entered into RCS

sysdeps/standalone/m68k/m68020/start.S

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+/* 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)