Yet another major rework of the BusyBox config system, using the considerably
modified Kbuild system I put into uClibc.  With this, there should be no more
need to modify Rules.mak since I've moved all the interesting options into the
config system.  I think I've got everything updated, but you never know, I may
have made some mistakes, so watch closely.
 -Erik
diff --git a/scripts/config/mconf.c b/scripts/config/mconf.c
new file mode 100644
index 0000000..476e78a
--- /dev/null
+++ b/scripts/config/mconf.c
@@ -0,0 +1,669 @@
+/*
+ * Copyright (C) 2002 Roman Zippel <zippel@linux-m68k.org>
+ * Released under the terms of the GNU GPL v2.0.
+ *
+ * Introduced single menu mode (show all sub-menus in one large tree).
+ * 2002-11-06 Petr Baudis <pasky@ucw.cz>
+ *
+ * Directly use liblxdialog library routines.
+ * 2002-11-14 Petr Baudis <pasky@ucw.cz>
+ */
+
+#include <sys/ioctl.h>
+#include <sys/wait.h>
+#include <sys/termios.h>
+#include <ctype.h>
+#include <errno.h>
+#include <fcntl.h>
+#include <limits.h>
+#include <signal.h>
+#include <stdarg.h>
+#include <stdlib.h>
+#include <string.h>
+#include <termios.h>
+#include <unistd.h>
+
+#include "dialog.h"
+
+#define LKC_DIRECT_LINK
+#include "lkc.h"
+
+static const char menu_instructions[] =
+	"Arrow keys navigate the menu.  "
+	"<Enter> selects submenus --->.  "
+	"Highlighted letters are hotkeys.  "
+	"Pressing <Y> selectes a feature, while <N> will exclude a feature.  "
+	"Press <Esc><Esc> to exit, <?> for Help.  "
+	"Legend: [*] feature is selected  [ ] feature is excluded",
+radiolist_instructions[] =
+	"Use the arrow keys to navigate this window or "
+	"press the hotkey of the item you wish to select "
+	"followed by the <SPACE BAR>. "
+	"Press <?> for additional information about this option.",
+inputbox_instructions_int[] =
+	"Please enter a decimal value. "
+	"Fractions will not be accepted.  "
+	"Use the <TAB> key to move from the input field to the buttons below it.",
+inputbox_instructions_hex[] =
+	"Please enter a hexadecimal value. "
+	"Use the <TAB> key to move from the input field to the buttons below it.",
+inputbox_instructions_string[] =
+	"Please enter a string value. "
+	"Use the <TAB> key to move from the input field to the buttons below it.",
+setmod_text[] =
+	"This feature depends on another which has been configured as a module.\n"
+	"As a result, this feature will be built as a module.",
+nohelp_text[] =
+	"There is no help available for this option.\n",
+load_config_text[] =
+	"Enter the name of the configuration file you wish to load.  "
+	"Accept the name shown to restore the configuration you "
+	"last retrieved.  Leave blank to abort.",
+load_config_help[] =
+	"\n"
+	"For various reasons, one may wish to keep several different BusyBox\n"
+	"configurations available on a single machine.\n"
+	"\n"
+	"If you have saved a previous configuration in a file other than the\n"
+	"BusyBox default, entering the name of the file here will allow you\n"
+	"to modify that configuration.\n"
+	"\n"
+	"If you are uncertain, then you have probably never used alternate\n"
+	"configuration files.  You should therefor leave this blank to abort.\n",
+save_config_text[] =
+	"Enter a filename to which this configuration should be saved "
+	"as an alternate.  Leave blank to abort.",
+save_config_help[] =
+	"\n"
+	"For various reasons, one may wish to keep different BusyBox\n"
