bios: add auto completion for commands

litex/soc/software/bios/Makefile

@@ -19,6 +19,7 @@ boot-helper-$(CPU).o \
 boot.o \
 readline.o \
 helpers.o \
+complete.o \
 cmd_mem_access.o \
 cmd_spi_flash.o \
 cmd_bios.o \
@@ -42,7 +43,6 @@ endif
 
 bios.elf: $(BIOS_DIRECTORY)/linker.ld $(OBJECTS)
 
-
 %.elf: ../libbase/crt0-$(CPU)-ctr.o ../libnet/libnet.a ../libbase/libbase-nofloat.a ../libcompiler_rt/libcompiler_rt.a
 	$(LD) $(LDFLAGS) -T $(BIOS_DIRECTORY)/linker.ld -N -o $@ \
 		../libbase/crt0-$(CPU)-ctr.o \

litex/soc/software/bios/command.h

@@ -2,6 +2,8 @@
 #define __COMMAND_H__
 
 #define MAX_PARAM	8
+#define CMD_MAX_SIZE	32	/* Used in string list, complete.c */
+#define MAX_CMDS	40	/* Used in string list, complete.c */
 
 struct command_struct {
 	void (*func)(int nb_params, char **params);

litex/soc/software/bios/complete.c

@@ -0,0 +1,174 @@
+// This file is Copyright (c) 2020 Franck Jullien <franck.jullien@gmail.com>
+//
+//     Largely inspired/copied from U-boot and Barebox projects wich are:
+//         Sascha Hauer, Pengutronix, <s.hauer@pengutronix.de>
+
+// License: BSD
+
+#include <stdlib.h>
+#include <stdio.h>
+#include <string.h>
+
+#include "readline.h"
+#include "helpers.h"
+#include "command.h"
+#include "complete.h"
+
+static int tab_pressed = 0;
+
+char sl[MAX_CMDS][CMD_MAX_SIZE];
+int sl_idx = 0;
+
+char out[CMD_MAX_SIZE];
+
+static void string_list_init(void)
+{
+	int i;
+	for (i = 0; i < MAX_CMDS; i++)
+		sl[i][0] = 0;
+}
+
+static int string_list_add(const char *string)
+{
+	int i;
+	for (i = 0; i < MAX_CMDS; i++) {
+		if (sl[i][0] == 0) {
+			strncpy(&sl[i][0], string, CMD_MAX_SIZE);
+			return 0;
+		}
+	}
+	return -1;
+}
+
+static int string_list_empty(void)
+{
+	int i;
+	for (i = 0; i < MAX_CMDS; i++)
+		if (sl[i][0] != 0)
+			return 0;
+	return 1;
+}
+
+static int string_list_count(void)
+{
+	int i, count = 0;
+	for (i = 0; i < MAX_CMDS; i++)
+		if (sl[i][0] != 0)
+			count++;
+	return count;
+}
+
+static char *list_first_entry(void)
+{
+	int i;
+	for (i = 0; i < MAX_CMDS; i++)
+		if (sl[i][0] != 0)
+			return &sl[i][0];
+	return NULL;
+}
+
+static void string_list_print_by_column(void)
+{
+	int len = 0, num, i, j;
+
+	for (i = 0; i < MAX_CMDS; i++) {
+		if (sl[i][0] != 0) {
+			int l = strlen(&sl[i][0]) + 4;
+			if (l > len)
+				len = l;
+		}
+	}
+
+	if (!len)
+		return;
+
+	num = 80 / (len + 1);
+
+	for (j = 0; j < MAX_CMDS; j++) {
+		if (sl[j][0] != 0) {
+			if (!(++i % num))
+				printf("%s\n", &sl[j][0]);
+			else
+				printf("%-*s", len, &sl[j][0]);
+		}
+	}
+	if (i % num)
+		printf("\n");
+}
+
+static void command_complete(char *instr)
+{
+	struct command_struct * const *cmd;
+
+	for (cmd = __bios_cmd_start; cmd != __bios_cmd_end; cmd++)
+		if (!strncmp(instr, (*cmd)->name, strlen(instr)))
+			string_list_add((*cmd)->name);
+}
+
+int complete(char *instr, char **outstr)
+{
+	int pos;
+	char ch;
+	int changed;
+	int outpos = 0;
+	int reprint = 0;
+	char *first_entry;
+	char *entry;
+	int i;
+
+	string_list_init();
+	command_complete(instr);
+
+	pos = strlen(instr);
+
+	*outstr = "";
+	if (string_list_empty())
+		reprint = 0;
+	else
+	{
+		out[0] = 0;
+
+		first_entry = list_first_entry();
+
+		while (1) {
+			entry = first_entry;
+			ch = entry[pos];
+			if (!ch)
+				break;
+
+			changed = 0;
+			for (i = 0; i < MAX_CMDS; i++) {
+				if (sl[i][0] != 0) {
+					if (!sl[i][pos])
+						break;
+					if (ch != sl[i][pos]) {
+						changed = 1;
+						break;
+					}
+				}
+			}
+
+			if (changed)
+				break;
+			out[outpos++] = ch;
+			pos++;
+		}
+
+		if ((string_list_count() != 1) && !outpos && tab_pressed) {
+			printf("\n");
+			string_list_print_by_column();
+			reprint = 1;
+			tab_pressed = 0;
+		}
+
+		out[outpos++] = 0;
+		*outstr = out;
+
+		if (*out == 0)
+			tab_pressed = 1;
+		else
+			tab_pressed = 0;
+	}
+
+	return reprint;
+}

litex/soc/software/bios/complete.h

@@ -0,0 +1,6 @@
+#ifndef __COMPLETE_H__
+#define __COMPLETE_H__
+
+int complete(char *instr, char **outstr);
+
+#endif

litex/soc/software/bios/readline.c

@@ -17,6 +17,7 @@
 #include <uart.h>
 
 #include "readline.h"
+#include "complete.h"
 
 static int hist_max = 0;
 static int hist_add_idx = 0;
@@ -188,6 +189,10 @@ int readline(char *buf, int len)
 	int insert = 1;
 	char ichar;
 
+	char tmp;
+	int reprint, i;
+	char *completestr;
+
 	while (1) {
 
 		ichar = read_key();
@@ -197,6 +202,26 @@ int readline(char *buf, int len)
 
 		switch (ichar) {
 		case '\t':
+			buf[eol_num] = 0;
+			tmp = buf[num];
+
+			buf[num] = 0;
+			reprint = complete(buf, &completestr);
+			buf[num] = tmp;
+
+			if (reprint) {
+				printf("%s%s", PROMPT, buf);
+
+				if (tmp)
+					for (i = 0; i < eol_num - num; i++)
+						getcmd_putch(CTL_BACKSPACE);
+			}
+
+			i = 0;
+			while (completestr[i])
+				cread_add_char(completestr[i++], insert, &num,
+						&eol_num, buf, len);
+
 			break;
 
 		case KEY_HOME: