plat/msdos86: add isatty( ), _setmode( ), read( ), write( )

plat/msdos86/descr

@@ -73,6 +73,8 @@ name led
 		{FLOATS?} \
 		(.e:{TAIL}={PLATFORMDIR}/libem.a \
 		           {PLATFORMDIR}/libsys.a \
+		           {PLATFORMDIR}/libc.a \
+		           {PLATFORMDIR}/libem.a \
 		           {PLATFORMDIR}/libend.a)
 	linker
 end

plat/msdos86/include/ack/plat.h

@@ -0,0 +1,12 @@
+/* $Source$
+ * $State$
+ * $Revision$
+ */
+
+#ifndef _ACK_PLAT_H
+#define _ACK_PLAT_H
+
+#define ACKCONF_WANT_O_TEXT_O_BINARY 1
+#define ACKCONF_WANT_EMULATED_TIME 0
+
+#endif

plat/msdos86/include/build.lua

@@ -0,0 +1,24 @@
+include("plat/build.lua")
+
+headermap = {}
+packagemap = {}
+
+local function addheader(h)
+	headermap[h] = "./"..h
+	packagemap["$(PLATIND)/msdos86/include/"..h] = "./"..h
+end
+
+addheader("ack/plat.h")
+addheader("sys/types.h")
+
+acklibrary {
+	name = "headers",
+	hdrs = headermap
+}
+
+installable {
+	name = "pkg",
+	map = packagemap
+}
+
+

plat/msdos86/include/sys/types.h

@@ -0,0 +1,9 @@
+#ifndef _SYS_TYPES_H
+#define _SYS_TYPES_H
+
+typedef int pid_t;
+typedef int mode_t;
+typedef long time_t;
+typedef long suseconds_t;
+
+#endif

plat/msdos86/libsys/_hol0.s

@@ -0,0 +1,19 @@
+#
+! $Source$
+! $State$
+! $Revision$
+
+! Declare segments (the order is important).
+
+.sect .text
+.sect .rom
+.sect .data
+.sect .bss
+
+.sect .bss
+
+! This data block is used to store information about the current line number
+! and file.
+
+.define hol0
+.comm hol0, 8

plat/msdos86/libsys/brk.c

@@ -0,0 +1,59 @@
+/* $Source$
+ * $State$
+ * $Revision$
+ */
+
+#include <stdlib.h>
+#include <errno.h>
+#include <unistd.h>
+#include "libsys.h"
+
+#define STACK_BUFFER 128 /* number of bytes to leave for stack */
+
+extern char _end[1];
+static char* current = _end;
+
+int brk(void* newend)
+{
+	/* This variable is used to figure out the current stack pointer,
+	 * by taking its address. */
+	char dummy;
+	char* p = newend;
+	
+	if ((p > (&dummy - STACK_BUFFER)) ||
+	    (p < _end))	
+	{
+		errno = ENOMEM;
+		return -1;
+	}
+		
+	current = p;
+	return 0;
+}
+
+void* sbrk(int increment)
+{
+	char* old;
+	char* new;
+
+	if (increment == 0)
+		return current;
+		
+	old = current;
+
+	new = old + increment;
+
+	if ((increment > 0) && (new <= old))
+		goto out_of_memory;
+	else if ((increment < 0) && (new >= old))
+		goto out_of_memory;
+
+	if (brk(new) < 0)
+		goto out_of_memory;
+		
+	return old;
+
+out_of_memory:
+	errno = ENOMEM;
+	return OUT_OF_MEMORY;
+}

plat/msdos86/libsys/build.lua

@@ -0,0 +1,15 @@
+acklibrary {
+    name = "lib",
+    srcs = {
+        "./*.c",
+        "./*.s",
+    },
+	deps = {
+		"lang/cem/libcc.ansi/headers+headers",
+		"plat/msdos86/include+headers",
+	},
+    vars = {
+        plat = "msdos86"
+    }
+}
+

plat/msdos86/libsys/creat.c

@@ -0,0 +1,14 @@
+/* $Source$
+ * $State$
+ * $Revision$
+ */
+
+#include <stdlib.h>
+#include <errno.h>
+#include <unistd.h>
+#include "libsys.h"
+
+int creat(const char* path, int mode)
+{
+	return open(path, O_CREAT|O_WRONLY|O_TRUNC, mode);
+}

plat/msdos86/libsys/isatty.s

@@ -0,0 +1,37 @@
+#
+! $Source$
+! $State$
+! $Revision$
+
+! Declare segments (the order is important).
+
+.sect .text
+.sect .rom
+.sect .data
+.sect .bss
+
+.sect .text
+
+! Say whether a given file descriptor number refers to a terminal.
+
+.define _isatty
+_isatty:
+	mov bx, sp
+	mov bx, 2(bx)
+	mov ax, 0x4400
+	int 0x21
+	jc error
+	testb dl, dl
+	jz not_tty
+	mov ax, 1
+	ret
+not_tty:
+	mov (_errno), 25		! ENOTTY
+not_tty_2:
+	xor ax, ax
+	ret
+error:
+	push ax
+	call __sys_seterrno
+	pop cx
+	jmp not_tty_2

