Add unicode and NLS support

5 files changed, 449 insertions, 28 deletions

diff --git a/int21dos.h b/int21dos.h
index af22fea..790bd88 100644
--- a/int21dos.h
+++ b/int21dos.h
@@ -293,6 +293,24 @@ typedef _Packed struct dos_list_of_lists {
 	uint8_t last_drive;
 } DOSLOL;
 
+typedef _Packed struct dos_nls_table {
+	uint8_t table_id;
+	void __far *table_data;
+} NLSTABLE;
+
+typedef _Packed struct file_char_table {
+	uint16_t	size;		// table size (not counting this word)
+	uint8_t		unk1;		// ??? (01h for MS-DOS 3.30-6.00)
+	uint8_t		lowest;		// lowest permissible character value for filename
+	uint8_t		highest;	// highest permissible character value for filename
+	uint8_t		unk2;		// ??? (00h for MS-DOS 3.30-6.00)
+	uint8_t		first_x;	// first excluded character in range \ all characters in this
+	uint8_t		last_x;		// last excluded character in range  / range are illegal
+	uint8_t		unk3;		// ??? (02h for MS-DOS 3.30-6.00)
+	uint8_t		n_illegal;	// number of illegal (terminator) characters
+	uint8_t		illegal[1];	// characters which terminate a filename:       ."/\[]:|<>+=;,
+} FCHAR;
+
 static inline int drive_letter_to_index(char letter)
 {
 	if (letter >= 'A' && letter <= 'Z') return letter - 'A';
diff --git a/sfmain.c b/sfmain.c
index c0f292f..04b4d1b 100644
--- a/sfmain.c
+++ b/sfmain.c
@@ -17,17 +17,20 @@
  * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301, USA.
  */
 
+#define __STDC_WANT_LIB_EXT1__ 1
 #include <stdio.h>
 #include <stdlib.h>
 #include <string.h>
 #include <time.h>
 #include <dos.h>
+#include <sys/stat.h>
 
 #include "version.h"
 #include "dlog.h"
 #include "vboxshfl.h"
 #include "dostsr.h"
 #include "sftsr.h"
+#include "unicode.h"
 
 static char get_drive_letter(const char *path) {
 	if (!path || path[0] == '\0') return '\0';
@@ -77,6 +80,7 @@ static int list_folders(LPTSRDATA data)
 			continue;
 		}
 
+		(void)utf8_to_local(data, str.buf, str.buf, NULL);
 		printf(" %s on %c:\n", str.buf, drive_index_to_letter(i));
 	}
 
@@ -95,6 +99,7 @@ static int list_folders(LPTSRDATA data)
 			continue;
 		}
 
+		(void)utf8_to_local(data, str.buf, str.buf, NULL);
 		printf(" %s\n", str.buf);
 	}
 
@@ -172,7 +177,7 @@ static int unmount_shfl(LPTSRDATA data, int drive)
 	return 0;
 }
 
-static int mount(LPTSRDATA data, const char *folder, char drive_letter)
+static int mount(LPTSRDATA data, char *folder, char drive_letter)
 {
 	int drive = drive_letter_to_index(drive_letter);
 	DOSLOL __far *lol = dos_get_list_of_lists();
@@ -209,6 +214,7 @@ static int mount(LPTSRDATA data, const char *folder, char drive_letter)
 	// By setting the physical flag, we also let DOS know the drive is present
 	cds->flags = DOS_CDS_FLAG_NETWORK | DOS_CDS_FLAG_PHYSICAL;
 
+	(void)utf8_to_local(data, folder, folder, NULL);
 	printf("Shared folder '%s' mounted as drive %c:\n", folder, drive_letter);
 
 	return EXIT_SUCCESS;
@@ -335,6 +341,117 @@ static int rescan(LPTSRDATA data)
 	return 0;
 }
 