+	"configurations available on a single machine.\n"
+	"\n"
+	"Entering a file name here will allow you to later retrieve, modify\n"
+	"and use the current configuration as an alternate to whatever\n"
+	"configuration options you have selected at that time.\n"
+	"\n"
+	"If you are uncertain what all this means then you should probably\n"
+	"leave this blank.\n"
+;
+
+static char filename[PATH_MAX+1] = ".config";
+static int indent = 0;
+static struct termios ios_org;
+static int rows, cols;
+static struct menu *current_menu;
+static int child_count;
+static int single_menu_mode;
+
+static struct dialog_list_item *items[16384]; /* FIXME: This ought to be dynamic. */
+static int item_no;
+
+static void conf(struct menu *menu);
+static void conf_choice(struct menu *menu);
+static void conf_string(struct menu *menu);
+static void conf_load(void);
+static void conf_save(void);
+static void show_textbox(const char *title, const char *text, int r, int c);
+static void show_helptext(const char *title, const char *text);
+static void show_help(struct menu *menu);
+static void show_readme(void);
+
+static void init_wsize(void)
+{
+	struct winsize ws;
+
+	if (ioctl(1, TIOCGWINSZ, &ws) == -1) {
+		rows = 24;
+		cols = 80;
+	} else {
+		rows = ws.ws_row;
+		cols = ws.ws_col;
+	}
+
+	if (rows < 19 || cols < 80) {
+		fprintf(stderr, "Your display is too small to run Menuconfig!\n");
+		fprintf(stderr, "It must be at least 19 lines by 80 columns.\n");
+		exit(1);
+	}
+
+	rows -= 4;
+	cols -= 5;
+}
+
+static void cinit(void)
+{
+	item_no = 0;
+}
+
+static void cmake(void)
+{
+	items[item_no] = malloc(sizeof(struct dialog_list_item));
+	memset(items[item_no], 0, sizeof(struct dialog_list_item));
+	items[item_no]->tag = malloc(32); items[item_no]->tag[0] = 0;
+	items[item_no]->name = malloc(512); items[item_no]->name[0] = 0;
+	items[item_no]->namelen = 0;
+	item_no++;
+}
+  
+static int cprint_name(const char *fmt, ...)
+{
+	va_list ap;
+	int res;
+
+	if (!item_no)
+		cmake();
+	va_start(ap, fmt);
+	res = vsnprintf(items[item_no - 1]->name + items[item_no - 1]->namelen,
+			512 - items[item_no - 1]->namelen, fmt, ap);
+	if (res > 0)
+		items[item_no - 1]->namelen += res;
+	va_end(ap);
+
+	return res;
+}
+  
+static int cprint_tag(const char *fmt, ...)
+{
+	va_list ap;
+	int res;
+
+	if (!item_no)
+		cmake();
+	va_start(ap, fmt);
+	res = vsnprintf(items[item_no - 1]->tag, 32, fmt, ap);
+	va_end(ap);
+
+	return res;
+}
+  
+static void cdone(void)
+{
+	int i;
+
+	for (i = 0; i < item_no; i++) {
+		free(items[i]->tag);
+		free(items[i]->name);
+		free(items[i]);
+	}
+
+	item_no = 0;
+}
+
+static void build_conf(struct menu *menu)
+{
+	struct symbol *sym;
+	struct property *prop;
+	struct menu *child;
+	int type, tmp, doint = 2;
+	tristate val;
+	char ch;
+
+	if (!menu_is_visible(menu))
+		return;
+
+	sym = menu->sym;
+	prop = menu->prompt;
+	if (!sym) {
+		if (prop && menu != current_menu) {
+			const char *prompt = menu_get_prompt(menu);
+			switch (prop->type) {
+			case P_MENU:
+				child_count++;
+				cmake();
+				cprint_tag("m%p", menu);
+
+				if (single_menu_mode) {
+					cprint_name("%s%*c%s",
+						menu->data ? "-->" : "++>",
+						indent + 1, ' ', prompt);
+				} else {
+					if (menu->parent != &rootmenu)
+						cprint_name("   %*c", indent + 1, ' ');
+					cprint_name("%s  --->", prompt);
