mips32, drop unnecessary code in mips32_pracc.c
[openocd.git] / src / target / mips32_pracc.c
blob69d9a0079ada108a6008c626a3b5ae159ef97cee
1 /***************************************************************************
2 * Copyright (C) 2008 by Spencer Oliver *
3 * spen@spen-soft.co.uk *
4 * *
5 * Copyright (C) 2008 by David T.L. Wong *
6 * *
7 * Copyright (C) 2009 by David N. Claffey <dnclaffey@gmail.com> *
8 * *
9 * Copyright (C) 2011 by Drasko DRASKOVIC *
10 * drasko.draskovic@gmail.com *
11 * *
12 * This program is free software; you can redistribute it and/or modify *
13 * it under the terms of the GNU General Public License as published by *
14 * the Free Software Foundation; either version 2 of the License, or *
15 * (at your option) any later version. *
16 * *
17 * This program is distributed in the hope that it will be useful, *
18 * but WITHOUT ANY WARRANTY; without even the implied warranty of *
19 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the *
20 * GNU General Public License for more details. *
21 * *
22 * You should have received a copy of the GNU General Public License *
23 * along with this program. If not, see <http://www.gnu.org/licenses/>. *
24 ***************************************************************************/
27 * This version has optimized assembly routines for 32 bit operations:
28 * - read word
29 * - write word
30 * - write array of words
32 * One thing to be aware of is that the MIPS32 cpu will execute the
33 * instruction after a branch instruction (one delay slot).
35 * For example:
36 * LW $2, ($5 +10)
37 * B foo
38 * LW $1, ($2 +100)
40 * The LW $1, ($2 +100) instruction is also executed. If this is
41 * not wanted a NOP can be inserted:
43 * LW $2, ($5 +10)
44 * B foo
45 * NOP
46 * LW $1, ($2 +100)
48 * or the code can be changed to:
50 * B foo
51 * LW $2, ($5 +10)
52 * LW $1, ($2 +100)
54 * The original code contained NOPs. I have removed these and moved
55 * the branches.
57 * These changes result in a 35% speed increase when programming an
58 * external flash.
60 * More improvement could be gained if the registers do no need
61 * to be preserved but in that case the routines should be aware
62 * OpenOCD is used as a flash programmer or as a debug tool.
64 * Nico Coesel
67 #ifdef HAVE_CONFIG_H
68 #include "config.h"
69 #endif
71 #include <helper/time_support.h>
73 #include "mips32.h"
74 #include "mips32_pracc.h"
76 static int wait_for_pracc_rw(struct mips_ejtag *ejtag_info, uint32_t *ctrl)
78 uint32_t ejtag_ctrl;
79 int64_t then = timeval_ms();
81 /* wait for the PrAcc to become "1" */
82 mips_ejtag_set_instr(ejtag_info, EJTAG_INST_CONTROL);
84 while (1) {
85 ejtag_ctrl = ejtag_info->ejtag_ctrl;
86 int retval = mips_ejtag_drscan_32(ejtag_info, &ejtag_ctrl);
87 if (retval != ERROR_OK)
88 return retval;
90 if (ejtag_ctrl & EJTAG_CTRL_PRACC)
91 break;
93 int64_t timeout = timeval_ms() - then;
94 if (timeout > 1000) {
95 LOG_DEBUG("DEBUGMODULE: No memory access in progress!");
96 return ERROR_JTAG_DEVICE_ERROR;
100 *ctrl = ejtag_ctrl;
101 return ERROR_OK;