+static int get_nls(uint8_t __far * __far *file_upper_case, FCHAR __far * __far *file_char)
+{
+	union REGS r;
+	struct SREGS s;
+	static NLSTABLE nls_table;
+
+	segread(&s);
+
+	// Get FUCASE (File Uppercase Table)
+	//
+	r.w.ax = 0x6504;
+	r.x.bx  = r.x.dx = 0xffff;
+	r.x.cx  = 5;
+
+	s.es    = s.ds;
+	r.x.di  = (uint16_t) &nls_table;
+
+	intdosx(&r, &r, &s);
+
+	if (r.x.cx != 5)
+		return 1;
+
+	*file_upper_case = (uint8_t __far *)nls_table.table_data + 2;   // Skip size word
+
+	// Get FCHAR (File Terminator Table)
+	//
+	r.w.ax  = 0x6505;
+
+	intdosx(&r, &r, &s);
+
+	if ( r.x.cx != 5 )
+		return 1;
+
+	*file_char = (FCHAR __far *)nls_table.table_data;
+
+	return 0;
+}
+
+static void load_unicode_table(uint16_t far *unicode_table)
+{
+	union REGS r;
+	char filename[13];
+	char fullpath[_MAX_PATH];
+	char buffer[256];
+	struct stat filestat;
+	FILE *f;
+	int i, ret;
+
+	// get current Code Page
+	//
+	//      AX = 6601h
+	//        Return: CF set on error
+	//          AX = error code (see #01680 at AH=59h/BX=0000h)
+	//        CF clear if successful
+	//      BX = active code page (see #01757) <---
+	//      DX = system code page (see #01757)
+	//
+	r.w.ax = 0x6601;
+
+	intdos(&r, &r);
+
+	if (r.x.cflag) {
+		// Can't get codepage. Use ASCII only
+		//
+		fputs("Warning: Active code page not found", stderr);
+		goto error;
+	}
+
+	sprintf(filename, r.x.bx > 999 ? "c%duni.tbl" : "cp%duni.tbl", r.x.bx);
+
+	_searchenv(filename, "PATH", fullpath);
+	if ( '\0' == fullpath[0] ) {
+		fprintf(stderr, "Warning: Can't find Unicode table: %s", filename);
+		goto error;
+	}
+
+	f = fopen(fullpath, "rb");
+
+	if ( NULL == f ) {
+		fprintf(stderr, "Warning: Can't load Unicode table: %s", filename);
+		goto error;
+	}
+
+	if ( EOF == fscanf_s(f, "Unicode (%s)", buffer, sizeof(buffer)) ) {
+		fprintf(stderr, "Warning: Invalid file format: %s", filename);
+		goto close;
+	}
+
+	ret = fread(buffer, 1, 3, f);
+
+	if ( ret != 3 || buffer[0] != '\r' || buffer[1] != '\n' || buffer[2] != 1 ) {
+		fprintf(stderr, "Warning: Invalid file format: %s", filename);
+		goto close;
+	}
+
+	if ( 256 != (ret = fread( buffer, 1, 256, f )) ) {
+		fprintf(stderr, "Warning: Can't load Unicode table: %s", filename);
+		goto close;
+	}
+
+	_fmemcpy(unicode_table, (char far *)buffer, 256);
+
+	return;
+
+close:
+	fclose(f);
+error:
+	fputs( ". Defaulting to cp437\n", stderr );
+
+}
+
 static int configure_driver(LPTSRDATA data)
 {
 	unsigned i;
@@ -395,6 +512,14 @@ static int configure_driver(LPTSRDATA data)
 		return -1;
 	}
 
