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1 | //----------------------------------------------------------------------------- | |
2 | // Jonathan Westhues, Sept 2005 | |
3 | // | |
4 | // This code is licensed to you under the terms of the GNU GPL, version 2 or, | |
5 | // at your option, any later version. See the LICENSE.txt file for the text of | |
6 | // the license. | |
7 | //----------------------------------------------------------------------------- | |
8 | // Utility functions used in many places, not specific to any piece of code. | |
9 | //----------------------------------------------------------------------------- | |
10 | ||
11 | #include "proxmark3.h" | |
12 | #include "util.h" | |
13 | #include "string.h" | |
14 | #include "apps.h" | |
15 | #include "BigBuf.h" | |
16 | ||
17 | ||
18 | ||
19 | void print_result(char *name, uint8_t *buf, size_t len) { | |
20 | uint8_t *p = buf; | |
21 | ||
22 | if ( len % 16 == 0 ) { | |
23 | for(; p-buf < len; p += 16) | |
24 | Dbprintf("[%s:%d/%d] %02x %02x %02x %02x %02x %02x %02x %02x %02x %02x %02x %02x %02x %02x %02x %02x", | |
25 | name, | |
26 | p-buf, | |
27 | len, | |
28 | p[0], p[1], p[2], p[3], p[4], p[5], p[6], p[7],p[8], p[9], p[10], p[11], p[12], p[13], p[14], p[15] | |
29 | ); | |
30 | } | |
31 | else { | |
32 | for(; p-buf < len; p += 8) | |
33 | Dbprintf("[%s:%d/%d] %02x %02x %02x %02x %02x %02x %02x %02x", name, p-buf, len, p[0], p[1], p[2], p[3], p[4], p[5], p[6], p[7]); | |
34 | } | |
35 | } | |
36 | ||
37 | size_t nbytes(size_t nbits) { | |
38 | return (nbits >> 3)+((nbits % 8) > 0); | |
39 | } | |
40 | ||
41 | uint32_t SwapBits(uint32_t value, int nrbits) { | |
42 | int i; | |
43 | uint32_t newvalue = 0; | |
44 | for(i = 0; i < nrbits; i++) { | |
45 | newvalue ^= ((value >> i) & 1) << (nrbits - 1 - i); | |
46 | } | |
47 | return newvalue; | |
48 | } | |
49 | ||
50 | void num_to_bytes(uint64_t n, size_t len, uint8_t* dest) | |
51 | { | |
52 | while (len--) { | |
53 | dest[len] = (uint8_t) n; | |
54 | n >>= 8; | |
55 | } | |
56 | } | |
57 | ||
58 | uint64_t bytes_to_num(uint8_t* src, size_t len) | |
59 | { | |
60 | uint64_t num = 0; | |
61 | while (len--) | |
62 | { | |
63 | num = (num << 8) | (*src); | |
64 | src++; | |
65 | } | |
66 | return num; | |
67 | } | |
68 | ||
69 | // RotateLeft - Ultralight, Desfire | |
70 | void rol(uint8_t *data, const size_t len){ | |
71 | uint8_t first = data[0]; | |
72 | for (size_t i = 0; i < len-1; i++) { | |
73 | data[i] = data[i+1]; | |
74 | } | |
75 | data[len-1] = first; | |
76 | } | |
77 | void lsl (uint8_t *data, size_t len) { | |
78 | for (size_t n = 0; n < len - 1; n++) { | |
79 | data[n] = (data[n] << 1) | (data[n+1] >> 7); | |
80 | } | |
81 | data[len - 1] <<= 1; | |
82 | } | |
83 | ||
84 | void LEDsoff() | |
85 | { | |
86 | LED_A_OFF(); | |
87 | LED_B_OFF(); | |
88 | LED_C_OFF(); | |
89 | LED_D_OFF(); | |
90 | } | |
91 | ||
92 | // LEDs: R(C) O(A) G(B) -- R(D) [1, 2, 4 and 8] | |
93 | void LED(int led, int ms) | |
94 | { | |
95 | if (led & LED_RED) | |
96 | LED_C_ON(); | |
97 | if (led & LED_ORANGE) | |