104 /* Shift in control and address for a new processor access, save them in ejtag_info */
105 static int mips32_pracc_read_ctrl_addr(struct mips_ejtag *ejtag_info)
107 int retval = wait_for_pracc_rw(ejtag_info, &ejtag_info->pa_ctrl);
108 if (retval != ERROR_OK)
109 return retval;
111 mips_ejtag_set_instr(ejtag_info, EJTAG_INST_ADDRESS);
112 ejtag_info->pa_addr = 0;
113 retval = mips_ejtag_drscan_32(ejtag_info, &ejtag_info->pa_addr);
115 return retval;
118 /* Finish processor access */
119 static int mips32_pracc_finish(struct mips_ejtag *ejtag_info)
121 uint32_t ctrl = ejtag_info->ejtag_ctrl & ~EJTAG_CTRL_PRACC;
122 mips_ejtag_set_instr(ejtag_info, EJTAG_INST_CONTROL);
123 mips_ejtag_drscan_32_out(ejtag_info, ctrl);
125 return jtag_execute_queue();
128 int mips32_pracc_clean_text_jump(struct mips_ejtag *ejtag_info)
130 uint32_t jt_code = MIPS32_J((0x0FFFFFFF & MIPS32_PRACC_TEXT) >> 2);
131 int retval;
133 /* do 3 0/nops to clean pipeline before a jump to pracc text, NOP in delay slot */
134 for (int i = 0; i != 5; i++) {
135 /* Wait for pracc */
136 retval = wait_for_pracc_rw(ejtag_info, &ejtag_info->pa_ctrl);
137 if (retval != ERROR_OK)
138 return retval;
140 /* Data or instruction out */
141 mips_ejtag_set_instr(ejtag_info, EJTAG_INST_DATA);
142 uint32_t data = (i == 3) ? jt_code : MIPS32_NOP;
143 mips_ejtag_drscan_32_out(ejtag_info, data);
145 /* finish pa */
146 retval = mips32_pracc_finish(ejtag_info);
147 if (retval != ERROR_OK)
148 return retval;
151 if (ejtag_info->mode != 0) /* async mode support only for MIPS ... */
152 return ERROR_OK;
154 for (int i = 0; i != 2; i++) {
155 retval = mips32_pracc_read_ctrl_addr(ejtag_info);
156 if (retval != ERROR_OK)
157 return retval;
159 if (ejtag_info->pa_addr != MIPS32_PRACC_TEXT) { /* LEXRA/BMIPS ?, shift out another NOP, max 2 */
160 mips_ejtag_set_instr(ejtag_info, EJTAG_INST_DATA);
161 mips_ejtag_drscan_32_out(ejtag_info, MIPS32_NOP);
162 retval = mips32_pracc_finish(ejtag_info);
163 if (retval != ERROR_OK)
164 return retval;
165 } else
166 break;
169 return ERROR_OK;
172 int mips32_pracc_exec(struct mips_ejtag *ejtag_info, struct pracc_queue_info *ctx, uint32_t *param_out)
174 int code_count = 0;
175 int store_pending = 0; /* increases with every store instruction at dmseg, decreases with every store pa */
176 uint32_t max_store_addr = 0; /* for store pa address testing */
177 bool restart = 0; /* restarting control */
178 int restart_count = 0;
179 uint32_t instr = 0;
180 bool final_check = 0; /* set to 1 if in final checks after function code shifted out */
181 bool pass = 0; /* to check the pass through pracc text after function code sent */
182 int retval;
184 while (1) {
185 if (restart) {
186 if (restart_count < 3) { /* max 3 restarts allowed */
187 retval = mips32_pracc_clean_text_jump(ejtag_info);
188 if (retval != ERROR_OK)
189 return retval;
190 } else
191 return ERROR_JTAG_DEVICE_ERROR;
192 restart_count++;
193 restart = 0;
194 code_count = 0;
195 LOG_DEBUG("restarting code");
198 retval = mips32_pracc_read_ctrl_addr(ejtag_info); /* update current pa info: control and address */
