#include <u.h>
#include <libc.h>
#include <tos.h>

/*
/n/unix/usr/include/asm-generic/errno-base.h
/n/unix/usr/include/asm-generic/errno.h
/sys/src/9/port/error.h
*/
static char *errtab[] = {
	[1]	"operation not permitted",
	[2]	"file does not exist",
	[3]	"no such process",
	[4]	"interrupted",
	[5]	"i/o error",
	[6]	"no such device or address",
	[7]	"argument list too long",
	[8]	"exec format error",
	[9]	"fd out of range or not open",
	[10]	"no child process",
	[11]	"try again",
	[12]	"out of memory",
	[13]	"permission denied",
	[14]	"bad address",
	[15]	"block device required",
	[16]	"busy",
	[17]	"file already exists",
	[18]	"cross-device link",
	[19]	"no such device",
	[20]	"not a directory",
	[21]	"file is a directory",
	[22]	"bad arg in system call",
	[23]	"no free file descriptors",
	[24]	"too many open files",
	[25]	"not a typewriter",
	[26]	"text file busy",
	[27]	"file too large",
	[28]	"no space left on device",
	[29]	"seek on a stream",
	[30]	"read-only file system",
	[31]	"too many links",
	[32]	"broken pipe",
	[33]	"argument out of domain",
	[34]	"result out or range",

	[35]	"would deadlock",
	[36]	"name too long",
	[37]	"no record locks available",
	[38]	"not implemented",
	[39]	"directory not empty",
	[40]	"symlink loop",
	[41]	"would block",
	[42]	"no message of desired type",
	[43]	"identifier removed",
	[44]	"channel number out of range",
	[45]	"level 2 not synchronized",
	[46]	"level 3 halted",
	[47]	"level 3 reset",
	[48]	"link number out of range",
	[49]	"protocol driver not attached",

	[88]	"not a socket",
	[89]	"destination address required",
	[90]	"message too long",
	[91]	"wrong protocol type",
	[92]	"protocol not avalable",
	[93]	"protocol not supported",
	[94]	"socket type not supported",
	[95]	"operation not supported on endpoint",
	[96]	"protocol family not supported",
	[97]	"address family not supported",
	[98]	"address already in use",
	[99]	"cannot assign requested address",
	[100]	"network is down",
	[101]	"network is unreachable",
	[102]	"connection reset",
	[103]	"connection aborted",
	[104]	"connection reset by peer",
	[105]	"no buffer space available",
	[106]	"endpoint is already connected",
	[107]	"endpoint is not connected",
	[108]	"endpoint is shut down",
	[109]	"too many references",
	[110]	"connection timed out",
	[111]	"connection refused",
	[112]	"host is down",
	[113]	"no route to host",
};

extern long _syscall6(long, long, long, long, long, long, long);

int
_mktos(void)
{
	_tos->cyclefreq = 0;
	_tos->kcycles = -1;
	_tos->pcycles = -1;
	_tos->pid = getpid();
	_tos->clock = 0;
	return sizeof(Tos);
}

static long
syscall6(long sys, long a1, long a2, long a3, long a4, long a5, long a6)
{
	long r;

	if((r = _syscall6(sys, a1, a2, a3, a4, a5, a6)) < 0) {
		r = -r;
		if(r < nelem(errtab) && errtab[r] != nil)
			werrstr("%s", errtab[r]);
		else
			werrstr("errno %ld", r);
		return -1;
	}
	return r;
}

void
_exits(char *msg)
{
	ulong code;

	for(code = 0; msg != nil && *msg != '\0'; msg++)
		code = 33*code + *msg;
	syscall6(1, code, 0, 0, 0, 0, 0);
}

long
read(int fd, void *buf, long n)
{
	return syscall6(3, fd, (long)buf, n, 0, 0, 0);
}

long
write(int fd, void *buf, long n)
{
	return syscall6(4, fd, (long)buf, n, 0, 0, 0);
}

int
open(char *name, int mode)
{
	return syscall6(5, (long)name, mode, 0, 0, 0, 0);
}

int
close(int fd)
{
	return syscall6(6, fd, 0, 0, 0, 0, 0);
}

int
brk_(void *addr)
{
	if((void *)syscall6(45, (long)addr, 0, 0, 0, 0, 0) < addr)
		return 0;
	werrstr("no memory");
	return -1;
}

long
pread(int fd, void *buf, long n, vlong o)
{
	if(o == -1LL)
		return read(fd, buf, n);
	return syscall6(180, fd, (long)buf, n, o, o>>32, 0);
}

long
pwrite(int fd, void *buf, long n, vlong o)
{
	if(o == -1LL)
		return write(fd, buf, n);
	return syscall6(181, fd, (long)buf, n, o, o>>32, 0);
}

/* /sys/src/9/port/sysproc.c:/^generrstr */
int
errstr(char *buf, uint nbuf)
{
	static char upsyserrstr[ERRMAX];
	char tmp[ERRMAX];

	if(nbuf == 0) {
		werrstr("bad arg in system call");
		return -1;
	}
	if(nbuf > ERRMAX)
		nbuf = ERRMAX;
	memmove(tmp, buf, nbuf);

	/* make sure it's NUL-terminated */
	tmp[nbuf-1] = '\0';
	memmove(buf, upsyserrstr, nbuf);
	buf[nbuf-1] = '\0';
	memmove(upsyserrstr, tmp, nbuf);
	return 0;
}

int
getpid(void)
{
	return syscall6(20, 0, 0, 0, 0, 0, 0);
}

int
brk(void *)
{
	sysfatal("brk");
	return -1;
}

void *
sbrk(ulong n)
{
	uintptr b0, b;

	b0 = syscall6(45, 0, 0, 0, 0, 0, 0);
	if((b = syscall6(45, b0 + n, 0, 0, 0, 0, 0)) != b0 + n)
		return nil;
fprint(2, "brk'ing %uldB %#ulx\n", n, n);
fprint(2, "new brk is %#p; old was %#p\n", (void *)b, (void *)b0);
	return (void *)b;
}