+	err = get_nls(&data->file_upper_case, &data->file_char);
+	if (err) {
+		puts("Cannot get the NLS tables.");
+		return -1;
+	}
+
+	load_unicode_table( &data->unicode_table);
+	
 	printf("Connected to VirtualBox shared folder service\n");
 
 	return 0;
@@ -594,13 +719,13 @@ int main(int argc, const char *argv[])
 		if (!data) return driver_not_found();
 		return list_folders(data);
 	} else if (stricmp(argv[argi], "mount") == 0) {
-		const char *folder;
+		char *folder;
 		char drive;
 		if (!data) return driver_not_found();
 
 		argi++;
 		if (argi >= argc) return arg_required("mount");
-		folder = argv[argi];
+		folder = (char *) argv[argi];
 		argi++;
 		if (argi >= argc) return arg_required("mount");
 		drive = get_drive_letter(argv[argi]);
diff --git a/sftsr.c b/sftsr.c
index b48a42d..5819ce5 100644
--- a/sftsr.c
+++ b/sftsr.c
@@ -25,8 +25,36 @@
 #include "unixtime.h"
 #include "vboxshfl.h"
 #include "sftsr.h"
-
-TSRDATA data;
+#define __IN_SFTSR__ 1
+#include "unicode.h"
+
+TSRDATA data = {
+	// TSR installation data
+	NULL, /** Previous int2f ISR, storing it for uninstall. */
+	NULL, /** Stored pointer for the DOS SDA. */
+
+	// TSR configuration
+	0,          /** Offset (in seconds/2) of the current timezone. */
+	NULL, NULL, /** NLS support tables. */
+	{           /** Codepage to unicode lookup table.
+	             *  Initialised to cp437 */
+		0x00C7, 0x00FC, 0x00E9, 0x00E2, 0x00E4, 0x00E0, 0x00E5, 0x00E7,
+		0x00EA, 0x00EB, 0x00E8, 0x00EF, 0x00EE, 0x00EC, 0x00C4, 0x00C5,
+		0x00C9, 0x00E6, 0x00C6, 0x00F4, 0x00F6, 0x00F2, 0x00FB, 0x00F9,
+		0x00FF, 0x00D6, 0x00DC, 0x00A2, 0x00A3, 0x00A5, 0x20A7, 0x0192,
+		0x00E1, 0x00ED, 0x00F3, 0x00FA, 0x00F1, 0x00D1, 0x00AA, 0x00BA,
+		0x00BF, 0x2310, 0x00AC, 0x00BD, 0x00BC, 0x00A1, 0x00AB, 0x00BB,
+		0x2591, 0x2592, 0x2593, 0x2502, 0x2524, 0x2561, 0x2562, 0x2556,
+		0x2555, 0x2563, 0x2551, 0x2557, 0x255D, 0x255C, 0x255B, 0x2510,
+		0x2514, 0x2534, 0x252C, 0x251C, 0x2500, 0x253C, 0x255E, 0x255F,
+		0x255A, 0x2554, 0x2569, 0x2566, 0x2560, 0x2550, 0x256C, 0x2567,
+		0x2568, 0x2564, 0x2565, 0x2559, 0x2558, 0x2552, 0x2553, 0x256B,
+		0x256A, 0x2518, 0x250C, 0x2588, 0x2584, 0x258C, 0x2590, 0x2580,
+		0x03B1, 0x00DF, 0x0393, 0x03C0, 0x03A3, 0x03C3, 0x03BC, 0x03C4,
+		0x03A6, 0x0398, 0x03A9, 0x03B4, 0x221E, 0x03C6, 0x03B5, 0x2229,
+		0x2261, 0x00B1, 0x2265, 0x2264, 0x2320, 0x2321, 0x00F7, 0x2248,
+		0x00B0, 0x2219, 0x00B7, 0x221A, 0x207F, 0x00B2, 0x25A0, 0x00A0 }
+};
 
 /** Private buffer for VirtualBox filenames. */
 static SHFLSTRING_WITH_BUF(shflstr, SHFL_MAX_LEN);
@@ -213,22 +241,59 @@ static const char * get_basename(const char *path)
 	}
 }
 
