88 lines
		
	
	
		
			2.1 KiB
		
	
	
	
		
			C
		
	
	
	
			
		
		
	
	
			88 lines
		
	
	
		
			2.1 KiB
		
	
	
	
		
			C
		
	
	
	
| /* cygmon.c -- Glue code for linking apps to run on top of Cygmon.
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|  *
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|  * Copyright (c) 1998, 1999, 2000 Red Hat, Inc.
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|  *
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|  * The authors hereby grant permission to use, copy, modify, distribute,
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|  * and license this software and its documentation for any purpose, provided
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|  * that existing copyright notices are retained in all copies and that this
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|  * notice is included verbatim in any distributions. No written agreement,
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|  * license, or royalty fee is required for any of the authorized uses.
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|  * Modifications to this software may be copyrighted by their authors
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|  * and need not follow the licensing terms described here, provided that
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|  * the new terms are clearly indicated on the first page of each file where
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|  * they apply.
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|  */
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| 
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| #include "syscall.h"
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| 
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| int
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| write ( int file,
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|         char *buf,
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|         int nbytes)
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| {
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|   return sysCall(SYS_write, file, (unsigned long)buf, nbytes);
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| }
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| 
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| int
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| read (int file,
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|       char *buf,
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|       int nbytes)
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| {
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|   return sysCall(SYS_read, file, (unsigned long)buf, nbytes);
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| }
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| 
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| int
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| outbyte (unsigned char c)
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| {
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|   return sysCall(SYS_write, 0, (unsigned long)&c, 1);
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| }
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| 
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| unsigned char
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| inbyte (void)
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| {
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|   char c;
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|   sysCall(SYS_read, 0, (unsigned long)&c, 1);
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|   return c;
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| }
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| 
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| 
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| /* Structure filled in by get_mem_info.  Only the size field is
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|    actually used (by sbrk), so the others aren't even filled in.  */
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| struct s_mem
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| {
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|   unsigned int size;
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|   unsigned int icsize;
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|   unsigned int dcsize;
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| };
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| 
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| // Perform a system call.
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| // Unused parameters should be set to 0.
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| int sysCall(unsigned long func, unsigned long p1, unsigned long p2, unsigned long p3)
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| {
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|   int ret = 0;
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|   asm volatile ( "
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|           move $4, %1
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|           move $5, %2
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|           move $6, %3
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|           move $7, %4
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|           syscall 
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|           nop
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|           move %0, $2" : "=r"(ret) : "r"(func), "r"(p1), "r"(p2), "r"(p3));
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|   return ret;
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| }
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| 
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| // These need to be kept in sync with the definitions in Cygmon.
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| #define SYS_meminfo     1001
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| 
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| void *
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| get_mem_info (mem)
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|      struct s_mem *mem;
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| {
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|   unsigned long totmem = 0, topmem = 0;
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|   int numbanks;
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| 
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|   numbanks = sysCall(SYS_meminfo, (unsigned long)&totmem, (unsigned long)&topmem, 0);
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|   mem->size = totmem;
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|   return (void*)topmem;
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| }
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