root / trunk / bootloader / bootloader.c @ 182
History | View | Annotate | Download (6.97 KB)
1 |
#include <avr/io.h> |
---|---|
2 |
#include <avr/boot.h> |
3 |
#include <avr/pgmspace.h> |
4 |
#include <avr/wdt.h> |
5 |
|
6 |
#include <tooltron.h> |
7 |
#include "uart.h" |
8 |
|
9 |
#define TRUE 0 |
10 |
#define FALSE 1 |
11 |
|
12 |
#define ADDR 18 |
13 |
|
14 |
|
15 |
// Error thresholds
|
16 |
#define MAX_TIMEOUT 60000 // Seconds to wait before exiting bootloader mode |
17 |
#define MAX_RETRIES 5 // Number of times to retry before giving up |
18 |
|
19 |
// Memory locations
|
20 |
#define MAIN_ADDR 0x000 // Where the user code starts |
21 |
#define BOOT_START 0x400 // Where the bootloader starts |
22 |
|
23 |
//Status LED
|
24 |
#define LED_DDR DDRB
|
25 |
#define LED_PORT PORTB
|
26 |
#define LED PORTB1
|
27 |
|
28 |
//Function prototypes
|
29 |
void (*main_start)(void) = BOOT_START/2 - 1; |
30 |
|
31 |
// Packet handler states
|
32 |
typedef enum { |
33 |
sd, |
34 |
src, |
35 |
dest, |
36 |
comd, |
37 |
read, |
38 |
cs, |
39 |
ack |
40 |
} state_t; |
41 |
|
42 |
typedef union { |
43 |
uint8_t bytes[2];
|
44 |
int16_t sword; |
45 |
} rjump_t; |
46 |
|
47 |
void init_uart(uint16_t baud) {
|
48 |
// Set baud rate
|
49 |
UBRRH = (uint8_t)(baud>>8);
|
50 |
UBRRL = (uint8_t)baud; |
51 |
|
52 |
// Enable RX/TX
|
53 |
UCSRB = _BV(RXEN) | _BV(TXEN); |
54 |
|
55 |
// Enable the TXEN pin as output
|
56 |
DDRD |= TX_EN; |
57 |
uart_toggle_transmit(UART_TX_OFF); |
58 |
} |
59 |
|
60 |
int8_t uart_get_byte(uint8_t *output_byte) { |
61 |
if (UCSRA & _BV(RXC)) {
|
62 |
*output_byte = UDR; |
63 |
return 0; |
64 |
} else {
|
65 |
return -1; |
66 |
} |
67 |
} |
68 |
|
69 |
void uart_send_byte(uint8_t data) {
|
70 |
//Waits until current transmit is done
|
71 |
while (!(UCSRA & _BV(UDRE)));
|
72 |
|
73 |
// Enable writes and send
|
74 |
uart_toggle_transmit(UART_TX_ON); |
75 |
UDR = data; |
76 |
|
77 |
// Waits until the transmit is done
|
78 |
while(!(UCSRA & _BV(TXC)));
|
79 |
uart_toggle_transmit(UART_TX_OFF); |
80 |
UCSRA |= _BV(TXC); |
81 |
|
82 |
return;
|
83 |
} |
84 |
|
85 |
void uart_toggle_transmit(uint8_t state) {
|
86 |
if (state == UART_TX_ON) {
|
87 |
PORTD |= TX_EN; |
88 |
} else {
|
89 |
PORTD &= ~TX_EN; |
90 |
} |
91 |
} |
92 |
|
93 |
char parse_packet(uint8_t *mbuf) {
|
94 |
uint8_t r; // Byte from the network
|
95 |
uint8_t crc; // Running checksum of the packet
|
96 |
uint8_t cmd; // The command received
|
97 |
uint8_t pos; // Position in the message buffer
