mes/lib/linux/arm-mes-gcc/_write.c

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/* -*-comment-start: "//";comment-end:""-*-
* GNU Mes --- Maxwell Equations of Software
* Copyright © 2016,2017,2019,2020 Jan (janneke) Nieuwenhuizen <janneke@gnu.org>
* Copyright © 2019,2020 Danny Milosavljevic <dannym@scratchpost.org>
*
* This file is part of GNU Mes.
*
* GNU Mes is free software; you can redistribute it and/or modify it
* under the terms of the GNU General Public License as published by
* the Free Software Foundation; either version 3 of the License, or (at
* your option) any later version.
*
* GNU Mes 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 General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with GNU Mes. If not, see <http://www.gnu.org/licenses/>.
*/
#include "mes/lib-mini.h"
// *INDENT-OFF*
#if !__TINYC__
#define SYS_write "0x04"
ssize_t
_write (int filedes, void const *buffer, size_t size)
{
long r;
asm (
"mov r7, $"SYS_write"\n\t"
"mov r0, %1\n\t"
"mov r1, %2\n\t"
"mov r3, %3\n\t"
"swi $0\n\t"
"mov %0, r0\n\t"
: "=r" (r)
: "r" (filedes), "r" (buffer), "r" (size)
: "r0", "r1", "r2", "r7"
);
return r;
}
#else //__TINYC__
#define SYS_write 0x04
ssize_t
_write (int filedes, void const *buffer, size_t size)
{
long r;
int c = SYS_write;
__asm__ (".int 0xe51b7008\n"); //ldr r7, [fp, #-8] ; <c>
__asm__ (".int 0xe59b000c\n"); //ldr r0, [fp, #12] ; filedes
__asm__ (".int 0xe59b1010\n"); //ldr r1, [fp, #16] ; buffer
__asm__ (".int 0xe59b2014\n"); //ldr r2, [fp, #20] ; size
__asm__ (".int 0xef000000\n"); //svc 0x00000000
__asm__ (".int 0xe50b0004\n"); //str r0, [fp, #-4]
return r;
}
#endif //__TINYC__
// *INDENT-ON*