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/* SPDX-License-Identifier: LGPL-2.1 OR MIT */
/*
* s390 specific definitions for NOLIBC
*/
#ifndef _NOLIBC_ARCH_S390_H
#define _NOLIBC_ARCH_S390_H
#include <asm/signal.h>
#include <asm/unistd.h>
#include "compiler.h"
#include "crt.h"
/* Syscalls for s390:
* - registers are 64-bit
* - syscall number is passed in r1
* - arguments are in r2-r7
* - the system call is performed by calling the svc instruction
* - syscall return value is in r2
* - r1 and r2 are clobbered, others are preserved.
*
* Link s390 ABI: https://github.com/IBM/s390x-abi
*
*/
#define my_syscall0(num) \
({ \
register long _num __asm__ ("1") = (num); \
register long _rc __asm__ ("2"); \
\
__asm__ volatile ( \
"svc 0\n" \
: "=d"(_rc) \
: "d"(_num) \
: "memory", "cc" \
); \
_rc; \
})
#define my_syscall1(num, arg1) \
({ \
register long _num __asm__ ("1") = (num); \
register long _arg1 __asm__ ("2") = (long)(arg1); \
\
__asm__ volatile ( \
"svc 0\n" \
: "+d"(_arg1) \
: "d"(_num) \
: "memory", "cc" \
); \
_arg1; \
})
#define my_syscall2(num, arg1, arg2) \
({ \
register long _num __asm__ ("1") = (num); \
register long _arg1 __asm__ ("2") = (long)(arg1); \
register long _arg2 __asm__ ("3") = (long)(arg2); \
\
__asm__ volatile ( \
"svc 0\n" \
: "+d"(_arg1) \
: "d"(_arg2), "d"(_num) \
: "memory", "cc" \
); \
_arg1; \
})
#define my_syscall3(num, arg1, arg2, arg3) \
({ \
register long _num __asm__ ("1") = (num); \
register long _arg1 __asm__ ("2") = (long)(arg1); \
register long _arg2 __asm__ ("3") = (long)(arg2); \
register long _arg3 __asm__ ("4") = (long)(arg3); \
\
__asm__ volatile ( \
"svc 0\n" \
: "+d"(_arg1) \
: "d"(_arg2), "d"(_arg3), "d"(_num) \
: "memory", "cc" \
); \
_arg1; \
})
#define my_syscall4(num, arg1, arg2, arg3, arg4) \
({ \
register long _num __asm__ ("1") = (num); \
register long _arg1 __asm__ ("2") = (long)(arg1); \
register long _arg2 __asm__ ("3") = (long)(arg2); \
register long _arg3 __asm__ ("4") = (long)(arg3); \
register long _arg4 __asm__ ("5") = (long)(arg4); \
\
__asm__ volatile ( \
"svc 0\n" \
: "+d"(_arg1) \
: "d"(_arg2), "d"(_arg3), "d"(_arg4), "d"(_num) \
: "memory", "cc" \
); \
_arg1; \
})
#define my_syscall5(num, arg1, arg2, arg3, arg4, arg5) \
({ \
register long _num __asm__ ("1") = (num); \
register long _arg1 __asm__ ("2") = (long)(arg1); \
register long _arg2 __asm__ ("3") = (long)(arg2); \
register long _arg3 __asm__ ("4") = (long)(arg3); \
register long _arg4 __asm__ ("5") = (long)(arg4); \
register long _arg5 __asm__ ("6") = (long)(arg5); \
\
__asm__ volatile ( \
"svc 0\n" \
: "+d"(_arg1) \
: "d"(_arg2), "d"(_arg3), "d"(_arg4), "d"(_arg5), \
"d"(_num) \
: "memory", "cc" \
); \
_arg1; \
})
#define my_syscall6(num, arg1, arg2, arg3, arg4, arg5, arg6) \
({ \
register long _num __asm__ ("1") = (num); \
register long _arg1 __asm__ ("2") = (long)(arg1); \
register long _arg2 __asm__ ("3") = (long)(arg2); \
register long _arg3 __asm__ ("4") = (long)(arg3); \
register long _arg4 __asm__ ("5") = (long)(arg4); \
register long _arg5 __asm__ ("6") = (long)(arg5); \
register long _arg6 __asm__ ("7") = (long)(arg6); \
\
__asm__ volatile ( \
"svc 0\n" \
: "+d"(_arg1) \
: "d"(_arg2), "d"(_arg3), "d"(_arg4), "d"(_arg5), \
"d"(_arg6), "d"(_num) \
: "memory", "cc" \
); \
_arg1; \
})
/* startup code */
void __attribute__((weak, noreturn)) __nolibc_entrypoint __no_stack_protector _start(void)
{
__asm__ volatile (
"lgr %r2, %r15\n" /* save stack pointer to %r2, as arg1 of _start_c */
"aghi %r15, -160\n" /* allocate new stackframe */
"xc 0(8,%r15), 0(%r15)\n" /* clear backchain */
"brasl %r14, _start_c\n" /* transfer to c runtime */
);
__nolibc_entrypoint_epilogue();
}
struct s390_mmap_arg_struct {
unsigned long addr;
unsigned long len;
unsigned long prot;
unsigned long flags;
unsigned long fd;
unsigned long offset;
};
static __attribute__((unused))
void *sys_mmap(void *addr, size_t length, int prot, int flags, int fd,
off_t offset)
{
struct s390_mmap_arg_struct args = {
.addr = (unsigned long)addr,
.len = (unsigned long)length,
.prot = prot,
.flags = flags,
.fd = fd,
.offset = (unsigned long)offset
};
return (void *)my_syscall1(__NR_mmap, &args);
}
#define sys_mmap sys_mmap
static __attribute__((unused))
pid_t sys_fork(void)
{
return my_syscall5(__NR_clone, 0, SIGCHLD, 0, 0, 0);
}
#define sys_fork sys_fork
#endif /* _NOLIBC_ARCH_S390_H */