|
98 |
uint8_t lim; // Max number of bytes to read into the message buf
|
99 |
state_t state; // State machine
|
100 |
uint16_t count; |
101 |
|
102 |
r = 0;
|
103 |
crc = 0;
|
104 |
cmd = 0;
|
105 |
pos = 0;
|
106 |
lim = 0;
|
107 |
state = sd; |
108 |
count = 0;
|
109 |
|
110 |
while (1) { |
111 |
// Wait for the next byte
|
112 |
while ((uart_get_byte(&r)) < 0) { |
113 |
if (count >= MAX_TIMEOUT) {
|
114 |
return TT_BAD;
|
115 |
} else {
|
116 |
count++; |
117 |
} |
118 |
} |
119 |
|
120 |
switch (state) {
|
121 |
case sd:
|
122 |
if (r == DELIM) {
|
123 |
state = src; |
124 |
} |
125 |
break;
|
126 |
|
127 |
case src:
|
128 |
if (r == DELIM) {
|
129 |
state = src; |
130 |
} else {
|
131 |
crc = r; |
132 |
state = dest; |
133 |
} |
134 |
break;
|
135 |
|
136 |
case dest:
|
137 |
if (r == DELIM) {
|
138 |
state = src; |
139 |
} else if (r == ADDR) { |
140 |
crc ^= r; |
141 |
state = comd; |
142 |
} else {
|
143 |
state = sd; |
144 |
} |
145 |
break;
|
146 |
|
147 |
case comd:
|
148 |
cmd = r; |
149 |
crc ^= r; |
150 |
|
151 |
if (r == DELIM) {
|
152 |
state = src; |
153 |
} else if (r == TT_PROGM) { |
154 |
lim = PROGM_PACKET_SIZE; |
155 |
state = read; |
156 |
} else if (r == TT_PROGD) { |
157 |
lim = PROGD_PACKET_SIZE; |
158 |
state = read; |
159 |
} else {
|
160 |
state = cs; |
161 |
} |
162 |
break;
|
163 |
|
164 |
case read:
|
165 |
mbuf[pos] = r; |
166 |
crc ^= r; |
167 |
pos++; |
168 |
|
169 |
if (pos == lim) {
|
170 |
state = cs; |
171 |
} |
172 |
|
173 |
break;
|
174 |
|
175 |
case cs:
|
176 |
if (r == crc) {
|
177 |
return cmd;
|
178 |
} else {
|
179 |
return TT_BAD;
|
180 |
} |
181 |
|
182 |
break;
|
183 |
|
184 |
default:
|
185 |
return TT_BAD;
|
186 |
} |
187 |
} |
188 |
} |
189 |
|
190 |
void send_packet(uint8_t cmd) {
|
191 |
uart_send_byte(DELIM); |
192 |
uart_send_byte(ADDR); |
193 |
uart_send_byte(SERVER); |
194 |
uart_send_byte(cmd); |
195 |
uart_send_byte(ACK_CRC ^ cmd); |
196 |
} |
197 |
|
198 |
// SPM_PAGESIZE is set to 32 bytes
|
199 |
void onboard_program_write(uint16_t page, uint8_t *buf) {
|
200 |
uint16_t i; |
201 |
|
202 |
boot_page_erase (page); |
203 |
boot_spm_busy_wait (); // Wait until the memory is erased.
|
204 |
|
205 |
for (i=0; i < SPM_PAGESIZE; i+=2){ |
206 |
// Set up little-endian word.
|
207 |
boot_page_fill (page + i, buf[i] | (buf[i+1] <<8)); |
208 |
} |
209 |
|
210 |
boot_page_write (page); // Store buffer in flash page.
|
211 |
boot_spm_busy_wait(); // Wait until the memory is written.