+				}
+
+				if (single_menu_mode && menu->data)
+					goto conf_childs;
+				return;
+			default:
+				if (prompt) {
+					child_count++;
+					cmake();
+					cprint_tag(":%p", menu);
+					cprint_name("---%*c%s", indent + 1, ' ', prompt);
+				}
+			}
+		} else
+			doint = 0;
+		goto conf_childs;
+	}
+
+	cmake();
+	type = sym_get_type(sym);
+	if (sym_is_choice(sym)) {
+		struct symbol *def_sym = sym_get_choice_value(sym);
+		struct menu *def_menu = NULL;
+
+		child_count++;
+		for (child = menu->list; child; child = child->next) {
+			if (menu_is_visible(child) && child->sym == def_sym)
+				def_menu = child;
+		}
+
+		val = sym_get_tristate_value(sym);
+		if (sym_is_changable(sym)) {
+			cprint_tag("t%p", menu);
+			switch (type) {
+			case S_BOOLEAN:
+				cprint_name("[%c]", val == no ? ' ' : '*');
+				break;
+			case S_TRISTATE:
+				switch (val) {
+				case yes: ch = '*'; break;
+				case mod: ch = 'M'; break;
+				default:  ch = ' '; break;
+				}
+				cprint_name("<%c>", ch);
+				break;
+			}
+		} else {
+			cprint_tag("%c%p", def_menu ? 't' : ':', menu);
+			cprint_name("   ");
+		}
+
+		cprint_name("%*c%s", indent + 1, ' ', menu_get_prompt(menu));
+		if (val == yes) {
+			if (def_menu) {
+				cprint_name(" (%s)", menu_get_prompt(def_menu));
+				cprint_name("  --->");
+				if (def_menu->list) {
+					indent += 2;
+					build_conf(def_menu);
+					indent -= 2;
+				}
+			}
+			return;
+		}
+	} else {
+		child_count++;
+		val = sym_get_tristate_value(sym);
+		if (sym_is_choice_value(sym) && val == yes) {
+			cprint_tag(":%p", menu);
+			cprint_name("   ");
+		} else {
+			switch (type) {
+			case S_BOOLEAN:
+				cprint_tag("t%p", menu);
+				cprint_name("[%c]", val == no ? ' ' : '*');
+				break;
+			case S_TRISTATE:
+				cprint_tag("t%p", menu);
+				switch (val) {
+				case yes: ch = '*'; break;
+				case mod: ch = 'M'; break;
+				default:  ch = ' '; break;
+				}
+				cprint_name("<%c>", ch);
+				break;
+			default:
+				cprint_tag("s%p", menu);
+				tmp = cprint_name("(%s)", sym_get_string_value(sym));
+				tmp = indent - tmp + 4;
+				if (tmp < 0)
+					tmp = 0;
+				cprint_name("%*c%s%s", tmp, ' ', menu_get_prompt(menu),
+					sym_has_value(sym) ? "" : " (NEW)");
+				goto conf_childs;
+			}
+		}
+		cprint_name("%*c%s%s", indent + 1, ' ', menu_get_prompt(menu),
+			sym_has_value(sym) ? "" : " (NEW)");
+	}
+
+conf_childs:
+	indent += doint;
+	for (child = menu->list; child; child = child->next)
+		build_conf(child);
+	indent -= doint;
+}
+
+static void conf(struct menu *menu)
+{
+	struct dialog_list_item *active_item = NULL;
+	struct menu *submenu;
+	const char *prompt = menu_get_prompt(menu);
+	struct symbol *sym;
+	char active_entry[40];
+	int stat, type;
+
+	unlink("lxdialog.scrltmp");
+	active_entry[0] = 0;
+	while (1) {
+		indent = 0;
+		child_count = 0;
+  		current_menu = menu;
+		cdone(); cinit();
+		build_conf(menu);
+		if (!child_count)
+			break;
+		if (menu == &rootmenu) {
+			cmake(); cprint_tag(":"); cprint_name("--- ");
+			cmake(); cprint_tag("L"); cprint_name("Load an Alternate Configuration File");
+			cmake(); cprint_tag("S"); cprint_name("Save Configuration to an Alternate File");
+		}
+		dialog_clear();
+		stat = dialog_menu(prompt ? prompt : "Main Menu",
+				menu_instructions, rows, cols, rows - 10,
+				active_entry, item_no, items);
+		if (stat < 0)