199 if (retval != ERROR_OK)
200 return retval;
202 /* Check for read or write access */
203 if (ejtag_info->pa_ctrl & EJTAG_CTRL_PRNW) { /* write/store access */
204 /* Check for pending store from a previous store instruction at dmseg */
205 if (store_pending == 0) {
206 LOG_DEBUG("unexpected write at address %" PRIx32, ejtag_info->pa_addr);
207 if (code_count < 2) { /* allow for restart */
208 restart = 1;
209 continue;
210 } else
211 return ERROR_JTAG_DEVICE_ERROR;
212 } else {
213 /* check address */
214 if (ejtag_info->pa_addr < MIPS32_PRACC_PARAM_OUT || ejtag_info->pa_addr > max_store_addr) {
216 LOG_DEBUG("writing at unexpected address %" PRIx32, ejtag_info->pa_addr);
217 return ERROR_JTAG_DEVICE_ERROR;
220 /* read data */
221 uint32_t data = 0;
222 mips_ejtag_set_instr(ejtag_info, EJTAG_INST_DATA);
223 retval = mips_ejtag_drscan_32(ejtag_info, &data);
224 if (retval != ERROR_OK)
225 return retval;
227 /* store data at param out, address based offset */
228 param_out[(ejtag_info->pa_addr - MIPS32_PRACC_PARAM_OUT) / 4] = data;
229 store_pending--;
231 } else { /* read/fetch access */
232 if (!final_check) { /* executing function code */
233 /* check address */
234 if (ejtag_info->pa_addr != (MIPS32_PRACC_TEXT + code_count * 4)) {
235 LOG_DEBUG("reading at unexpected address %" PRIx32 ", expected %x",
236 ejtag_info->pa_addr, MIPS32_PRACC_TEXT + code_count * 4);
238 /* restart code execution only in some cases */
239 if (code_count == 1 && ejtag_info->pa_addr == MIPS32_PRACC_TEXT && restart_count == 0) {
240 LOG_DEBUG("restarting, without clean jump");
241 restart_count++;
242 code_count = 0;
243 continue;
244 } else if (code_count < 2) {
245 restart = 1;
246 continue;
249 return ERROR_JTAG_DEVICE_ERROR;
251 /* check for store instruction at dmseg */
252 uint32_t store_addr = ctx->pracc_list[ctx->max_code + code_count];
253 if (store_addr != 0) {
254 if (store_addr > max_store_addr)
255 max_store_addr = store_addr;
256 store_pending++;
259 instr = ctx->pracc_list[code_count++];
260 if (code_count == ctx->code_count) /* last instruction, start final check */
261 final_check = 1;
263 } else { /* final check after function code shifted out */
264 /* check address */
265 if (ejtag_info->pa_addr == MIPS32_PRACC_TEXT) {
266 if (!pass) { /* first pass through pracc text */
267 if (store_pending == 0) /* done, normal exit */
268 return ERROR_OK;
269 pass = 1; /* pracc text passed */
270 code_count = 0; /* restart code count */
271 } else {
272 LOG_DEBUG("unexpected second pass through pracc text");
273 return ERROR_JTAG_DEVICE_ERROR;
275 } else {
276 if (ejtag_info->pa_addr != (MIPS32_PRACC_TEXT + code_count * 4)) {
277 LOG_DEBUG("unexpected read address in final check: %" PRIx32 ", expected: %x",
278 ejtag_info->pa_addr, MIPS32_PRACC_TEXT + code_count * 4);
279 return ERROR_JTAG_DEVICE_ERROR;
282 if (!pass) {
283 if ((code_count - ctx->code_count) > 1) { /* allow max 2 instruction delay slot */
284 LOG_DEBUG("failed to jump back to pracc text");
285 return ERROR_JTAG_DEVICE_ERROR;
287 } else