-static void translate_filename_to_host(SHFLSTRING *str)
+static bool illegal_char( unsigned char c )
+{
+	int i= 0;
+	
+	for ( i= 0; i < data.file_char->n_illegal; ++i )
+	{
+		if ( c == data.file_char->illegal[i] )
+		{
+			return true;
+		}
+	}
+	if (  ( c < data.file_char->lowest || c > data.file_char->highest ) ||
+	     !( c < data.file_char->first_x || c > data.file_char->last_x ) )
+	{
+		return true;
+	}
+	
+	return false;
+}
+
+static unsigned char nls_toupper( unsigned char c )
 {
-	// TODO This should map UTF-8 to local CP :(
-	(void) str;
+	if ( c > 0x60 && c < 0x7b )
+	{
+		return c & 0xDF;
+	}
+	
+	return ( c < 0x80 ? c : data.file_upper_case[c - 0x80] );
 }
 
-static void translate_filename_from_host(SHFLSTRING *str)
+static inline bool translate_filename_from_host(SHFLSTRING *str)
 {
-	// TODO This should map UTF-8 to local CP :(
-	// At least do a poor man's uppercase...
 	unsigned i;
+	bool ret;
+	unsigned dots = 0;
+
+	ret = utf8_to_local(&data, str->ach, str->ach, &str->u16Length);
+
 	for (i = 0; i < str->u16Length; i++) {
-		if (str->ach[i] >= 'a' && str->ach[i] <= 'z') {
-			str->ach[i] = 'A' + (str->ach[i] - 'a');
+		if (str->ach[i] == '.') {
+			++dots;
+		}
+		else {
+			if (illegal_char(str->ach[i])) {
+				ret = false;
+			}
+			else {
+				str->ach[i] = nls_toupper(str->ach[i]);
+			}
 		}
 	}
+
+	return ret && (dots <= 1);
 }
 
 /** Tries to do some very simple heuristics to convert DOS-style wildcards
@@ -270,16 +335,16 @@ static void fix_wildcards(SHFLSTRING *str)
 static void copy_drive_relative_filename(SHFLSTRING *str, const char __far *path)
 {
 	// Assume X:.... path for now, i.e. drive_relative path starts at char 2
-	shflstring_strcpy(str, path + 2);
+	str->u16Length = local_to_utf8( &data, str->ach, path + 2, str->u16Size );
 }
 
 static void copy_drive_relative_dirname(SHFLSTRING *str, const char __far *path)
 {
 	int last_sep = my_strrchr(path + 2, '\\');
 	if (last_sep >= 0) {
-		shflstring_strncpy(str, path + 2, last_sep == 0 ? 1 : last_sep);
+		str->u16Length = local_to_utf8_n( &data, str->ach, path + 2, str->u16Size, last_sep == 0 ? 1 : last_sep );
 	} else {
-		shflstring_strcpy(str, path + 2);
+		str->u16Length = local_to_utf8( &data, str->ach, path + 2, str->u16Size );
 	}
 }
 
@@ -473,7 +538,6 @@ static void handle_create_open_ex(union INTPACK __far *r)
 	}
 
 	copy_drive_relative_filename(&shflstr.shflstr, path);
-	translate_filename_to_host(&shflstr.shflstr);
 
 	memset(&parms.create, 0, sizeof(SHFLCREATEPARMS));
 	if (action & OPENEX_REPLACE_IF_EXISTS) {
@@ -801,7 +865,6 @@ static void handle_delete(union INTPACK __far *r)
 	dprintf("handle_delete %Fs\n", path);
 
 	copy_drive_relative_filename(&shflstr.shflstr, path);
-	translate_filename_to_host(&shflstr.shflstr);
 
 	err = vbox_shfl_remove(&data.vb, data.hgcm_client_id, root,
 	                       &shflstr.shflstr, SHFL_REMOVE_FILE);
@@ -830,11 +893,9 @@ static void handle_rename(union INTPACK __far *r)
 	}
 
 	copy_drive_relative_filename(&shflstr.shflstr, src);
-	translate_filename_to_host(&shflstr.shflstr);
 