|
212 |
} |
213 |
|
214 |
int main(void) { |
215 |
uint8_t mbuf[PROGD_PACKET_SIZE]; |
216 |
rjump_t jbuf; |
217 |
uint16_t caddr = MAIN_ADDR; |
218 |
uint8_t iteration; |
219 |
uint8_t resp; |
220 |
uint16_t prog_len; |
221 |
uint8_t i; |
222 |
uint8_t retries; |
223 |
|
224 |
retry_jpnt:
|
225 |
iteration = 0;
|
226 |
retries = 0;
|
227 |
|
228 |
// Clear the watchdog timer
|
229 |
MCUSR &= ~_BV(WDRF); |
230 |
wdt_disable(); |
231 |
WDTCSR = 0;
|
232 |
|
233 |
|
234 |
init_uart(51); //MAGIC NUMBER?? |
235 |
|
236 |
//set LED pin as output
|
237 |
LED_DDR |= 0x07;
|
238 |
PORTB = 0x07;
|
239 |
|
240 |
//Start bootloading process
|
241 |
send_packet(TT_BOOT); |
242 |
|
243 |
resp = parse_packet(mbuf); |
244 |
|
245 |
// Enter programming mode
|
246 |
if (resp == TT_PROGM) {
|
247 |
prog_len = mbuf[0];
|
248 |
prog_len |= mbuf[1] << 8; |
249 |
|
250 |
// This will insert a NOP into the user code jump in case
|
251 |
// the programming fails
|
252 |
for (i = 0; i < PROGD_PACKET_SIZE; i++) { |
253 |
mbuf[i]= 0;
|
254 |
} |
255 |
onboard_program_write(BOOT_START - SPM_PAGESIZE, mbuf); |
256 |
|
257 |
// Run user code
|
258 |
} else {
|
259 |
main_start(); |
260 |
} |
261 |
|
262 |
send_packet(TT_ACK); |
263 |
|
264 |
while(1) { |
265 |
resp = parse_packet(mbuf); |
266 |
|
267 |
if (resp == TT_PROGD) {
|
268 |
// We need to muck with the reset vector jump in the first page
|
269 |
if (iteration == 0) { |
270 |
// Store the jump to user code
|
271 |
jbuf.bytes[0] = mbuf[0]; |
272 |
jbuf.bytes[1] = mbuf[1]; |
273 |
|
274 |
// Rewrite the user code jump to be correct since we are
|
275 |
// using relative jumps (rjmp)
|
276 |
jbuf.sword &= 0x0FFF;
|
277 |
jbuf.sword -= (BOOT_START >> 1) - 1; |
278 |
jbuf.sword &= 0x0FFF;
|
279 |
jbuf.sword |= 0xC000;
|
280 |
|
281 |
// Rewrite the reset vector to jump to the bootloader
|
282 |
mbuf[0] = (BOOT_START/2 - 1) & 0xFF; |
283 |
mbuf[1] = 0xC0 | (((BOOT_START/2 - 1) >> 8) & 0x0F); |
284 |
|
285 |
iteration = 1;
|
286 |
} |
287 |
|
288 |
// Write the page to the flash
|
289 |
onboard_program_write(caddr, mbuf); |
290 |
caddr += PROGD_PACKET_SIZE; |
291 |
retries = 0;
|
292 |
} else {
|
293 |
send_packet(TT_NACK); |
294 |
retries++; |
295 |
|
296 |
// If we failed too many times, reset. This goes to the start
|
297 |
// of the bootloader function
|
298 |
if (retries > MAX_RETRIES) {
|
299 |
goto retry_jpnt;
|
300 |
} |
301 |
} |
302 |
|
303 |
send_packet(TT_ACK); |
304 |
|
305 |
// Once we write the last packet we must override the jump to
|
306 |
// user code to point to the correct address
|
307 |
if (prog_len <= PROGD_PACKET_SIZE) {
|
308 |
for (i = 0; i < PROGD_PACKET_SIZE; i++) { |
309 |
mbuf[i]= 0;
|
310 |
} |
311 |
|
312 |
mbuf[PROGD_PACKET_SIZE-2] = jbuf.bytes[0]; |
313 |
mbuf[PROGD_PACKET_SIZE-1] = jbuf.bytes[1]; |
314 |
|
315 |
onboard_program_write(BOOT_START - SPM_PAGESIZE, mbuf); |
316 |
|
317 |
main_start(); |
318 |
} else {
|
319 |
prog_len -= PROGD_PACKET_SIZE; |
320 |
} |
321 |
} |
322 |
|
323 |
// Should never get here
|
324 |
return -1; |
325 |
} |