288 if (code_count > 10) { /* enough, abandone */
289 LOG_DEBUG("execution abandoned, store pending: %d", store_pending);
290 return ERROR_JTAG_DEVICE_ERROR;
292 instr = MIPS32_NOP; /* shift out NOPs instructions */
293 code_count++;
296 /* Send instruction out */
297 mips_ejtag_set_instr(ejtag_info, EJTAG_INST_DATA);
298 mips_ejtag_drscan_32_out(ejtag_info, instr);
300 /* finish processor access, let the processor eat! */
301 retval = mips32_pracc_finish(ejtag_info);
302 if (retval != ERROR_OK)
303 return retval;
305 if (instr == MIPS32_DRET) /* after leaving debug mode nothing to do */
306 return ERROR_OK;
308 if (store_pending == 0 && pass) { /* store access done, but after passing pracc text */
309 LOG_DEBUG("warning: store access pass pracc text");
310 return ERROR_OK;
315 inline void pracc_queue_init(struct pracc_queue_info *ctx)
317 ctx->retval = ERROR_OK;
318 ctx->code_count = 0;
319 ctx->store_count = 0;
321 ctx->pracc_list = malloc(2 * ctx->max_code * sizeof(uint32_t));
322 if (ctx->pracc_list == NULL) {
323 LOG_ERROR("Out of memory");
324 ctx->retval = ERROR_FAIL;
328 inline void pracc_add(struct pracc_queue_info *ctx, uint32_t addr, uint32_t instr)
330 ctx->pracc_list[ctx->max_code + ctx->code_count] = addr;
331 ctx->pracc_list[ctx->code_count++] = instr;
332 if (addr)
333 ctx->store_count++;
336 inline void pracc_queue_free(struct pracc_queue_info *ctx)
338 if (ctx->code_count > ctx->max_code) /* Only for internal check, will be erased */
339 LOG_ERROR("Internal error, code count: %d > max code: %d", ctx->code_count, ctx->max_code);
340 if (ctx->pracc_list != NULL)
341 free(ctx->pracc_list);
344 int mips32_pracc_queue_exec(struct mips_ejtag *ejtag_info, struct pracc_queue_info *ctx, uint32_t *buf)
346 if (ejtag_info->mode == 0)
347 return mips32_pracc_exec(ejtag_info, ctx, buf);
349 union scan_in {
350 uint8_t scan_96[12];
351 struct {
352 uint8_t ctrl[4];
353 uint8_t data[4];
354 uint8_t addr[4];
355 } scan_32;
357 } *scan_in = malloc(sizeof(union scan_in) * (ctx->code_count + ctx->store_count));
358 if (scan_in == NULL) {
359 LOG_ERROR("Out of memory");
360 return ERROR_FAIL;
363 unsigned num_clocks =
364 ((uint64_t)(ejtag_info->scan_delay) * jtag_get_speed_khz() + 500000) / 1000000;
366 uint32_t ejtag_ctrl = ejtag_info->ejtag_ctrl & ~EJTAG_CTRL_PRACC;
367 mips_ejtag_set_instr(ejtag_info, EJTAG_INST_ALL);
369 int scan_count = 0;
370 for (int i = 0; i != 2 * ctx->code_count; i++) {
371 uint32_t data = 0;
372 if (i & 1u) { /* Check store address from previous instruction, if not the first */
373 if (i < 2 || 0 == ctx->pracc_list[ctx->max_code + (i / 2) - 1])
374 continue;
375 } else
376 data = ctx->pracc_list[i / 2];
378 jtag_add_clocks(num_clocks);
379 mips_ejtag_add_scan_96(ejtag_info, ejtag_ctrl, data, scan_in[scan_count++].scan_96);
382 int retval = jtag_execute_queue(); /* execute queued scans */
383 if (retval != ERROR_OK)
384 goto exit;
386 uint32_t fetch_addr = MIPS32_PRACC_TEXT; /* start address */
387 scan_count = 0;
388 for (int i = 0; i != 2 * ctx->code_count; i++) { /* verify every pracc access */