98 | LED_A_ON(); | |
99 | if (led & LED_GREEN) | |
100 | LED_B_ON(); | |
101 | if (led & LED_RED2) | |
102 | LED_D_ON(); | |
103 | ||
104 | if (!ms) | |
105 | return; | |
106 | ||
107 | SpinDelay(ms); | |
108 | ||
109 | if (led & LED_RED) | |
110 | LED_C_OFF(); | |
111 | if (led & LED_ORANGE) | |
112 | LED_A_OFF(); | |
113 | if (led & LED_GREEN) | |
114 | LED_B_OFF(); | |
115 | if (led & LED_RED2) | |
116 | LED_D_OFF(); | |
117 | } | |
118 | ||
119 | ||
120 | // Determine if a button is double clicked, single clicked, | |
121 | // not clicked, or held down (for ms || 1sec) | |
122 | // In general, don't use this function unless you expect a | |
123 | // double click, otherwise it will waste 500ms -- use BUTTON_HELD instead | |
124 | int BUTTON_CLICKED(int ms) | |
125 | { | |
126 | // Up to 500ms in between clicks to mean a double click | |
127 | int ticks = (48000 * (ms ? ms : 1000)) >> 10; | |
128 | ||
129 | // If we're not even pressed, forget about it! | |
130 | if (!BUTTON_PRESS()) | |
131 | return BUTTON_NO_CLICK; | |
132 | ||
133 | // Borrow a PWM unit for my real-time clock | |
134 | AT91C_BASE_PWMC->PWMC_ENA = PWM_CHANNEL(0); | |
135 | // 48 MHz / 1024 gives 46.875 kHz | |
136 | AT91C_BASE_PWMC_CH0->PWMC_CMR = PWM_CH_MODE_PRESCALER(10); | |
137 | AT91C_BASE_PWMC_CH0->PWMC_CDTYR = 0; | |
138 | AT91C_BASE_PWMC_CH0->PWMC_CPRDR = 0xffff; | |
139 | ||
140 | uint16_t start = AT91C_BASE_PWMC_CH0->PWMC_CCNTR; | |
141 | ||
142 | int letoff = 0; | |
143 | for(;;) | |
144 | { | |
145 | uint16_t now = AT91C_BASE_PWMC_CH0->PWMC_CCNTR; | |
146 | ||
147 | // We haven't let off the button yet | |
148 | if (!letoff) | |
149 | { | |
150 | // We just let it off! | |
151 | if (!BUTTON_PRESS()) | |
152 | { | |
153 | letoff = 1; | |
154 | ||
155 | // reset our timer for 500ms | |
156 | start = AT91C_BASE_PWMC_CH0->PWMC_CCNTR; | |
157 | ticks = (48000 * (500)) >> 10; | |
158 | } | |
159 | ||
160 | // Still haven't let it off | |
161 | else | |
162 | // Have we held down a full second? | |
163 | if (now == (uint16_t)(start + ticks)) | |
164 | return BUTTON_HOLD; | |
165 | } | |
166 | ||
167 | // We already let off, did we click again? | |
168 | else | |
169 | // Sweet, double click! | |
170 | if (BUTTON_PRESS()) | |
171 | return BUTTON_DOUBLE_CLICK; | |
172 | ||
173 | // Have we ran out of time to double click? | |
174 | else | |
175 | if (now == (uint16_t)(start + ticks)) | |
176 | // At least we did a single click | |
177 | return BUTTON_SINGLE_CLICK; | |
178 | ||
179 | WDT_HIT(); | |
180 | } | |
181 | ||
182 | // We should never get here | |
183 | return BUTTON_ERROR; | |
184 | } | |
185 | ||
186 | // Determine if a button is held down | |
187 | int BUTTON_HELD(int ms) | |
188 | { | |
189 | // If button is held for one second | |
190 | int ticks = (48000 * (ms ? ms : 1000)) >> 10; | |
191 | ||
192 | // If we're not even pressed, forget about it! | |
193 | if (!BUTTON_PRESS()) | |
194 | return BUTTON_NO_CLICK; | |
195 | ||
196 | // Borrow a PWM unit for my real-time clock | |
197 | AT91C_BASE_PWMC->PWMC_ENA = PWM_CHANNEL(0); | |
198 | // 48 MHz / 1024 gives 46.875 kHz | |
