diff options
Diffstat (limited to 'sysdeps/standalone/m68k/m68020/start.S')
| -rw-r--r-- | sysdeps/standalone/m68k/m68020/start.S | 155 |
1 files changed, 155 insertions, 0 deletions
diff --git a/sysdeps/standalone/m68k/m68020/start.S b/sysdeps/standalone/m68k/m68020/start.S new file mode 100644 index 0000000000..cbabf5bf07 --- /dev/null +++ b/sysdeps/standalone/m68k/m68020/start.S @@ -0,0 +1,155 @@ +/* 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 | Default entry point + .globl _start | Default entry point + .globl M68Kvec | Vector Table + .globl _M68Kvec | Vector Table + +start: +_start: +M68Kvec: | standard location for vectors +_M68Kvec: | standard location for vectors + nop | for linkers with problem + | using location zero as entry + jmp around + .space 4088 | to avoid initial intr stack + | from 135BUG on MVME13? as entry + | and start code at 0x4000 +around: + move.w %sr,initial_sr | save initial values + movec %isp,%a0 + movel %a0,initial_isp + movec %usp,%a0 + movel %a0,initial_usp + movec %msp,%a0 + movel %a0,initial_msp + oriw #0x0700,%sr | INTERRUPTS OFF!!! + + + + | + | zero out uninitialized data area + | +zerobss: + moveal #end,%a0 | find end of .bss + moveal #_bss_start,%a1 | find beginning of .bss + movel #0,%d0 + +loop: movel #0,%a1@+ | to zero out uninitialized + cmpal %a0,%a1 + jlt loop | loop until _end reached + + movel #heap_size,__C_heap_size | set ___C_heap_size + movel #heap_memory,__C_heap_start | set ___C_heap_start + moveal #interrupt_stack_end,%a0 | set interrupt stack pointer + movec %a0,%isp + moveal #stack_end,%a0 | set master stack pointer + movec %a0,%msp + moveal #stack_end,%a6 | set base pointer + movw #0x3000,%sr | SUPV MODE,INTERRUPTS ON!!! + +#ifdef NEED_UNDERSCORES + jsr __Board_Initialize | initialize the board +#else + jsr _Board_Initialize | initialize the board +#endif + + move.l #0,%sp@- | envp = NULL + move.l #0,%sp@- | argv = NULL + move.l #0,%sp@- | argc = NULL +#ifdef NEED_UNDERSCORES + jsr ___libc_init | initialize the library and + | call main +#else + jsr __libc_init | initialize the library and + | call main +#endif + add.l #12,%sp + + move.l #0,%sp@- | argc = NULL + jsr __exit | call the Board specific exit + addq.l #4,%sp + + move.l initial_isp,%a0 | if __exit returns then we can + movec %a0,%isp | restore the initial values + move.l initial_usp,%a0 + movec %a0,%usp + move.l initial_msp,%a0 + movec %a0,%msp + move.w initial_sr,%sr + rts + + + .bss + +/* + * So initial stack registers and status register can be saved. + */ + +#define DECLARE_SPACE(_name,_space,_align) \ + .globl _name ; \ + .align _align ; \ +_name##: .space _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) + +DECLARE_U32(initial_isp) +DECLARE_U32(initial_msp) +DECLARE_U32(initial_usp) +DECLARE_U16(initial_sr) + +/* + * 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) + +DECLARE_SPACE(interrupt_stack_memory,0x1000,4) +DECLARE_LABEL(interrupt_stack_end) |