389 uint32_t store_addr = 0;
390 if (i & 1u) { /* Read store addres from previous instruction, if not the first */
391 store_addr = ctx->pracc_list[ctx->max_code + (i / 2) - 1];
392 if (i < 2 || 0 == store_addr)
393 continue;
396 ejtag_ctrl = buf_get_u32(scan_in[scan_count].scan_32.ctrl, 0, 32);
397 if (!(ejtag_ctrl & EJTAG_CTRL_PRACC)) {
398 LOG_ERROR("Error: access not pending count: %d", scan_count);
399 retval = ERROR_FAIL;
400 goto exit;
403 uint32_t addr = buf_get_u32(scan_in[scan_count].scan_32.addr, 0, 32);
405 if (store_addr != 0) {
406 if (!(ejtag_ctrl & EJTAG_CTRL_PRNW)) {
407 LOG_ERROR("Not a store/write access, count: %d", scan_count);
408 retval = ERROR_FAIL;
409 goto exit;
411 if (addr != store_addr) {
412 LOG_ERROR("Store address mismatch, read: %" PRIx32 " expected: %" PRIx32 " count: %d",
413 addr, store_addr, scan_count);
414 retval = ERROR_FAIL;
415 goto exit;
417 int buf_index = (addr - MIPS32_PRACC_PARAM_OUT) / 4;
418 buf[buf_index] = buf_get_u32(scan_in[scan_count].scan_32.data, 0, 32);
420 } else {
421 if (ejtag_ctrl & EJTAG_CTRL_PRNW) {
422 LOG_ERROR("Not a fetch/read access, count: %d", scan_count);
423 retval = ERROR_FAIL;
424 goto exit;
426 if (addr != fetch_addr) {
427 LOG_ERROR("Fetch addr mismatch, read: %" PRIx32 " expected: %" PRIx32 " count: %d",
428 addr, fetch_addr, scan_count);
429 retval = ERROR_FAIL;
430 goto exit;
432 fetch_addr += 4;
434 scan_count++;
436 exit:
437 free(scan_in);
438 return retval;
441 int mips32_pracc_read_u32(struct mips_ejtag *ejtag_info, uint32_t addr, uint32_t *buf)
443 struct pracc_queue_info ctx = {.max_code = 8};
444 pracc_queue_init(&ctx);
445 if (ctx.retval != ERROR_OK)
446 goto exit;
448 pracc_add(&ctx, 0, MIPS32_LUI(15, PRACC_UPPER_BASE_ADDR)); /* $15 = MIPS32_PRACC_BASE_ADDR */
449 pracc_add(&ctx, 0, MIPS32_LUI(8, UPPER16((addr + 0x8000)))); /* load $8 with modified upper address */
450 pracc_add(&ctx, 0, MIPS32_LW(8, LOWER16(addr), 8)); /* lw $8, LOWER16(addr)($8) */
451 pracc_add(&ctx, MIPS32_PRACC_PARAM_OUT,
452 MIPS32_SW(8, PRACC_OUT_OFFSET, 15)); /* sw $8,PRACC_OUT_OFFSET($15) */
453 pracc_add(&ctx, 0, MIPS32_LUI(8, UPPER16(ejtag_info->reg8))); /* restore upper 16 of $8 */
454 pracc_add(&ctx, 0, MIPS32_ORI(8, 8, LOWER16(ejtag_info->reg8))); /* restore lower 16 of $8 */
455 pracc_add(&ctx, 0, MIPS32_B(NEG16(ctx.code_count + 1))); /* jump to start */
456 pracc_add(&ctx, 0, MIPS32_MFC0(15, 31, 0)); /* move COP0 DeSave to $15 */
458 ctx.retval = mips32_pracc_queue_exec(ejtag_info, &ctx, buf);
459 exit:
460 pracc_queue_free(&ctx);
461 return ctx.retval;
464 int mips32_pracc_read_mem(struct mips_ejtag *ejtag_info, uint32_t addr, int size, int count, void *buf)
466 if (count == 1 && size == 4)
467 return mips32_pracc_read_u32(ejtag_info, addr, (uint32_t *)buf);
469 uint32_t *data = NULL;
470 struct pracc_queue_info ctx = {.max_code = 256 * 3 + 8 + 1}; /* alloc memory for the worst case */
471 pracc_queue_init(&ctx);
472 if (ctx.retval != ERROR_OK)
473 goto exit;
475 if (size != 4) {
476 data = malloc(256 * sizeof(uint32_t));