199 | AT91C_BASE_PWMC_CH0->PWMC_CMR = PWM_CH_MODE_PRESCALER(10); | |
200 | AT91C_BASE_PWMC_CH0->PWMC_CDTYR = 0; | |
201 | AT91C_BASE_PWMC_CH0->PWMC_CPRDR = 0xffff; | |
202 | ||
203 | uint16_t start = AT91C_BASE_PWMC_CH0->PWMC_CCNTR; | |
204 | ||
205 | for(;;) | |
206 | { | |
207 | uint16_t now = AT91C_BASE_PWMC_CH0->PWMC_CCNTR; | |
208 | ||
209 | // As soon as our button let go, we didn't hold long enough | |
210 | if (!BUTTON_PRESS()) | |
211 | return BUTTON_SINGLE_CLICK; | |
212 | ||
213 | // Have we waited the full second? | |
214 | else | |
215 | if (now == (uint16_t)(start + ticks)) | |
216 | return BUTTON_HOLD; | |
217 | ||
218 | WDT_HIT(); | |
219 | } | |
220 | ||
221 | // We should never get here | |
222 | return BUTTON_ERROR; | |
223 | } | |
224 | ||
225 | // attempt at high resolution microsecond timer | |
226 | // beware: timer counts in 21.3uS increments (1024/48Mhz) | |
227 | void SpinDelayUs(int us) | |
228 | { | |
229 | int ticks = (48*us) >> 10; | |
230 | ||
231 | // Borrow a PWM unit for my real-time clock | |
232 | AT91C_BASE_PWMC->PWMC_ENA = PWM_CHANNEL(0); | |
233 | // 48 MHz / 1024 gives 46.875 kHz | |
234 | AT91C_BASE_PWMC_CH0->PWMC_CMR = PWM_CH_MODE_PRESCALER(10); | |
235 | AT91C_BASE_PWMC_CH0->PWMC_CDTYR = 0; | |
236 | AT91C_BASE_PWMC_CH0->PWMC_CPRDR = 0xffff; | |
237 | ||
238 | uint16_t start = AT91C_BASE_PWMC_CH0->PWMC_CCNTR; | |
239 | ||
240 | for(;;) { | |
241 | uint16_t now = AT91C_BASE_PWMC_CH0->PWMC_CCNTR; | |
242 | if (now == (uint16_t)(start + ticks)) | |
243 | return; | |
244 | ||
245 | WDT_HIT(); | |
246 | } | |
247 | } | |
248 | ||
249 | void SpinDelay(int ms) | |
250 | { | |
251 | // convert to uS and call microsecond delay function | |
252 | SpinDelayUs(ms*1000); | |
253 | } | |
254 | ||
255 | /* Similar to FpgaGatherVersion this formats stored version information | |
256 | * into a string representation. It takes a pointer to the struct version_information, | |
257 | * verifies the magic properties, then stores a formatted string, prefixed by | |
258 | * prefix in dst. | |
259 | */ | |
260 | void FormatVersionInformation(char *dst, int len, const char *prefix, void *version_information) | |
261 | { | |
262 | struct version_information *v = (struct version_information*)version_information; | |
263 | dst[0] = 0; | |
264 | strncat(dst, prefix, len-1); | |
265 | if(v->magic != VERSION_INFORMATION_MAGIC) { | |
266 | strncat(dst, "Missing/Invalid version information\n", len - strlen(dst) - 1); | |
267 | return; | |
268 | } | |
269 | if(v->versionversion != 1) { | |
270 | strncat(dst, "Version information not understood\n", len - strlen(dst) - 1); | |
271 | return; | |
272 | } | |
273 | if(!v->present) { | |
274 | strncat(dst, "Version information not available\n", len - strlen(dst) - 1); | |
275 | return; | |
276 | } | |
277 | ||
278 | strncat(dst, v->gitversion, len - strlen(dst) - 1); | |
279 | if(v->clean == 0) { | |
280 | strncat(dst, "-unclean", len - strlen(dst) - 1); | |
281 | } else if(v->clean == 2) { | |
282 | strncat(dst, "-suspect", len - strlen(dst) - 1); | |
283 | } | |
284 | ||