+			return;
+
+		if (stat == 1 || stat == 255)
+			break;
+
+		active_item = first_sel_item(item_no, items);
+		if (!active_item)
+			continue;
+		active_item->selected = 0;
+		strncpy(active_entry, active_item->tag, sizeof(active_entry));
+		active_entry[sizeof(active_entry)-1] = 0;
+		type = active_entry[0];
+		if (!type)
+			continue;
+
+		sym = NULL;
+		submenu = NULL;
+		if (sscanf(active_entry + 1, "%p", &submenu) == 1)
+			sym = submenu->sym;
+
+		switch (stat) {
+		case 0:
+			switch (type) {
+			case 'm':
+				if (single_menu_mode)
+					submenu->data = (submenu->data)? NULL : (void *)1;
+				else
+					conf(submenu);
+				break;
+			case 't':
+				if (sym_is_choice(sym) && sym_get_tristate_value(sym) == yes)
+					conf_choice(submenu);
+				break;
+			case 's':
+				conf_string(submenu);
+				break;
+			case 'L':
+				conf_load();
+				break;
+			case 'S':
+				conf_save();
+				break;
+			}
+			break;
+		case 2:
+			if (sym)
+				show_help(submenu);
+			else
+				show_readme();
+			break;
+		case 3:
+			if (type == 't') {
+				if (sym_set_tristate_value(sym, yes))
+					break;
+				if (sym_set_tristate_value(sym, mod))
+					show_textbox(NULL, setmod_text, 6, 74);
+			}
+			break;
+		case 4:
+			if (type == 't')
+				sym_set_tristate_value(sym, no);
+			break;
+		case 5:
+			if (type == 't')
+				sym_set_tristate_value(sym, mod);
+			break;
+		case 6:
+			if (type == 't')
+				sym_toggle_tristate_value(sym);
+			else if (type == 'm')
+				conf(submenu);
+			break;
+		}
+	}
+}
+
+static void show_textbox(const char *title, const char *text, int r, int c)
+{
+	int fd;
+
+	fd = creat(".help.tmp", 0777);
+	write(fd, text, strlen(text));
+	close(fd);
+	while (dialog_textbox(title, ".help.tmp", r, c) < 0)
+		;
+	unlink(".help.tmp");
+}
+
+static void show_helptext(const char *title, const char *text)
+{
+	show_textbox(title, text, rows, cols);
+}
+
+static void show_help(struct menu *menu)
+{
+	const char *help;
+	char *helptext;
+	struct symbol *sym = menu->sym;
+
+	help = sym->help;
+	if (!help)
+		help = nohelp_text;
+	if (sym->name) {
+		helptext = malloc(strlen(sym->name) + strlen(help) + 16);
+		sprintf(helptext, "%s:\n\n%s", sym->name, help);
+		show_helptext(menu_get_prompt(menu), helptext);
+		free(helptext);
+	} else
+		show_helptext(menu_get_prompt(menu), help);
+}
+
+static void show_readme(void)
+{
+	while (dialog_textbox(NULL, "scripts/README.Menuconfig", rows, cols) < 0)
+		;
+}
+
+static void conf_choice(struct menu *menu)
+{
+	const char *prompt = menu_get_prompt(menu);
+	struct menu *child;
+	struct symbol *active;
+
+	while (1) {
+		current_menu = menu;
+		active = sym_get_choice_value(menu->sym);
+		cdone(); cinit();
+		for (child = menu->list; child; child = child->next) {
+			if (!menu_is_visible(child))
+				continue;
+			cmake();
+			cprint_tag("%p", child);
+			cprint_name("%s", menu_get_prompt(child));
+			items[item_no - 1]->selected = (child->sym == active);
+		}
+
+		switch (dialog_checklist(prompt ? prompt : "Main Menu",
+					radiolist_instructions, 15, 70, 6,
+					item_no, items, FLAG_RADIO)) {
+		case 0:
+			if (sscanf(first_sel_item(item_no, items)->tag, "%p", &menu) != 1)
+				break;
+			sym_set_tristate_value(menu->sym, yes);
+			return;
+		case 1:
+			show_help(menu);
+			break;
+		case 255:
+			return;
+		}
+	}
+}
+
+static void conf_string(struct menu *menu)
