newlib/libgloss/msp430/syscalls.S

74 lines
2.0 KiB
ArmAsm

/* Copyright (c) 2012, 2013 Red Hat, Inc. All rights reserved.
This copyrighted material is made available to anyone wishing to use, modify,
copy, or redistribute it subject to the terms and conditions of the BSD
License. This program is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY expressed or implied, including the implied warranties
of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. A copy of this license
is available at http://www.opensource.org/licenses. Any Red Hat trademarks that
are incorporated in the source code or documentation are not subject to the BSD
License and may only be used or replicated with the express permission of
Red Hat, Inc.
*/
/* Be wary: the lower N bits of the *address* of the function
determines the syscall used by the simulator. Thus, the addresses
listed here depend on the syscall numbers in ../syscalls.h. */
/* As per the MSP430x200 Family Users Guide, section 1.5, "An
instruction fetch from the address range 0x0000 - 0x01FF will reset
the device." We take advantage of that to do syscalls in the
simulator, by trying to execute specific addresses in that range
and letting the simulator catch them while simulating the CALL
instruction. In theory, this is an operation that the physical
hardware will never attempt to do, so it won't interfere with the
simulation's accuracy (i.e. we aren't abusing holes in the opcode
map, for example). */
#include "../syscall.h"
#include "memmodel.h"
.macro sc,a
sc2 \a,\a
.endm
.macro sc2,name,num
.weak \name
.global \name
\name = 0x180 + \num
.endm
#define SC(n) sc2 n,SYS_##n
sc2 _exit,SYS_exit
SC (exit)
SC (open)
SC (close)
SC (read)
/* SC (write)*/
SC (fstat)
SC (lseek)
SC (kill)
.weak isatty
.global isatty
isatty:
.weak _isatty
.global _isatty
_isatty:
MOV #1,R12
ret_
.weak getpid
.global getpid
getpid:
MOV #42,R12
ret_
.weak gettimeofday
.global gettimeofday
gettimeofday:
MOV #0,R12
ret_
.size gettimeofday , . - gettimeofday