285 | strncat(dst, " ", len - strlen(dst) - 1); | |
286 | strncat(dst, v->buildtime, len - strlen(dst) - 1); | |
287 | strncat(dst, "\n", len - strlen(dst) - 1); | |
288 | } | |
289 | ||
290 | ||
291 | // ------------------------------------------------------------------------- | |
292 | // timer lib | |
293 | // ------------------------------------------------------------------------- | |
294 | // test procedure: | |
295 | // | |
296 | // ti = GetTickCount(); | |
297 | // SpinDelay(1000); | |
298 | // ti = GetTickCount() - ti; | |
299 | // Dbprintf("timer(1s): %d t=%d", ti, GetTickCount()); | |
300 | ||
301 | void StartTickCount() | |
302 | { | |
303 | // This timer is based on the slow clock. The slow clock frequency is between 22kHz and 40kHz. | |
304 | // We can determine the actual slow clock frequency by looking at the Main Clock Frequency Register. | |
305 | uint16_t mainf = AT91C_BASE_PMC->PMC_MCFR & 0xffff; // = 16 * main clock frequency (16MHz) / slow clock frequency | |
306 | // set RealTimeCounter divider to count at 1kHz: | |
307 | AT91C_BASE_RTTC->RTTC_RTMR = AT91C_RTTC_RTTRST | ((256000 + (mainf/2)) / mainf); | |
308 | // note: worst case precision is approx 2.5% | |
309 | } | |
310 | ||
311 | ||
312 | /* | |
313 | * Get the current count. | |
314 | */ | |
315 | uint32_t RAMFUNC GetTickCount(){ | |
316 | return AT91C_BASE_RTTC->RTTC_RTVR;// was * 2; | |
317 | } | |
318 | ||
319 | ||
320 | // ------------------------------------------------------------------------- | |
321 | // microseconds timer | |
322 | // ------------------------------------------------------------------------- | |
323 | void StartCountUS() | |
324 | { | |
325 | AT91C_BASE_PMC->PMC_PCER |= (0x1 << 12) | (0x1 << 13) | (0x1 << 14); | |
326 | // AT91C_BASE_TCB->TCB_BMR = AT91C_TCB_TC1XC1S_TIOA0; | |
327 | AT91C_BASE_TCB->TCB_BMR = AT91C_TCB_TC0XC0S_NONE | AT91C_TCB_TC1XC1S_TIOA0 | AT91C_TCB_TC2XC2S_NONE; | |
328 | ||
329 | // fast clock | |
330 | AT91C_BASE_TC0->TC_CCR = AT91C_TC_CLKDIS; // timer disable | |
331 | AT91C_BASE_TC0->TC_CMR = AT91C_TC_CLKS_TIMER_DIV3_CLOCK | // MCK(48MHz)/32 -- tick=1.5mks | |
332 | AT91C_TC_WAVE | AT91C_TC_WAVESEL_UP_AUTO | AT91C_TC_ACPA_CLEAR | | |
333 | AT91C_TC_ACPC_SET | AT91C_TC_ASWTRG_SET; | |
334 | AT91C_BASE_TC0->TC_RA = 1; | |
335 | AT91C_BASE_TC0->TC_RC = 0xBFFF + 1; // 0xC000 | |
336 | ||
337 | AT91C_BASE_TC1->TC_CCR = AT91C_TC_CLKDIS; // timer disable | |
338 | AT91C_BASE_TC1->TC_CMR = AT91C_TC_CLKS_XC1; // from timer 0 | |
339 | ||
340 | AT91C_BASE_TC0->TC_CCR = AT91C_TC_CLKEN; | |
341 | AT91C_BASE_TC1->TC_CCR = AT91C_TC_CLKEN; | |
342 | AT91C_BASE_TCB->TCB_BCR = 1; | |
343 | } | |
344 | ||
345 | ||
346 | uint32_t RAMFUNC GetCountUS(){ | |
347 | return (AT91C_BASE_TC1->TC_CV * 0x8000) + ((AT91C_BASE_TC0->TC_CV * 2) / 3); //was /15) * 10); | |
348 | } | |
349 | ||
350 | ||
351 | static uint32_t GlobalUsCounter = 0; | |
352 | ||
353 | uint32_t RAMFUNC GetDeltaCountUS(){ | |
354 | uint32_t g_cnt = GetCountUS(); | |
355 | uint32_t g_res = g_cnt - GlobalUsCounter; | |
356 | GlobalUsCounter = g_cnt; | |
357 | return g_res; | |