477 if (data == NULL) {
478 LOG_ERROR("Out of memory");
479 goto exit;
483 uint32_t *buf32 = buf;
484 uint16_t *buf16 = buf;
485 uint8_t *buf8 = buf;
487 while (count) {
488 ctx.code_count = 0;
489 ctx.store_count = 0;
490 int this_round_count = (count > 256) ? 256 : count;
491 uint32_t last_upper_base_addr = UPPER16((addr + 0x8000));
493 pracc_add(&ctx, 0, MIPS32_LUI(15, PRACC_UPPER_BASE_ADDR)); /* $15 = MIPS32_PRACC_BASE_ADDR */
494 pracc_add(&ctx, 0, MIPS32_LUI(9, last_upper_base_addr)); /* load the upper memory address in $9 */
496 for (int i = 0; i != this_round_count; i++) { /* Main code loop */
497 uint32_t upper_base_addr = UPPER16((addr + 0x8000));
498 if (last_upper_base_addr != upper_base_addr) { /* if needed, change upper address in $9 */
499 pracc_add(&ctx, 0, MIPS32_LUI(9, upper_base_addr));
500 last_upper_base_addr = upper_base_addr;
503 if (size == 4)
504 pracc_add(&ctx, 0, MIPS32_LW(8, LOWER16(addr), 9)); /* load from memory to $8 */
505 else if (size == 2)
506 pracc_add(&ctx, 0, MIPS32_LHU(8, LOWER16(addr), 9));
507 else
508 pracc_add(&ctx, 0, MIPS32_LBU(8, LOWER16(addr), 9));
510 pracc_add(&ctx, MIPS32_PRACC_PARAM_OUT + i * 4,
511 MIPS32_SW(8, PRACC_OUT_OFFSET + i * 4, 15)); /* store $8 at param out */
512 addr += size;
514 pracc_add(&ctx, 0, MIPS32_LUI(8, UPPER16(ejtag_info->reg8))); /* restore upper 16 bits of reg 8 */
515 pracc_add(&ctx, 0, MIPS32_ORI(8, 8, LOWER16(ejtag_info->reg8))); /* restore lower 16 bits of reg 8 */
516 pracc_add(&ctx, 0, MIPS32_LUI(9, UPPER16(ejtag_info->reg9))); /* restore upper 16 bits of reg 9 */
517 pracc_add(&ctx, 0, MIPS32_ORI(9, 9, LOWER16(ejtag_info->reg9))); /* restore lower 16 bits of reg 9 */
519 pracc_add(&ctx, 0, MIPS32_B(NEG16(ctx.code_count + 1))); /* jump to start */
520 pracc_add(&ctx, 0, MIPS32_MFC0(15, 31, 0)); /* restore $15 from DeSave */
522 if (size == 4) {
523 ctx.retval = mips32_pracc_queue_exec(ejtag_info, &ctx, buf32);
524 if (ctx.retval != ERROR_OK)
525 goto exit;
526 buf32 += this_round_count;
527 } else {
528 ctx.retval = mips32_pracc_queue_exec(ejtag_info, &ctx, data);
529 if (ctx.retval != ERROR_OK)
530 goto exit;
532 uint32_t *data_p = data;
533 for (int i = 0; i != this_round_count; i++) {
534 if (size == 2)
535 *buf16++ = *data_p++;
536 else
537 *buf8++ = *data_p++;
540 count -= this_round_count;
542 exit:
543 pracc_queue_free(&ctx);
544 if (data != NULL)
545 free(data);
546 return ctx.retval;
549 int mips32_cp0_read(struct mips_ejtag *ejtag_info, uint32_t *val, uint32_t cp0_reg, uint32_t cp0_sel)
551 struct pracc_queue_info ctx = {.max_code = 7};
552 pracc_queue_init(&ctx);
553 if (ctx.retval != ERROR_OK)
554 goto exit;
556 pracc_add(&ctx, 0, MIPS32_LUI(15, PRACC_UPPER_BASE_ADDR)); /* $15 = MIPS32_PRACC_BASE_ADDR */
557 pracc_add(&ctx, 0, MIPS32_MFC0(8, cp0_reg, cp0_sel)); /* move cp0 reg / sel to $8 */
558 pracc_add(&ctx, MIPS32_PRACC_PARAM_OUT,
559 MIPS32_SW(8, PRACC_OUT_OFFSET, 15)); /* store $8 to pracc_out */
560 pracc_add(&ctx, 0, MIPS32_MFC0(15, 31, 0)); /* restore $15 from DeSave */