 	// Reusing shfldirinfo buffer space here for our second filename
 	copy_drive_relative_filename(&shfldirinfo.dirinfo.name, dst);
-	translate_filename_to_host(&shfldirinfo.dirinfo.name);
 
 	err = vbox_shfl_rename(&data.vb, data.hgcm_client_id, root,
 	                       &shflstr.shflstr, &shfldirinfo.dirinfo.name,
@@ -857,7 +918,6 @@ static void handle_getattr(union INTPACK __far *r)
 	dprintf("handle_getattr %Fs\n", path);
 
 	copy_drive_relative_filename(&shflstr.shflstr, path);
-	translate_filename_to_host(&shflstr.shflstr);
 
 	memset(&parms.create, 0, sizeof(SHFLCREATEPARMS));
 	parms.create.CreateFlags = SHFL_CF_LOOKUP;
@@ -900,7 +960,6 @@ static vboxerr open_search_dir(unsigned openfile, SHFLROOT root, const char __fa
 	dprintf("open_search_dir openfile=%u path=%Fs\n", openfile, path);
 
 	copy_drive_relative_dirname(&shflstr.shflstr, path);
-	translate_filename_to_host(&shflstr.shflstr);
 
 	memset(&parms.create, 0, sizeof(SHFLCREATEPARMS));
 	parms.create.CreateFlags = SHFL_CF_DIRECTORY
@@ -945,7 +1004,7 @@ static vboxerr find_volume_label(SHFLROOT root)
 	err = vbox_shfl_query_map_name(&data.vb, data.hgcm_client_id, root, &shflstr.shflstr);
 	if (err) return err;
 
-	translate_filename_from_host(&shflstr.shflstr);
+	(void) translate_filename_from_host(&shflstr.shflstr);
 
 	dprintf("label: %s\n", shflstr.buf);
 
@@ -975,7 +1034,6 @@ static vboxerr find_next_from_vbox(unsigned openfile, const char __far *path)
 	// this is what VirtualBox will use in future calls.
 	if (path) {
 		copy_drive_relative_filename(&shflstr.shflstr, path);
-		translate_filename_to_host(&shflstr.shflstr);
 		fix_wildcards(&shflstr.shflstr);
 
 		dprintf("fixed path=%s\n", shflstr.buf);
@@ -1034,7 +1092,10 @@ static vboxerr find_next_from_vbox(unsigned openfile, const char __far *path)
 		// TODO Use the short filename if available from a windows host
 		// i.e. shfldirinfo.dirinfo.cucShortName
 
-		translate_filename_from_host(&shfldirinfo.dirinfo.name);
+		if (!translate_filename_from_host(&shfldirinfo.dirinfo.name)) {
+			dputs("hiding file with illegal character(s)");
+			continue;
+		}
 
 		if (!copy_to_8_3_filename(found_file->filename, &shfldirinfo.dirinfo.name)) {
 			dputs("hiding file with long filename");
@@ -1197,7 +1258,6 @@ static void handle_chdir(union INTPACK __far *r)
 
 	// Just have to check if the directory exists
 	copy_drive_relative_filename(&shflstr.shflstr, path);
-	translate_filename_to_host(&shflstr.shflstr);
 
 	memset(&parms.create, 0, sizeof(SHFLCREATEPARMS));
 	parms.create.CreateFlags = SHFL_CF_LOOKUP;
@@ -1237,7 +1297,6 @@ static void handle_mkdir(union INTPACK __far *r)
 	dprintf("handle_mkdir %Fs\n", path);
 
 	copy_drive_relative_filename(&shflstr.shflstr, path);
-	translate_filename_to_host(&shflstr.shflstr);
 