358 | } | |
359 | ||
360 | ||
361 | // ------------------------------------------------------------------------- | |
362 | // Timer for iso14443 commands. Uses ssp_clk from FPGA | |
363 | // ------------------------------------------------------------------------- | |
364 | void StartCountSspClk() | |
365 | { | |
366 | AT91C_BASE_PMC->PMC_PCER = (1 << AT91C_ID_TC0) | (1 << AT91C_ID_TC1) | (1 << AT91C_ID_TC2); // Enable Clock to all timers | |
367 | AT91C_BASE_TCB->TCB_BMR = AT91C_TCB_TC0XC0S_TIOA1 // XC0 Clock = TIOA1 | |
368 | | AT91C_TCB_TC1XC1S_NONE // XC1 Clock = none | |
369 | | AT91C_TCB_TC2XC2S_TIOA0; // XC2 Clock = TIOA0 | |
370 | ||
371 | // configure TC1 to create a short pulse on TIOA1 when a rising edge on TIOB1 (= ssp_clk from FPGA) occurs: | |
372 | AT91C_BASE_TC1->TC_CCR = AT91C_TC_CLKDIS; // disable TC1 | |
373 | AT91C_BASE_TC1->TC_CMR = AT91C_TC_CLKS_TIMER_DIV1_CLOCK // TC1 Clock = MCK(48MHz)/2 = 24MHz | |
374 | | AT91C_TC_CPCSTOP // Stop clock on RC compare | |
375 | | AT91C_TC_EEVTEDG_RISING // Trigger on rising edge of Event | |
376 | | AT91C_TC_EEVT_TIOB // Event-Source: TIOB1 (= ssp_clk from FPGA = 13,56MHz/16) | |
377 | | AT91C_TC_ENETRG // Enable external trigger event | |
378 | | AT91C_TC_WAVESEL_UP // Upmode without automatic trigger on RC compare | |
379 | | AT91C_TC_WAVE // Waveform Mode | |
380 | | AT91C_TC_AEEVT_SET // Set TIOA1 on external event | |
381 | | AT91C_TC_ACPC_CLEAR; // Clear TIOA1 on RC Compare | |
382 | AT91C_BASE_TC1->TC_RC = 0x04; // RC Compare value = 0x04 | |
383 | ||
384 | // use TC0 to count TIOA1 pulses | |
385 | AT91C_BASE_TC0->TC_CCR = AT91C_TC_CLKDIS; // disable TC0 | |
386 | AT91C_BASE_TC0->TC_CMR = AT91C_TC_CLKS_XC0 // TC0 clock = XC0 clock = TIOA1 | |
387 | | AT91C_TC_WAVE // Waveform Mode | |
388 | | AT91C_TC_WAVESEL_UP // just count | |
389 | | AT91C_TC_ACPA_CLEAR // Clear TIOA0 on RA Compare | |
390 | | AT91C_TC_ACPC_SET; // Set TIOA0 on RC Compare | |
391 | AT91C_BASE_TC0->TC_RA = 1; // RA Compare value = 1; pulse width to TC2 | |
392 | AT91C_BASE_TC0->TC_RC = 0; // RC Compare value = 0; increment TC2 on overflow | |
393 | ||
394 | // use TC2 to count TIOA0 pulses (giving us a 32bit counter (TC0/TC2) clocked by ssp_clk) | |
395 | AT91C_BASE_TC2->TC_CCR = AT91C_TC_CLKDIS; // disable TC2 | |
396 | AT91C_BASE_TC2->TC_CMR = AT91C_TC_CLKS_XC2 // TC2 clock = XC2 clock = TIOA0 | |
397 | | AT91C_TC_WAVE // Waveform Mode | |
398 | | AT91C_TC_WAVESEL_UP; // just count | |
399 | ||
400 | AT91C_BASE_TC0->TC_CCR = AT91C_TC_CLKEN; // enable TC0 | |
401 | AT91C_BASE_TC1->TC_CCR = AT91C_TC_CLKEN; // enable TC1 | |
402 | AT91C_BASE_TC2->TC_CCR = AT91C_TC_CLKEN; // enable TC2 | |
403 | ||
404 | // | |
405 | // synchronize the counter with the ssp_frame signal. Note: FPGA must be in any iso14443 mode, otherwise SSC_FRAME and SSC_CLK signals would not be present | |
406 | // | |
407 | while(!(AT91C_BASE_PIOA->PIO_PDSR & GPIO_SSC_FRAME)); // wait for ssp_frame to go high (start of frame) | |
408 | while(AT91C_BASE_PIOA->PIO_PDSR & GPIO_SSC_FRAME); // wait for ssp_frame to be low | |
