console: Add support for using EC-3PO console.

This commit introduces a new CONFIG_* option.  To utilise the
experimental console, simply define the following config option in the
board's board.h file.

     #define CONFIG_EXPERIMENTAL_CONSOLE

This is a temporary option which allows the EC console to be work with
the EC-3PO interactive console interface.  When this option is enabled,
the EC expects commands to packed in a particular format.  This is for
command integrity and allows the interpreter to perform automatic
command retrying in the event that a character is dropped from the sent
command.

It also removes a lot of the console editing methods since they are now
being served by EC-3PO.

Once the EC-3PO interpreter is pulled into servod, we can enable this
feature by default and the config option can go away.

BUG=chrome-os-partner:46054
BRANCH=None
TEST=make -j buildall tests
TEST=Enable CONFIG_EXPERIMENTAL_CONSOLE on GLaDOS; Flash EC and verify
that console works via the EC-3PO interactive console interface.
TEST=Build and flash on GLaDOS and verify normal console operation on
standard EC UART.

CQ-DEPEND=CL:308615

Change-Id: I5e66eb94e31299b27ce029b7f7ce6ba0a7fb6816
Signed-off-by: Aseda Aboagye <aaboagye@google.com>
Reviewed-on: https://chromium-review.googlesource.com/309991
Commit-Ready: Aseda Aboagye <aaboagye@chromium.org>
Tested-by: Aseda Aboagye <aaboagye@chromium.org>
Reviewed-by: Randall Spangler <rspangler@chromium.org>

4 files changed, 105 insertions, 1 deletions

diff --git a/Makefile b/Makefile
index bac644327f..40bf8682ed 100644
--- a/Makefile
+++ b/Makefile
@@ -175,7 +175,7 @@ deps := $(ro-deps) $(rw-deps)
 $(config): $(out)/$(PROJECT).bin
 	@printf '%s=y\n' $(_tsk_cfg) $(_flag_cfg) > $@
 
-def_all_deps:=utils ro rw $(config) $(PROJECT_EXTRA)
+def_all_deps:=utils ro rw notice $(config) $(PROJECT_EXTRA)
 all_deps?=$(def_all_deps)
 all: $(all_deps)
 
diff --git a/Makefile.rules b/Makefile.rules
index 23d743fbdb..425a5e84ef 100644
--- a/Makefile.rules
+++ b/Makefile.rules
@@ -95,6 +95,17 @@ buildall:
 	@touch .tests-passed
 	@echo "$@ completed successfully!"
 
+# Print any important notices at the end of the build.
+.PHONY: notice
+notice: $(config)
+ifeq ($(CONFIG_EXPERIMENTAL_CONSOLE),y)
+ifeq ($(TEST_BUILD),)
+	@echo "*** NOTE: The experimental console is ENABLED. ***"
+	@echo "You will need to run the EC-3PO interactive console in the util"
+	@echo "directory!  Otherwise, you won't be able to enter any commands."
+endif # not a TEST_BUILD
+endif # CONFIG_EXPERIMENTAL_CONSOLE=y
+
 proj-%:
 	@echo "======= building $*"; \
 	$(MAKE) --no-print-directory BOARD=$* V=$(V)
diff --git a/common/console.c b/common/console.c
index 3743eae93a..d7365be189 100644
--- a/common/console.c
+++ b/common/console.c
@@ -7,6 +7,9 @@
 
 #include "clock.h"
 #include "console.h"
+#ifdef CONFIG_EXPERIMENTAL_CONSOLE
+#include "crc8.h"
+#endif /* defined(CONFIG_EXPERIMENTAL_CONSOLE) */
 #include "link_defs.h"
 #include "system.h"
 #include "task.h"
@@ -39,6 +42,7 @@ static int input_pos;
 /* Was last received character a carriage return? */
 static int last_rx_was_cr;
 