 	memset(&parms.create, 0, sizeof(SHFLCREATEPARMS));
 	parms.create.CreateFlags = SHFL_CF_DIRECTORY
@@ -1278,7 +1337,6 @@ static void handle_rmdir(union INTPACK __far *r)
 	dprintf("handle_rmdir %Fs\n", path);
 
 	copy_drive_relative_filename(&shflstr.shflstr, path);
-	translate_filename_to_host(&shflstr.shflstr);
 
 	err = vbox_shfl_remove(&data.vb, data.hgcm_client_id, root,
 	                       &shflstr.shflstr, SHFL_REMOVE_DIR);
diff --git a/sftsr.h b/sftsr.h
index 9b254f7..f318bd4 100644
--- a/sftsr.h
+++ b/sftsr.h
@@ -67,6 +67,11 @@ typedef struct {
 	/** Offset (in seconds/2) of the current timezone.
 	 *  As per tradition, a negative offset means east of GMT; while positive means west. */
 	int32_t tz_offset;
+	/** NLS support tables. */
+	uint8_t __far *file_upper_case;
+	FCHAR __far *file_char;
+	/** Codepage to unicode lookup table. */
+	uint16_t unicode_table[128];
 
 	// Current status
 	/** Array of all possible DOS drives. */
diff --git a/unicode.h b/unicode.h
new file mode 100644
index 0000000..9e70895
--- /dev/null
+++ b/unicode.h
@@ -0,0 +1,215 @@
+/*
+ * VBSF - unix to DOS time conversion
+ * Copyright (C) 2022 Javier S. Pedro
+ *
+ * unicode.h: Unicode conversion routines
+ * Copyright (C) 2011-2022 Eduardo Casino
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General License
+ * as published by the Free Software Foundation; either version 2
+ * of the License, or (at your option) any later version.
+
+ * This program 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 License for more details.
+ *
+ * You should have received a copy of the GNU General License
+ * along with this program; if not, write to the Free Software
+ * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301, USA.
+ */
+
+#ifndef UNICODE_H
+#define UNICODE_H
+
+#include <stdint.h>
+#include "sftsr.h"
+
+
+#ifdef __IN_SFTSR__
+#define TSRDATAPTR PTSRDATA
+#else
+#define TSRDATAPTR LPTSRDATA
+#endif
+
+static inline uint8_t lookup_codepage( TSRDATAPTR data, uint16_t cp )
+{
+	uint8_t i;
+	
+	for ( i = 0; i < 128 && data->unicode_table[i] != cp; ++i );
+	
+	return ( i < 128 ? (uint8_t) i + 128 : '\0' );
+}
+
+// dst and src CAN'T BE THE SAME !!!!
+// Returns resulting length or -1 if buffer overflow
+//
+static uint16_t local_to_utf8_n( TSRDATAPTR data, uint8_t *dst, const char far *src, uint16_t buflen, uint16_t count )
+{
+	uint16_t len = 0;	// Resulting length
+	uint16_t cp;	// Unicode Code Point
+
+	while ( *src && count )
+	{
+		// UTF-8 bytes: 0xxxxxxx
+		// Binary CP:   0xxxxxxx
+		// CP range:    U+0000 to U+007F (Direct ASCII translation)
+		//
+		if ( ! (*src & 0x80) )
+		{	
+			if ( buflen > len )
+			{
+				*dst++ = *src;
+				++len;
+				goto cont;
+			}
+			else
+			{
+				return -1;
+			}
+		} 