409 | while(!(AT91C_BASE_PIOA->PIO_PDSR & GPIO_SSC_CLK)); // wait for ssp_clk to go high | |
410 | // note: up to now two ssp_clk rising edges have passed since the rising edge of ssp_frame | |
411 | // it is now safe to assert a sync signal. This sets all timers to 0 on next active clock edge | |
412 | AT91C_BASE_TCB->TCB_BCR = 1; // assert Sync (set all timers to 0 on next active clock edge) | |
413 | // at the next (3rd) ssp_clk rising edge, TC1 will be reset (and not generate a clock signal to TC0) | |
414 | // at the next (4th) ssp_clk rising edge, TC0 (the low word of our counter) will be reset. From now on, | |
415 | // whenever the last three bits of our counter go 0, we can be sure to be in the middle of a frame transfer. | |
416 | // (just started with the transfer of the 4th Bit). | |
417 | // The high word of the counter (TC2) will not reset until the low word (TC0) overflows. Therefore need to wait quite some time before | |
418 | // we can use the counter. | |
419 | while (AT91C_BASE_TC0->TC_CV < 0xFFFF); | |
420 | // Note: needs one more SSP_CLK cycle (1.18 us) until TC2 resets. Don't call GetCountSspClk() that soon. | |
421 | } | |
422 | ||
423 | ||
424 | void ResetSspClk(void) { | |
425 | //enable clock of timer and software trigger | |
426 | AT91C_BASE_TC0->TC_CCR = AT91C_TC_CLKEN | AT91C_TC_SWTRG; | |
427 | AT91C_BASE_TC1->TC_CCR = AT91C_TC_CLKEN | AT91C_TC_SWTRG; | |
428 | AT91C_BASE_TC2->TC_CCR = AT91C_TC_CLKEN | AT91C_TC_SWTRG; | |
429 | while (AT91C_BASE_TC2->TC_CV > 0); | |
430 | } | |
431 | ||
432 | ||
433 | uint32_t RAMFUNC GetCountSspClk(){ | |
434 | uint32_t tmp_count; | |
435 | tmp_count = (AT91C_BASE_TC2->TC_CV << 16) | AT91C_BASE_TC0->TC_CV; | |
436 | if ((tmp_count & 0x0000ffff) == 0) { //small chance that we may have missed an increment in TC2 | |
437 | return (AT91C_BASE_TC2->TC_CV << 16); | |
438 | } | |
439 | else { | |
440 | return tmp_count; | |
441 | } | |
442 | } | |
443 | ||
444 | ||
445 | // ------------------------------------------------------------------------- | |
446 | // Timer for bitbanging, or LF stuff when you need a very precis timer | |
447 | // 1us = 1.5ticks | |
448 | // ------------------------------------------------------------------------- | |
449 | void StartTicks(void){ | |
450 | // initialization of the timer | |
451 | AT91C_BASE_PMC->PMC_PCER |= (1 << AT91C_ID_TC0) | (1 << AT91C_ID_TC1); | |
452 | AT91C_BASE_TCB->TCB_BMR = AT91C_TCB_TC0XC0S_NONE | AT91C_TCB_TC1XC1S_TIOA0 | AT91C_TCB_TC2XC2S_NONE; | |
453 | ||
454 | // disable TC0 and TC1 for re-configuration | |
455 | AT91C_BASE_TC0->TC_CCR = AT91C_TC_CLKDIS; | |
456 | AT91C_BASE_TC1->TC_CCR = AT91C_TC_CLKDIS; | |
457 | ||
458 | // first configure TC1 (higher, 0xFFFF0000) 16 bit counter | |
459 | AT91C_BASE_TC1->TC_CMR = AT91C_TC_CLKS_XC1; // just connect to TIOA0 from TC0 | |
460 | AT91C_BASE_TC1->TC_CCR = AT91C_TC_CLKEN | AT91C_TC_SWTRG; // re-enable timer and wait for TC0 | |
461 | ||
462 | // second configure TC0 (lower, 0x0000FFFF) 16 bit counter | |
463 | AT91C_BASE_TC0->TC_CMR = AT91C_TC_CLKS_TIMER_DIV3_CLOCK | // MCK(48MHz) / 32 | |