plat/msdos86/libsys/libsys.h

@@ -0,0 +1,53 @@
+/* $Source$
+ * $State$
+ * $Revision$
+ */
+
+#ifndef LIBSYS_H
+#define LIBSYS_H
+
+#include <limits.h>
+#include <stdint.h>
+#include <sys/types.h>
+
+#define OUT_OF_MEMORY ((void *)-1)	/* sbrk returns this on failure */
+
+/*
+ * Data structure for remembering whether each file descriptor is open in
+ * text mode (O_TEXT) or binary mode (O_BINARY).
+ *
+ * Currently this is just a simple linked list, where each linked list node
+ * records the modes for 16 file descriptors, in bit vector form (0: text,
+ * 1: binary).  In addition, each node also remembers, for each of its file
+ * descriptors,  whether an end-of-file (^Z) character was encountered when
+ * reading from it in text mode.
+ *
+ * List nodes are allocated using sbrk() and never freed.
+ *
+ * This scheme should be fast and light enough, as the number of open file
+ * descriptors is expected to be small.
+ *
+ * FIXME: the code for updating this structure is not exactly thread-safe.
+ */
+typedef uint16_t _fdvec_t;
+
+struct _fdmodes {
+	struct _fdmodes *next;
+	int begfd;
+	_fdvec_t modevec, eofvec;
+};
+
+extern struct _fdmodes _sys_fdmodes;
+
+#define _FDVECMASK (sizeof(_fdvec_t) * CHAR_BIT - 1)
+
+extern int _sys_getmode(int);
+extern int _sys_setmode(int, int);
+extern int _sys_iseof(int);
+extern int _sys_seteof(int, int);
+extern ssize_t _sys_rawread(int, char *, size_t);
+extern ssize_t _sys_rawwrite(int, const char *, size_t);
+extern int _sys_isopen(int);
+extern int _sys_isreadyr(int);
+
+#endif

plat/msdos86/libsys/read.c

@@ -0,0 +1,77 @@
+/* $Source$
+ * $State$
+ * $Revision$
+ */
+
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+#include <errno.h>
+#include <unistd.h>
+#include "libsys.h"
+
+ssize_t read(int fd, void* buffer, size_t count)
+{
+	char *p, *q;
+	ssize_t r, tot;
+	size_t left;
+	int eof = 0;
+
+	if (!count || _sys_getmode(fd) == O_BINARY)
+		return _sys_rawread(fd, buffer, count);
+
+	if (_sys_iseof(fd))
+		return 0;
+
+	/*
+	 * If the file descriptor is an O_TEXT fd, read from it, and then
+	 * remove CRs from the input.  After removing CRs, if the buffer is
+	 * not filled and the fd still has bytes left to read, then keep
+	 * reading, and keep removing CRs.
+	 *
+	 * Also handle end-of-file indicators (^Z).  If we see one, move the
+	 * file pointer to just before the ^Z.  Also set an internal flag
+	 * for the fd so that we do not try to read any further (until e.g. 
+	 * a seek happens).
+	 */
+	p = buffer;
+	tot = 0;
+
+	do
+	{
+		r = _sys_rawread(fd, p, count - (p - (char *)buffer));
+		if (r <= 0)
+			return tot;
+
+		q = memchr(p, 0x1a, (size_t)r);
+		if (q)
+		{
+			_sys_rawlseek(fd, (off_t)(q - p) - r, SEEK_CUR);
+			r = q - p;
+			eof = 1;
+			_sys_seteof(fd, 1);
+		}
+
+		q = memchr(p, '\r', (size_t)r);
+		if (!q)
+			return tot + r;
+
+		tot += q - p;
+		left = r - (q + 1 - p);
+		p = q;
+		++q;
+
+		while (left)
+		{
+			char c = *q++;
+			if (c != '\r')
+			{
+				*p++ = c;
+				++tot;
+			}
+			--left;
+		}
+	} while (tot < count && !eof && _sys_isreadyr(fd));
+
+	return tot;
+}

plat/msdos86/libsys/setmode.c

@@ -0,0 +1,23 @@
+/* $Source$
+ * $State$
+ * $Revision$
+ */
+
+#include <errno.h>
+#include <fcntl.h>
+#include "libsys.h"
+
+int _setmode(int fd, int mode)
+{
+	if (mode != O_TEXT && mode != O_BINARY)
+	{
+		errno = EINVAL;
+		return -1;
+	}
+	if (!_sys_isopen(fd))
+	{
+		errno = EBADF;
+		return -1;
+	}
+	return _sys_setmode(fd, mode);
+}