+#ifndef CONFIG_EXPERIMENTAL_CONSOLE
 /* State of input escape code */
 static enum {
 	ESC_OUTSIDE,   /* Not in escape code */
@@ -49,6 +53,7 @@ static enum {
 	ESC_BRACKET_3, /* Got ESC [ 3 */
 	ESC_O,         /* Got ESC O */
 } esc_state;
+#endif /* !defined(CONFIG_EXPERIMENTAL_CONSOLE) */
 
 /* Extended key code values, from multi-byte escape sequences */
 enum extended_key_code {
@@ -165,9 +170,60 @@ static int handle_command(char *input)
 	char *argv[MAX_ARGS_PER_COMMAND];
 	int argc = 0;
 	int rv;
+#ifdef CONFIG_EXPERIMENTAL_CONSOLE
+	char *e = NULL;
+	int i = 0;
+	int j = 0;
+	int command_len = 0;
+	uint8_t packed_crc8 = 0;
+
+	/* Need to perform some checking to see if our command is intact. */
+
+	/* There's nothing to do if the buffer is empty. */
+	if (!input_len)
+		return EC_SUCCESS;
+
+	/*
+	 * Scan the first two characters in the command string looking for
+	 * ampersands.  We need at least one to continue.
+	 */
+	if ((input_len < 2) || (input[0] != '&' && input[1] != '&'))
+		goto command_has_error;
+
+	/*
+	 * Okay, we've found at least one.  We need to see if we actually got
+	 * 2 ampersands in order to adjust our position properly.
+	 */
+	i = input[1] == '&' ? 2 : 1;
+
+	/* Next, there should be 4 hex digits: XXYY + '&' */
+	if (i+5 > input_len)
+		goto command_has_error;
+	/* Replace the '&' with null so we can call strtoi(). */
+	input[i+4] = 0;
+	j = strtoi(input + i, &e, 16);
+	if (*e)
+		goto command_has_error;
+	/* command length = XX, CRC8 = YY */
+	command_len = j >> 8;
+	packed_crc8 = (uint8_t)j;
+	i += 5;
+
+	/* Lastly, verify the CRC8 of the command. */
+	if (i+command_len > input_len)
+		goto command_has_error;
+	if (packed_crc8 != crc8(&input[i], command_len)) {
+command_has_error:
+		/* Send back the error string. */
+		ccprintf("&&EE\n");
+		return EC_ERROR_UNKNOWN;
+	}
 
 	/* Split input into words.  Ignore words past our limit. */
+	split_words(&input[i], &argc, argv);
+#else
 	split_words(input, &argc, argv);
+#endif /* defined(CONFIG_EXPERIMENTAL_CONSOLE) */
 
 	/* If no command, nothing to do */
 	if (!argc)
@@ -215,6 +271,7 @@ static int console_putc(int c)
 	return rv1 == EC_SUCCESS ? rv2 : rv1;
 }
 
+#ifndef CONFIG_EXPERIMENTAL_CONSOLE
 static void move_cursor_right(void)
 {
 	if (input_pos == input_len)
@@ -250,6 +307,7 @@ static void move_cursor_begin(void)
 	ccprintf("\x1b[%dD", input_pos);
 	input_pos = 0;
 }
+#endif /* !defined(CONFIG_EXPERIMENTAL_CONSOLE) */
 
 static void repeat_char(char c, int cnt)
 {
@@ -293,6 +351,7 @@ static void save_history(void)
 
 #endif /* CONFIG_CONSOLE_HISTORY */
 
+#ifndef CONFIG_EXPERIMENTAL_CONSOLE
 static void handle_backspace(void)
 {
 	if (!input_pos)
@@ -384,6 +443,7 @@ static int handle_esc(int c)
 
 	return -1;
 }
+#endif /* !defined(CONFIG_EXPERIMENTAL_CONSOLE) */
 
 static void console_handle_char(int c)
 {
@@ -398,6 +458,7 @@ static void console_handle_char(int c)
 		last_rx_was_cr = 0;
 	}
 
