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Diffstat (limited to 'sysdeps/standalone/i960/start.S')
| -rw-r--r-- | sysdeps/standalone/i960/start.S | 137 |
1 files changed, 137 insertions, 0 deletions
diff --git a/sysdeps/standalone/i960/start.S b/sysdeps/standalone/i960/start.S new file mode 100644 index 0000000000..c14449d3ff --- /dev/null +++ b/sysdeps/standalone/i960/start.S @@ -0,0 +1,137 @@ +/* Copyright (C) 1994 Free Software Foundation, Inc. + Contributed by Joel Sherrill (jsherril@redstone-emh2.army.mil), + On-Line Applications Research Corporation. + +This file is part of the GNU C Library. + +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. */ + +/* entry.s + * + * This file contains the entry point for the application. + * The name of this entry point is compiler dependent. + * It jumps to the BSP which is responsible for performing + * all initialization. + * + */ + + .text + .globl start # GNU960 default entry point + +start: + mov 3, r12 + modpc r12, r12, r12 # enable tracing/trace faults + mov g5, g5 # NOP + mov 0, g14 # initialize constant for C + + /* + * zero out uninitialized data area + */ +zerobss: + lda _end, r4 /* find end of .bss */ + lda _bss_start, r5 /* find beginning of .bss */ + ldconst 0, r6 + +loop: st r6, (r5) /* to zero out uninitialized */ + addo 4, r5, r5 /* data area */ + cmpobl r5, r4, loop /* loop until _end reached */ + + + lda heap_memory, r12 /* tell C lib where heap is */ + st r12,___C_heap_start + lda heap_size, r12 /* tell C lib how big heap is */ + st r12,___C_heap_size + lda stack_memory,r12 /* set up stack pointer: */ + mov r12, sp + mov 0, g14 /* initialize constant for C */ + + call init_frames + ret /* return to monitor */ + +init_frames: + ldconst 0x3b001000, g0 + ldconst 0x00009107, g1 + modac g1, g0, g0 /* set AC controls */ + + /* + * Call application mainline. + * Someday, real values of argc and argv will be set up. + * For now, they are set to 0. + */ + + callx __Board_Initialize /* Initialize the board */ + + ldconst 0,g0 + ldconst 0,g1 + ldconst 0,g2 + callx ___libc_init /* initialize the library and */ + /* call main */ + /* + * if we return from main, we have "fallen" off the end + * of the program, therefore status is 0 + * so move 0 to g0 (exit parameter) + */ + + mov 0, g0 + callx __exit + ret + + +/* + * Data Declarations. Start with a macro which helps declare space. + */ + +#define DECLARE_SPACE(_name,_space,_align) \ + .globl _name ; \ + .align _align ; \ +.comm _name##,_space + +#define DECLARE_LABEL(_name) \ + .globl _name ; \ +_name##: + +#define DECLARE_PTR(_name) DECLARE_SPACE(_name,4,2) +#define DECLARE_U32(_name) DECLARE_SPACE(_name,4,2) +#define DECLARE_U16(_name) DECLARE_SPACE(_name,2,1) + +/* + * Require environment stuff + */ + +DECLARE_LABEL(_environ) +DECLARE_PTR(environ) + +DECLARE_LABEL(_errno) +DECLARE_U32(errno) + +/* + * Stack Size and Space + */ + + .set stack_size, 0x20000 + +DECLARE_SPACE(stack_memory,stack_size,4) +DECLARE_LABEL(stack_end) + +/* + * Heap Size and Space + */ + + .set heap_size, 0x20000 + +DECLARE_SPACE(heap_memory,heap_size,4) +DECLARE_LABEL(heap_end) + |