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Diffstat (limited to 'gcc-4.9/libgcc/config/mmix/crti.S')
| -rw-r--r-- | gcc-4.9/libgcc/config/mmix/crti.S | 152 |
1 files changed, 152 insertions, 0 deletions
diff --git a/gcc-4.9/libgcc/config/mmix/crti.S b/gcc-4.9/libgcc/config/mmix/crti.S new file mode 100644 index 000000000..82ffa6de8 --- /dev/null +++ b/gcc-4.9/libgcc/config/mmix/crti.S @@ -0,0 +1,152 @@ +/* Copyright (C) 2001-2014 Free Software Foundation, Inc. + Contributed by Hans-Peter Nilsson <hp@bitrange.com> + +This file is free software; you can redistribute it and/or modify it +under the terms of the GNU General Public License as published by the +Free Software Foundation; either version 3, or (at your option) any +later version. + +This file 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 +General Public License for more details. + +Under Section 7 of GPL version 3, you are granted additional +permissions described in the GCC Runtime Library Exception, version +3.1, as published by the Free Software Foundation. + +You should have received a copy of the GNU General Public License and +a copy of the GCC Runtime Library Exception along with this program; +see the files COPYING3 and COPYING.RUNTIME respectively. If not, see +<http://www.gnu.org/licenses/>. */ + +% This is the crt0 equivalent for mmix-knuth-mmixware, for setting up +% things for compiler-generated assembly-code and for setting up things +% between where the simulator calls and main, and shutting things down on +% the way back. There's an actual crt0.o elsewhere, but that's a dummy. + +% This file and the GCC output are supposed to be *reasonably* +% mmixal-compatible to enable people to re-use output with Knuth's mmixal. +% However, forward references are used more freely: we are using the +% binutils tools. Users of mmixal beware; you will sometimes have to +% re-order things or use temporary variables. + +% Users of mmixal will want to set up 8H and 9H to be .text and .data +% respectively, so the compiler can switch between them pretending they're +% segments. + +% This little treasure (some contents) is required so the 32 lowest +% address bits of user data will not be zero. Because of truncation, +% that would cause testcase gcc.c-torture/execute/980701-1.c to +% incorrectly fail. + + .data ! mmixal:= 8H LOC Data_Segment + .p2align 3 +dstart OCTA 2009 + + .text ! mmixal:= 9H LOC 8B; LOC #100 + .global Main + +% The __Stack_start symbol is provided by the link script. +stackpp OCTA __Stack_start +crtstxt OCTA _init % Assumed to be the lowest executed address. + OCTA __etext % Assumed to be beyond the highest executed address. + +crtsdat OCTA dstart % Assumed to be the lowest accessed address. + OCTA _end % Assumed to be beyond the highest accessed address. + +% "Main" is the magic symbol the simulator jumps to. We want to go +% on to "main". +% We need to set rG explicitly to avoid hard-to-debug situations. +Main SETL $255,32 + PUT rG,$255 + +% Make sure we have valid memory for addresses in .text and .data (and +% .bss, but we include this in .data), for the benefit of mmo-using +% simulators that require validation of addresses for which contents +% is not present. Due to its implicit-zero nature, zeros in contents +% may be left out in the mmo format, but we don't know the boundaries +% of those zero-chunks; for mmo files from binutils, they correspond +% to the beginning and end of sections in objects before linking. We +% validate the contents by executing PRELD (0; one byte) on each +% 2048-byte-boundary of our .text .data, and we assume this size +% matches the magic lowest-denominator chunk-size for all +% validation-requiring simulators. The effect of the PRELD (any size) +% is assumed to be the same as initial loading of the contents, as +% long as the PRELD happens before the first PUSHJ/PUSHGO. If it +% happens after that, we'll need to distinguish between +% access-for-execution and read/write access. + + GETA $255,crtstxt + LDOU $2,$255,0 + ANDNL $2,#7ff % Align the start at a 2048-boundary. + LDOU $3,$255,8 + SETL $4,2048 +0H PRELD 0,$2,0 + ADDU $2,$2,$4 + CMP $255,$2,$3 + BN $255,0B + + GETA $255,crtsdat + LDOU $2,$255,0 + ANDNL $2,#7ff + LDOU $3,$255,8 +0H PRELD 0,$2,0 + ADDU $2,$2,$4 + CMP $255,$2,$3 + BN $255,0B + +% Initialize the stack pointer. It is supposedly made a global +% zero-initialized (allowed to change) register in crtn.S; we use the +% explicit number. + GETA $255,stackpp + LDOU $254,$255,0 + + PUSHJ $2,_init + +#ifdef __MMIX_ABI_GNU__ +% Copy argc and argv from their initial position to argument registers +% where necessary. + SET $231,$0 + SET $232,$1 +#else +% For the mmixware ABI, we need to move arguments. The return value will +% appear in $0. + SET $2,$1 + SET $1,$0 +#endif + + PUSHJ $0,main + JMP exit + +% Provide the first part of _init and _fini. Save the return address on the +% register stack. We eventually ignore the return address of these +% PUSHJ:s, so it doesn't matter that whether .init and .fini code calls +% functions or where they store rJ. We shouldn't get there, so die +% (TRAP Halt) if that happens. + + .section .init,"ax",@progbits + .global _init +_init: + GET $0,:rJ + PUSHJ $1,0F + SETL $255,255 + TRAP 0,0,0 +0H IS @ + +% Register _fini to be executed as the last atexit function. +#ifdef __MMIX_ABI_GNU__ + GETA $231,_fini +#else + GETA $1,_fini +#endif + PUSHJ $0,atexit + + .section .fini,"ax",@progbits + .global _fini +_fini: + GET $0,:rJ + PUSHJ $1,0F + SETL $255,255 + TRAP 0,0,0 +0H IS @ |