| 1 | ##============================================================================== |
|---|
| 2 | ## |
|---|
| 3 | ## crt0.S |
|---|
| 4 | ## |
|---|
| 5 | ## MN10300 startup code |
|---|
| 6 | ## |
|---|
| 7 | ##============================================================================== |
|---|
| 8 | ## |
|---|
| 9 | ## Copyright (c) 1995, 1996, 1997, 1998 Cygnus Solutions |
|---|
| 10 | ## |
|---|
| 11 | ## The authors hereby grant permission to use, copy, modify, distribute, |
|---|
| 12 | ## and license this software and its documentation for any purpose, provided |
|---|
| 13 | ## that existing copyright notices are retained in all copies and that this |
|---|
| 14 | ## notice is included verbatim in any distributions. No written agreement, |
|---|
| 15 | ## license, or royalty fee is required for any of the authorized uses. |
|---|
| 16 | ## Modifications to this software may be copyrighted by their authors |
|---|
| 17 | ## and need not follow the licensing terms described here, provided that |
|---|
| 18 | ## the new terms are clearly indicated on the first page of each file where |
|---|
| 19 | ## they apply. |
|---|
| 20 | ## |
|---|
| 21 | |
|---|
| 22 | ##------------------------------------------------------------------------------ |
|---|
| 23 | |
|---|
| 24 | .file "crt0.S" |
|---|
| 25 | |
|---|
| 26 | ##------------------------------------------------------------------------------ |
|---|
| 27 | ## Startup code |
|---|
| 28 | .section .text |
|---|
| 29 | .global _start |
|---|
| 30 | _start: |
|---|
| 31 | mov _stack-8,a0 # Load up the stack pointer |
|---|
| 32 | mov a0,sp |
|---|
| 33 | |
|---|
| 34 | mov _edata,a0 # Get the start/end of bss |
|---|
| 35 | mov _end,a1 |
|---|
| 36 | |
|---|
| 37 | cmp a0,a1 # If no bss, then do nothing |
|---|
| 38 | beq .L0 |
|---|
| 39 | |
|---|
| 40 | clr d0 # clear d0 |
|---|
| 41 | |
|---|
| 42 | .L1: |
|---|
| 43 | movbu d0,(a0) # Clear a byte and bump pointer |
|---|
| 44 | inc a0 |
|---|
| 45 | cmp a0,a1 |
|---|
| 46 | bne .L1 |
|---|
| 47 | |
|---|
| 48 | .L0: |
|---|
| 49 | call ___main,[],0 # Call __main to run ctors/dtors |
|---|
| 50 | clr d0 |
|---|
| 51 | clr d1 |
|---|
| 52 | mov d0,(4,sp) |
|---|
| 53 | call _main,[],0 # Call main program |
|---|
| 54 | call _exit,[],0 # All done, no need to return or |
|---|
| 55 | # deallocate our stack. |
|---|
| 56 | |
|---|
| 57 | .section .stack |
|---|
| 58 | _stack: .long 1 |
|---|
| 59 | |
|---|
| 60 | .section .data |
|---|
| 61 | .global ___dso_handle |
|---|
| 62 | .weak ___dso_handle |
|---|
| 63 | ___dso_handle: |
|---|
| 64 | .long 0 |
|---|