+
+		cp = data->unicode_table[*src - 128];
+		
+		// UTF-8 bytes: 110yyyyy 10xxxxxx
+		// Binary CP:   00000yyy yyxxxxxx
+		// CP range:    U+0080 to U+07FF
+		//		
+		if ( ! (cp & 0xF000) )
+		{
+			if ( buflen > len + 1 )
+			{
+				*dst++ = (uint8_t)( cp >> 6 ) | 0xC0;
+				*dst++ = (uint8_t)( cp & 0x3f ) | 0x80;
+				len += 2;
+			}
+			else
+			{
+				return -1;
+			}
+		}
+				
+		// UTF-8 bytes: 1110zzzz 10yyyyyy 10xxxxxx
+		// Binary CP:   zzzzyyyy yyxxxxxx
+		// CP range:    U+0800 to U+FFFF
+		//
+		else
+		{
+			if ( buflen > len +2 )
+			{
+				*dst++ = (uint8_t)( cp >> 12 ) | 0xE0;
+				*dst++ = (uint8_t)( (cp >> 6) & 0x3F ) | 0x80;
+				*dst++ = (uint8_t)( cp & 0x3F ) | 0x80;
+				len += 3;
+			}
+			else
+			{
+				return -1;
+			}
+		}
+cont:
+		++src, --count;
+	};
+
+	// Terminate string
+	//
+	*dst = '\0';
+	
+	return len;
+	
+}
+
+static inline uint16_t local_to_utf8( TSRDATAPTR data, uint8_t *dst, const char far *src, uint16_t buflen )
+{
+	return local_to_utf8_n( data, dst, src, buflen, buflen );
+}
+
+// Returns true on success, false if any unsupported char is found
+//
+static bool utf8_to_local( TSRDATAPTR data, char *dst, char *src, uint16_t *len )
+{
+	bool ret = true;	// Return code
+	uint16_t cp;		// Unicode Code point
+	uint16_t l = 0;
+
+	while ( *src )
+	{
+		// UTF-8 bytes: 0xxxxxxx
+		// Binary CP:   0xxxxxxx
+		// CP range:    U+0000 to U+007F (Direct ASCII translation)
+		//
+		if ( ! (*src & 0x80) )
+		{	
+			*dst = *src;
+			++src;
+			goto cont;
+		} 
+		
+		// UTF-8 bytes: 110yyyyy 10xxxxxx
+		// Binary CP:   00000yyy yyxxxxxx
+		// CP range:    U+0080 to U+07FF
+		//
+		if ( ! (*src & 0x20) ) 
+		{
+			cp = ( (uint16_t)(*src & 0x1F) << 6 ) | *(src+1) & 0x3F;
+			*dst = lookup_codepage( data, cp );
+			if ( *dst == '\0' )
+			{
+				*dst = '_';
+				ret = false;
+			}
+			src += 2;
+			goto cont;
+		}
+		
+		// UTF-8 bytes: 1110zzzz 10yyyyyy 10xxxxxx
+		// Binary CP:   zzzzyyyy yyxxxxxx
+		// CP range:    U+0800 to U+FFFF
+		//
+		if ( ! (*src & 0x10) )
+		{
+			cp = ( (uint16_t)(*src & 0xF) << 12 ) | ( (uint16_t)(*(src+1) & 0x3F) << 6 ) | *(src+2) & 0x3F;
+			*dst = lookup_codepage( data, cp );
+			if ( *dst == '\0' )
+			{
+				*dst = '_';
+				ret = false;
+			}
+			src += 3;
+			goto cont;
+		}
+		
+		// UTF-8 bytes: 11110www 10zzzzzz 10yyyyyy 10xxxxxx
+		// Binary CP:   000wwwzz zzzzyyyy yyxxxxxx
+		// CP range:    U+010000 to U+10FFFF
+		//
+		if ( ! (*src & 0x08) )
+		{
+			*dst = '_';		// Currently unsupported
+			ret = false;
+			src += 4;
+			goto cont;
+		}
+		
+		// Should not reach here
+		//
+		*dst = '_';
+		ret = false;
+		++src;
+cont:
+		++dst, ++l;
+		
+	};
+	
+	// Terminate string
+	//
+	*dst = '\0';
+
+	if (len) *len = l;
+
+	return ret;
+
+}
+
+#endif