+{
+	const char *prompt = menu_get_prompt(menu);
+
+	while (1) {
+		char *heading;
+
+		switch (sym_get_type(menu->sym)) {
+		case S_INT:
+			heading = (char *) inputbox_instructions_int;
+			break;
+		case S_HEX:
+			heading = (char *) inputbox_instructions_hex;
+			break;
+		case S_STRING:
+			heading = (char *) inputbox_instructions_string;
+			break;
+		default:
+			heading = "Internal mconf error!";
+			/* panic? */;
+		}
+
+		switch (dialog_inputbox(prompt ? prompt : "Main Menu",
+					heading, 10, 75,
+					sym_get_string_value(menu->sym))) {
+		case 0:
+			if (sym_set_string_value(menu->sym, dialog_input_result))
+				return;
+			show_textbox(NULL, "You have made an invalid entry.", 5, 43);
+			break;
+		case 1:
+			show_help(menu);
+			break;
+		case 255:
+			return;
+		}
+	}
+}
+
+static void conf_load(void)
+{
+	while (1) {
+		switch (dialog_inputbox(NULL, load_config_text, 11, 55,
+					filename)) {
+		case 0:
+			if (!dialog_input_result[0])
+				return;
+			if (!conf_read(dialog_input_result))
+				return;
+			show_textbox(NULL, "File does not exist!", 5, 38);
+			break;
+		case 1:
+			show_helptext("Load Alternate Configuration", load_config_help);
+			break;
+		case 255:
+			return;
+		}
+	}
+}
+
+static void conf_save(void)
+{
+	while (1) {
+		switch (dialog_inputbox(NULL, save_config_text, 11, 55,
+					filename)) {
+		case 0:
+			if (!dialog_input_result[0])
+				return;
+			if (!conf_write(dialog_input_result))
+				return;
+			show_textbox(NULL, "Can't create file!  Probably a nonexistent directory.", 5, 60);
+			break;
+		case 1:
+			show_helptext("Save Alternate Configuration", save_config_help);
+			break;
+		case 255:
+			return;
+		}
+	}
+}
+
+static void conf_cleanup(void)
+{
+	tcsetattr(1, TCSAFLUSH, &ios_org);
+	unlink(".help.tmp");
+	unlink("lxdialog.scrltmp");
+}
+
+static void winch_handler(int sig)
+{
+	struct winsize ws;
+
+	if (ioctl(1, TIOCGWINSZ, &ws) == -1) {
+		rows = 24;
+		cols = 80;
+	} else {
+		rows = ws.ws_row;
+		cols = ws.ws_col;
+	}
+
+	if (rows < 19 || cols < 80) {
+		end_dialog();
+		fprintf(stderr, "Your display is too small to run Menuconfig!\n");
+		fprintf(stderr, "It must be at least 19 lines by 80 columns.\n");
+		exit(1);
+	}
+
+	rows -= 4;
+	cols -= 5;
+
+}
+
+int main(int ac, char **av)
+{
+	int stat;
+	char *mode;
+	struct symbol *sym;
+
+	conf_parse(av[1]);
+	conf_read(NULL);
+
+	backtitle = malloc(128);
+	sym = sym_lookup("VERSION", 0);
+	sym_calc_value(sym);
+	snprintf(backtitle, 128, "BusyBox v%s Configuration",
+		sym_get_string_value(sym));
+
+	mode = getenv("MENUCONFIG_MODE");
+	if (mode) {
+		if (!strcasecmp(mode, "single_menu"))
+			single_menu_mode = 1;
+	}
+  
+	tcgetattr(1, &ios_org);
+	atexit(conf_cleanup);
+	init_wsize();
+	init_dialog();
+	signal(SIGWINCH, winch_handler); 
+	conf(&rootmenu);
+	end_dialog();
+
+	/* Restart dialog to act more like when lxdialog was still separate */
+	init_dialog();
+	do {
+		stat = dialog_yesno(NULL, 
+				"Do you wish to save your new BusyBox configuration?", 5, 60);
+	} while (stat < 0);
+	end_dialog();
+
+	if (stat == 0) {
+		conf_write(NULL);
+		printf("\n\n"
+			"*** End of BusyBox configuration.\n"
+			"*** Check the top-level Makefile for additional configuration options.\n\n");
+	} else
+		printf("\n\nYour BusyBox configuration changes were NOT saved.\n\n");
+
+	return 0;
+}