two arguments to the user's function. If the user's + function returns, we execute a sigreturn system call. + + The sc_onstack, sc_mask and sc_pc elements of the context are + already set by the kernel. For some reason we don't have to save + the floating point state or the coprocessor state; the kernel may + have saved them for us, or it doesn't use them. */ + +.set noat +ENTRY (__handler) + /* Store zero and the asm temp reg. */ + sw $0, 12(a2) + sw AT, 16(a2) + + /* Put v1 in sc_regs[3]. */ + sw v1, 24(a2) + + /* Save the caller saved registers in sc_regs[8..15]. */ + sw t0, 44(a2) + sw t1, 48(a2) + sw t2, 52(a2) + sw t3, 56(a2) + sw t4, 60(a2) + sw t5, 64(a2) + sw t6, 68(a2) + sw t7, 72(a2) + + /* Save the callee saved registers in sc_regs[16..23]. */ + sw s0, 76(a2) + sw s1, 80(a2) + sw s2, 84(a2) + sw s3, 88(a2) + sw s4, 92(a2) + sw s5, 96(a2) + sw s6, 100(a2) + sw s7, 104(a2) + + /* Save the code generator registers in sc_regs[24] & sc_regs[25]. */ + sw t8, 108(a2) + sw t9, 112(a2) + + /* Save the kernel temp regs in sc_regs[26] & sc_regs[27]. */ + sw k0, 116(a2) + sw k1, 120(a2) + + /* Save the global pointer in sc_regs[28]. */ + sw gp, 124(a2) + + /* ... and also the return address in sc_regs[31]. */ + sw ra, 136(a2) + + /* Note: we don't save the stack pointer in sc_regs[29]; + instead, we use the one that was already there. */ +#if 0 + sw sp, 128(a2) +#endif + + /* Save the floating pointer in sc_regs[30]. */ + sw $fp, 132(a2) + + /* Save the mul/div stuff in sc_mdlo and sc_mdhi. */ + mflo t0 + sw t0, 140(a2) + mfhi t0 + sw t0, 144(a2) + + /* Move the stack up four. This will save the context. */ + addu sp, sp, -32 + sw a2, 16(sp) + + /* Call their handler with the signal, code, and context; note + this will clobber the context. */ + .set noreorder + jal ra, a3 + nop + .set reorder + + /* When we come back, restore the context and pass it right + on into sigreturn(). */ + lw a0, 16(sp) + + /* Do a sigreturn syscall; this doesn't return. */ + la v0, __sigreturn + jal ra, v0 |