Initialize.

1 files changed, 150 insertions, 0 deletions

diff --git a/pyecsca/codegen/simpleserial/simpleserial.c b/pyecsca/codegen/simpleserial/simpleserial.c
new file mode 100644
index 0000000..8205ed4
--- /dev/null
+++ b/pyecsca/codegen/simpleserial/simpleserial.c
@@ -0,0 +1,150 @@
+// simpleserial.c
+
+#include "simpleserial.h"
+#include <stdint.h>
+#include "hal.h"
+
+typedef struct ss_cmd
+{
+	char c;
+	unsigned int len;
+	uint8_t (*fp)(uint8_t*, uint16_t);
+} ss_cmd;
+
+#define MAX_SS_CMDS 26
+static ss_cmd commands[MAX_SS_CMDS];
+static int num_commands = 0;
+
+#define MAX_SS_LEN 256
+
+#define SS_VER_1_0 0
+#define SS_VER_1_1 1
+
+static char hex_lookup[16] =
+{
+	'0', '1', '2', '3', '4', '5', '6', '7',
+	'8', '9', 'A', 'B', 'C', 'D', 'E', 'F'
+};
+
+int hex_decode(int len, char* ascii_buf, uint8_t* data_buf)
+{
+	for(int i = 0; i < len; i++)
+	{
+		char n_hi = ascii_buf[2*i];
+		char n_lo = ascii_buf[2*i+1];
+
+		if(n_lo >= '0' && n_lo <= '9')
+			data_buf[i] = n_lo - '0';
+		else if(n_lo >= 'A' && n_lo <= 'F')
+			data_buf[i] = n_lo - 'A' + 10;
+		else if(n_lo >= 'a' && n_lo <= 'f')
+			data_buf[i] = n_lo - 'a' + 10;
+		else
+			return 1;
+
+		if(n_hi >= '0' && n_hi <= '9')
+			data_buf[i] |= (n_hi - '0') << 4;
+		else if(n_hi >= 'A' && n_hi <= 'F')
+			data_buf[i] |= (n_hi - 'A' + 10) << 4;
+		else if(n_hi >= 'a' && n_hi <= 'f')
+			data_buf[i] |= (n_hi - 'a' + 10) << 4;
+		else
+			return 1;
+	}
+
+	return 0;
+}
+
+// Callback function for "v" command.
+// This can exist in v1.0 as long as we don't actually send back an ack ("z")
+uint8_t check_version(uint8_t* v, uint16_t len)
+{
+	return 0x00;
+}
+
+// Set up the SimpleSerial module by preparing internal commands
+// This just adds the "v" command for now...
+void simpleserial_init()
+{
+	simpleserial_addcmd('v', 0, check_version);
+}
+
+int simpleserial_addcmd(char c, unsigned int len, uint8_t (*fp)(uint8_t*, uint16_t))
+{
+	if(num_commands >= MAX_SS_CMDS)
+		return 1;
+
+	if(len > MAX_SS_LEN)
+		return 1;
+
+	commands[num_commands].c   = c;
+	commands[num_commands].len = len;
+	commands[num_commands].fp  = fp;
+	num_commands++;
+
+	return 0;
+}
+
+void simpleserial_get(void)
+{
+	char ascii_buf[2*MAX_SS_LEN];
+	uint8_t data_buf[MAX_SS_LEN];
+	char c;
+
+	// Find which command we're receiving
+	c = getch();
+
+	int cmd;
+	for(cmd = 0; cmd < num_commands; cmd++)
+	{
+		if(commands[cmd].c == c)
+			break;
+	}
+
+	// If we didn't find a match, give up right away
+	if(cmd == num_commands)
+		return;
+
+	// Receive characters until we fill the ASCII buffer
+	int i = 0;
+	for(; i < 2*commands[cmd].len; i++)
+	{
+		c = getch();
+
+		// Check for early \n
+		if(c == '\n' || c == '\r')
+			break;
+
+		ascii_buf[i] = c;
+	}
+
+	// ASCII buffer is full: convert to bytes 
+	// Check for illegal characters here
+	if(hex_decode(i, ascii_buf, data_buf))
+		return;
+
+	// Callback
+	uint8_t ret[1];
+	ret[0] = commands[cmd].fp(data_buf, i);
+	
+	// Acknowledge (if version is 1.1)
+#if SS_VER == SS_VER_1_1
+	simpleserial_put('z', 1, ret);
+#endif
+}
+
+void simpleserial_put(char c, int size, uint8_t* output)
+{
+	// Write first character
+	putch(c);
+
+	// Write each byte as two nibbles
+	for(int i = 0; i < size; i++)
+	{
+		putch(hex_lookup[output[i] >> 4 ]);
+		putch(hex_lookup[output[i] & 0xF]);
+	}
+
+	// Write trailing '\n'
+	putch('\n');
+}