barebox remote control

This adds the ability to control barebox over serial lines. The regular
console is designed for human input and is unsuitable for controlling
barebox from scripts since characters can be lost on both ends, the data
stream contains escape sequences and the prompt cannot be easily matched
upon.
This approach is based on the RATP protocol. RATP packages start with a
binary 0x01 which does not occur in normal console data. Whenever a
0x01 character is detected in the console barebox goes into RATP mode.
The RATP packets contain a simple structure with a command/respone
type and data for that type. Currently defined types are:

BB_RATP_TYPE_COMMAND (host->barebox):
	Execute a command in the shell
BB_RATP_TYPE_COMMAND_RETURN (barebox->host)
	Sends return value of the command back to the host, also means
	barebox is ready for the next command
BB_RATP_TYPE_CONSOLEMSG (barebox->host)
	Console message from barebox

Planned but not yet implemented are:

BB_RATP_TYPE_PING (host->barebox)
BB_RATP_TYPE_PONG (barebox->host)
	For testing purposes
BB_RATP_TYPE_GETENV (host->barebox)
BB_RATP_TYPE_GETENV_RETURN (barebox->host)
	Get values of environment variables

Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de>
Tested-by: Andrey Smirnov <andrew.smirnov@gmail.com>

1 files changed, 15 insertions, 0 deletions

diff --git a/include/ratp_bb.h b/include/ratp_bb.h
new file mode 100644
index 0000000000..52ecaff374
--- /dev/null
+++ b/include/ratp_bb.h
@@ -0,0 +1,15 @@
+#ifndef __RATP_BB_H
+#define __RATP_BB_H
+
+struct ratp_bb_pkt {
+	struct list_head list;
+
+	unsigned int len;
+	uint8_t data[];
+};
+
+int barebox_ratp(struct console_device *cdev);
+int barebox_ratp_fs_call(struct ratp_bb_pkt *tx, struct ratp_bb_pkt **rx);
+int barebox_ratp_fs_mount(const char *path);
+
+#endif /* __RATP_BB_H */