464 | AT91C_TC_WAVE | AT91C_TC_WAVESEL_UP_AUTO | | |
465 | AT91C_TC_ACPA_CLEAR | // RA comperator clears TIOA (carry bit) | |
466 | AT91C_TC_ACPC_SET | // RC comperator sets TIOA (carry bit) | |
467 | AT91C_TC_ASWTRG_SET; // SWTriger sets TIOA (carry bit) | |
468 | AT91C_BASE_TC0->TC_RC = 0; // set TIOA (carry bit) on overflow, return to zero | |
469 | AT91C_BASE_TC0->TC_RA = 1; // clear carry bit on next clock cycle | |
470 | AT91C_BASE_TC0->TC_CCR = AT91C_TC_CLKEN | AT91C_TC_SWTRG; // reset and re-enable timer | |
471 | ||
472 | // synchronized startup procedure | |
473 | while (AT91C_BASE_TC0->TC_CV > 0); // wait until TC0 returned to zero | |
474 | while (AT91C_BASE_TC0->TC_CV < 2); // and has started (TC_CV > TC_RA, now TC1 is cleared) | |
475 | ||
476 | // return to zero | |
477 | AT91C_BASE_TC1->TC_CCR = AT91C_TC_SWTRG; | |
478 | AT91C_BASE_TC0->TC_CCR = AT91C_TC_SWTRG; | |
479 | while (AT91C_BASE_TC0->TC_CV > 0); | |
480 | } | |
481 | ||
482 | ||
483 | uint32_t GetTicks(void) { | |
484 | uint32_t hi, lo; | |
485 | ||
486 | do { | |
487 | hi = AT91C_BASE_TC1->TC_CV; | |
488 | lo = AT91C_BASE_TC0->TC_CV; | |
489 | } while(hi != AT91C_BASE_TC1->TC_CV); | |
490 | ||
491 | return (hi << 16) | lo; | |
492 | } | |
493 | ||
494 | ||
495 | // Wait - Spindelay in ticks. | |
496 | // if called with a high number, this will trigger the WDT... | |
497 | void WaitTicks(uint32_t ticks){ | |
498 | if ( ticks == 0 ) return; | |
499 | ticks += GetTicks(); | |
500 | while (GetTicks() < ticks); | |
501 | } | |
502 | ||
503 | ||
504 | // Wait / Spindelay in us (microseconds) | |
505 | // 1us = 1.5ticks. | |
506 | void WaitUS(uint16_t us){ | |
507 | WaitTicks( (uint32_t)us * 3 / 2 ) ; | |
508 | } | |
509 | ||
510 | ||
511 | void WaitMS(uint16_t ms){ | |
512 | WaitTicks( (uint32_t)ms * 1500 ); | |
513 | } | |
514 | ||
515 | ||
516 | // Starts Clock and waits until its reset | |
517 | void ResetTicks(void){ | |
518 | AT91C_BASE_TC1->TC_CCR = AT91C_TC_CLKEN | AT91C_TC_SWTRG; | |
519 | AT91C_BASE_TC0->TC_CCR = AT91C_TC_CLKEN | AT91C_TC_SWTRG; | |
520 | while (AT91C_BASE_TC0->TC_CV > 0); | |
521 | } | |
522 | ||
523 | ||
524 | void ResetTimer(AT91PS_TC timer){ | |
525 | timer->TC_CCR = AT91C_TC_CLKEN | AT91C_TC_SWTRG; | |
526 | while(timer->TC_CV > 0) ; | |
527 | } | |
528 | ||
529 | ||
530 | // stop clock | |
531 | void StopTicks(void){ | |
532 | AT91C_BASE_TC0->TC_CCR = AT91C_TC_CLKDIS; | |
533 | AT91C_BASE_TC1->TC_CCR = AT91C_TC_CLKDIS; | |
534 | } | |
535 | ||
536 | ||
537 | static uint64_t next_random = 1; | |
538 | ||
539 | /* Generates a (non-cryptographically secure) 32-bit random number. | |
540 | * | |
541 | * We don't have an implementation of the "rand" function or a clock to seed it | |
542 | * with, so we just call GetTickCount the first time to seed ourselves. | |
543 | */ | |
544 | uint32_t prand() { | |
545 | if (next_random == 1) { | |
546 | next_random = GetTickCount(); | |
547 | } | |
548 | ||
549 | next_random = next_random * 6364136223846793005 + 1; | |
550 | return (uint32_t)(next_random >> 32) % 0xffffffff; | |
551 | } |