+#ifndef CONFIG_EXPERIMENTAL_CONSOLE
 	/* Handle terminal escape sequences (ESC [ ...) */
 	if (c == 0x1B) {
 		esc_state = ESC_START;
@@ -407,8 +468,10 @@ static void console_handle_char(int c)
 		if (c != -1)
 			esc_state = ESC_OUTSIDE;
 	}
+#endif /* !defined(CONFIG_EXPERIMENTAL_CONSOLE) */
 
 	switch (c) {
+#ifndef CONFIG_EXPERIMENTAL_CONSOLE
 	case KEY_DEL:
 		if (input_pos == input_len)
 			break;  /* Already at end */
@@ -420,10 +483,13 @@ static void console_handle_char(int c)
 	case 0x7f:
 		handle_backspace();
 		break;
+#endif /* !defined(CONFIG_EXPERIMENTAL_CONSOLE) */
 
 	case '\n':
+#ifndef CONFIG_EXPERIMENTAL_CONSOLE
 		/* Terminate this line */
 		console_putc('\n');
+#endif /* !defined(CONFIG_EXPERIMENTAL_CONSOLE) */
 
 #ifdef CONFIG_CONSOLE_HISTORY
 		/* Save command in history buffer */
@@ -442,10 +508,13 @@ static void console_handle_char(int c)
 		input_pos = input_len = 0;
 		input_buf[0] = '\0';
 
+#ifndef CONFIG_EXPERIMENTAL_CONSOLE
 		/* Reprint prompt */
 		ccputs(PROMPT);
+#endif /* !defined(CONFIG_EXPERIMENTAL_CONSOLE) */
 		break;
 
+#ifndef CONFIG_EXPERIMENTAL_CONSOLE
 	case CTRL('A'):
 	case KEY_HOME:
 		move_cursor_begin();
@@ -511,18 +580,21 @@ static void console_handle_char(int c)
 		break;
 
 #endif /* CONFIG_CONSOLE_HISTORY */
+#endif /* !defined(CONFIG_EXPERIMENTAL_CONSOLE) */
 
 	default:
 		/* Ignore non-printing characters */
 		if (!isprint(c))
 			break;
 
+#ifndef CONFIG_EXPERIMENTAL_CONSOLE
 		/* Ignore if line is full (leaving room for terminating null) */
 		if (input_len >= sizeof(input_buf) - 1)
 			break;
 
 		/* Print character */
 		console_putc(c);
+#endif /* !defined(CONFIG_EXPERIMENTAL_CONSOLE) */
 
 		/* If not at end of line, print rest of line and move it down */
 		if (input_pos != input_len) {
diff --git a/include/config.h b/include/config.h
index afe8eab5d0..c396517a4a 100644
--- a/include/config.h
+++ b/include/config.h
@@ -602,6 +602,15 @@
  */
 #undef CONFIG_CONSOLE_RESTRICTED_INPUT
 
+/*
+ * Enable the experimental console.
+ *
+ * NOTE: If you enable this experimental console, you will need to run the
+ * EC-3PO interactive console in the util directory!  Otherwise, you won't be
+ * able to enter any commands.
+ */
+#undef CONFIG_EXPERIMENTAL_CONSOLE
+
 /* Include CRC-8 utility function */
 #undef CONFIG_CRC8
 
@@ -2008,6 +2017,18 @@
 #include "config_chip.h"
 #include "board.h"
 
+/******************************************************************************/
+/*
+ * Disable the built-in console history if using the experimental console.
+ *
+ * The experimental console keeps its own session-persistent history which
+ * survives EC reboot.  It also requires CRC8 for command integrity.
+ */
+#ifdef CONFIG_EXPERIMENTAL_CONSOLE
+#undef CONFIG_CONSOLE_HISTORY
+#define CONFIG_CRC8
+#endif /* defined(CONFIG_EXPERIMENTAL_CONSOLE) */
+
 /*****************************************************************************/
 /*
  * Handle task-dependent configs.