plat/msdos86/libsys/sys_fdmodes.c

@@ -0,0 +1,13 @@
+/* $Source$
+ * $State$
+ * $Revision$
+ */
+
+#include <stdlib.h>
+#include "libsys.h"
+
+/*
+ * By default, consider all file descriptors, including those for stdin (0),
+ * stdout (1), and stderr (2), as being open in text mode.
+ */
+struct _fdmodes _sys_fdmodes = { NULL, 0, 0 };

plat/msdos86/libsys/sys_getmode.c

@@ -0,0 +1,27 @@
+/* $Source$
+ * $State$
+ * $Revision$
+ */
+
+#include <fcntl.h>
+#include "libsys.h"
+
+/*
+ * Say whether a particular fd is currently open in text or binary mode.
+ * Assume that the fd is valid.  Return O_TEXT or O_BINARY.
+ */
+int _sys_getmode(int fd)
+{
+	int reqbegfd = fd & ~_FDVECMASK;
+	struct _fdmodes *p = &_sys_fdmodes;
+	_fdvec_t mask;
+
+	while (p->begfd != reqbegfd)
+	{
+		p = p->next;
+		if (!p)
+			return O_TEXT;
+	}
+	mask = (_fdvec_t)1 << (fd & _FDVECMASK);
+	return (p->modevec & mask) ? O_BINARY : O_TEXT;
+}

plat/msdos86/libsys/sys_initmain.c

@@ -6,8 +6,7 @@
 #include <stdlib.h>
 #include <string.h>
 #include <unistd.h>
-
-#define	OUT_OF_MEMORY (void*)(-1)	/* sbrk returns this on failure */
+#include "libsys.h"
 
 struct for_main {
 	int argc;

plat/msdos86/libsys/sys_iseof.c

@@ -0,0 +1,27 @@
+/* $Source$
+ * $State$
+ * $Revision$
+ */
+
+#include <fcntl.h>
+#include "libsys.h"
+
+/*
+ * Say whether a particular fd is currently open in text mode and has just
+ * hit an MS-DOS end-of-file character (^Z).
+ */
+int _sys_iseof(int fd)
+{
+	int reqbegfd = fd & ~_FDVECMASK;
+	struct _fdmodes *p = &_sys_fdmodes;
+	_fdvec_t mask;
+
+	while (p->begfd != reqbegfd)
+	{
+		p = p->next;
+		if (!p)
+			return 0;
+	}
+	mask = (_fdvec_t)1 << (fd & _FDVECMASK);
+	return p->eofvec & mask;
+}

plat/msdos86/libsys/sys_isopen.s

@@ -0,0 +1,26 @@
+#
+! $Source$
+! $State$
+! $Revision$
+
+! Declare segments (the order is important).
+
+.sect .text
+.sect .rom
+.sect .data
+.sect .bss
+
+.sect .text
+
+! Say whether a given file descriptor number refers to a valid open file
+! descriptor.
+
+.define __sys_isopen
+__sys_isopen:
+	mov bx, sp
+	mov bx, 2(bx)
+	mov ax, 0x4400
+	int 0x21
+	sbb ax, ax
+	inc ax
+	ret

plat/msdos86/libsys/sys_isreadyr.s

@@ -0,0 +1,28 @@
+#
+! $Source$
+! $State$
+! $Revision$
+
+! Declare segments (the order is important).
+
+.sect .text
+.sect .rom
+.sect .data
+.sect .bss
+
+.sect .text
+
+! Say whether a file descriptor is ready for input, i.e. reading from the
+! fd will immediately return something.
+
+.define __sys_isreadyr
+__sys_isreadyr:
+	mov bx, sp
+	mov ax, 0x4406
+	mov bx, 2(bx)
+	int 0x21
+	jnc ok
+	movb al, 0
+ok:
+	cbw
+	ret

plat/msdos86/libsys/sys_rawrw.s

@@ -0,0 +1,33 @@
+#
+! $Source$
+! $State$
+! $Revision$
+
+! Declare segments (the order is important).
+
+.sect .text
+.sect .rom
+.sect .data
+.sect .bss
+
+.sect .text
+
+! Read/write bytes to/to a file descriptor.  These routines do not do any
+! translation between CRLF and LF line endings.
+!
+! Note that, for MS-DOS, a raw "write" request of zero bytes will truncate
+! (or extend) the file to the current file position.
+
+.define __sys_rawread
+__sys_rawread:
+	movb ah, 0x3f
+	.data1 0x3d			! eat up the next instruction
+.define __sys_rawwrite
+__sys_rawwrite:
+	movb ah, 0x40
+	mov bx, sp
+	mov dx, 4(bx)
+	mov cx, 6(bx)
+	mov bx, 2(bx)
+	int 0x21
+	jmp .sys_axret

plat/msdos86/libsys/sys_seteof.c

@@ -0,0 +1,42 @@
+/* $Source$
+ * $State$
+ * $Revision$
+ */
+
+#include <fcntl.h>
+#include "libsys.h"
+
+/*
+ * Set or reset the "end-of-file encountered" indicator for a particular fd.
+ * Assume that the fd is valid, and is being read from in text mode.
+ */
+int _sys_seteof(int fd, int eof)
+{
+	int reqbegfd = fd & ~_FDVECMASK;
+	struct _fdmodes *p = &_sys_fdmodes;
+	_fdvec_t mask;
+
+	while (p->begfd != reqbegfd)
+	{
+		p = p->next;
+		if (!p)
+		{
+			if (!eof)
+				return 0;
+			if ((p = sbrk(sizeof(struct _fdmodes)))
+			    == OUT_OF_MEMORY)
+				return -1;
+			p->next = _sys_fdmodes.next;
+			p->begfd = reqbegfd;
+			p->modevec = p->eofvec = 0;
+			_sys_fdmodes.next = p;
+			break;
+		}
+	}
+	mask = (_fdvec_t)1 << (fd & _FDVECMASK);
+	if (eof)
+		p->eofvec |= mask;
+	else
+		p->eofvec &= ~mask;
+	return 0;
+}

plat/msdos86/libsys/sys_setmode.c

@@ -0,0 +1,55 @@
+/* $Source$
+ * $State$
+ * $Revision$
+ */
+
+#include <fcntl.h>
+#include "libsys.h"
+
+/*
+ * Set text/binary mode for a particular fd.  Assume that the fd is valid,
+ * and that the mode is either O_TEXT or O_BINARY.
+ *
+ * Return the previous mode (either O_TEXT or O_BINARY) on success, -1 (with
+ * errno set) on error.
+ */
+int _sys_setmode(int fd, int mode)
+{
+	int reqbegfd = fd & ~_FDVECMASK;
+	struct _fdmodes *p = &_sys_fdmodes;
+	_fdvec_t mask;
+
+	while (p->begfd != reqbegfd)
+	{
+		p = p->next;
+		if (!p)
+		{
+			if (mode == O_TEXT)
+				return O_TEXT;
+			if ((p = sbrk(sizeof(struct _fdmodes)))
+			    == OUT_OF_MEMORY)
+				return -1;
+			p->next = _sys_fdmodes.next;
+			p->begfd = reqbegfd;
+			p->modevec = p->eofvec = 0;
+			_sys_fdmodes.next = p;
+			break;
+		}
+	}
+	mask = (_fdvec_t)1 << (fd & _FDVECMASK);
+	if (mode == O_BINARY)
+	{
+		if (p->modevec & mask)
+			return O_BINARY;
+		p->modevec |= mask;
+		p->eofvec &= ~mask;
+		return O_TEXT;
+	}
+	else
+	{
+		if (!(p->modevec & mask))
+			return O_TEXT;
+		p->modevec &= ~mask;
+		return O_BINARY;
+	}
+}

plat/msdos86/libsys/write.c

@@ -0,0 +1,61 @@
+/* $Source$
+ * $State$
+ * $Revision$
+ */
+
+#include <stdlib.h>
+#include <string.h>
+#include <errno.h>
+#include <unistd.h>
+#include "libsys.h"
+
+ssize_t write(int fd, void* buffer, size_t count)
+{
+	static const char crlf[2] = "\r\n";
+	int i;
+	char *p, *q;
+	size_t left, n;
+	ssize_t r, tot;
+
+	if (!count)
+		return 0;
+
+	if (_sys_getmode(fd) == O_BINARY)
+		return _sys_rawwrite(fd, buffer, count);
+
+	/* If the file descriptor is an O_TEXT fd, translate LFs to CRLFs. */
+	p = buffer;
+	left = count;
+	tot = 0;
+	while (left)
+	{
+		q = memchr(p, '\n', left);
+		if (!q)
+			return _sys_rawwrite(fd, p, left);
+
+		n = q - p;
+		if (n)
+		{
+			r = _sys_rawwrite(fd, p, n);
+			if (r <= 0)
+				return tot ? tot : r;
+			tot += r;
+			p += r;
+			left -= r;
+			if (r != n)
+				break;
+		}
+
+		r = _sys_rawwrite(fd, crlf, sizeof crlf);
+		if (r != 2)
+		{
+			if (r > 0)
+				r = 0;
+			return tot ? tot : r;
+		}
+		++tot;
+		++p;
+		--left;
+	}
+	return tot;
+}