561 pracc_add(&ctx, 0, MIPS32_LUI(8, UPPER16(ejtag_info->reg8))); /* restore upper 16 bits of $8 */
562 pracc_add(&ctx, 0, MIPS32_B(NEG16(ctx.code_count + 1))); /* jump to start */
563 pracc_add(&ctx, 0, MIPS32_ORI(8, 8, LOWER16(ejtag_info->reg8))); /* restore lower 16 bits of $8 */
565 ctx.retval = mips32_pracc_queue_exec(ejtag_info, &ctx, val);
566 exit:
567 pracc_queue_free(&ctx);
568 return ctx.retval;
571 int mips32_cp0_write(struct mips_ejtag *ejtag_info, uint32_t val, uint32_t cp0_reg, uint32_t cp0_sel)
573 struct pracc_queue_info ctx = {.max_code = 6};
574 pracc_queue_init(&ctx);
575 if (ctx.retval != ERROR_OK)
576 goto exit;
578 pracc_add(&ctx, 0, MIPS32_LUI(15, UPPER16(val))); /* Load val to $15 */
579 pracc_add(&ctx, 0, MIPS32_ORI(15, 15, LOWER16(val)));
581 pracc_add(&ctx, 0, MIPS32_MTC0(15, cp0_reg, cp0_sel)); /* write $15 to cp0 reg / sel */
583 pracc_add(&ctx, 0, MIPS32_B(NEG16(ctx.code_count + 1))); /* jump to start */
584 pracc_add(&ctx, 0, MIPS32_MFC0(15, 31, 0)); /* restore $15 from DeSave */
586 ctx.retval = mips32_pracc_queue_exec(ejtag_info, &ctx, NULL);
587 exit:
588 pracc_queue_free(&ctx);
589 return ctx.retval;
593 * \b mips32_pracc_sync_cache
595 * Synchronize Caches to Make Instruction Writes Effective
596 * (ref. doc. MIPS32 Architecture For Programmers Volume II: The MIPS32 Instruction Set,
597 * Document Number: MD00086, Revision 2.00, June 9, 2003)
599 * When the instruction stream is written, the SYNCI instruction should be used
600 * in conjunction with other instructions to make the newly-written instructions effective.
602 * Explanation :
603 * A program that loads another program into memory is actually writing the D- side cache.
604 * The instructions it has loaded can't be executed until they reach the I-cache.
606 * After the instructions have been written, the loader should arrange
607 * to write back any containing D-cache line and invalidate any locations
608 * already in the I-cache.
610 * If the cache coherency attribute (CCA) is set to zero, it's a write through cache, there is no need
611 * to write back.
613 * In the latest MIPS32/64 CPUs, MIPS provides the synci instruction,
614 * which does the whole job for a cache-line-sized chunk of the memory you just loaded:
615 * That is, it arranges a D-cache write-back (if CCA = 3) and an I-cache invalidate.
617 * The line size is obtained with the rdhwr SYNCI_Step in release 2 or from cp0 config 1 register in release 1.
619 static int mips32_pracc_synchronize_cache(struct mips_ejtag *ejtag_info,
620 uint32_t start_addr, uint32_t end_addr, int cached, int rel)
622 struct pracc_queue_info ctx = {.max_code = 256 * 2 + 5};
623 pracc_queue_init(&ctx);
624 if (ctx.retval != ERROR_OK)
625 goto exit;
626 /** Find cache line size in bytes */
627 uint32_t clsiz;
628 if (rel) { /* Release 2 (rel = 1) */
629 pracc_add(&ctx, 0, MIPS32_LUI(15, PRACC_UPPER_BASE_ADDR)); /* $15 = MIPS32_PRACC_BASE_ADDR */
631 pracc_add(&ctx, 0, MIPS32_RDHWR(8, MIPS32_SYNCI_STEP)); /* load synci_step value to $8 */
633 pracc_add(&ctx, MIPS32_PRACC_PARAM_OUT,
634 MIPS32_SW(8, PRACC_OUT_OFFSET, 15)); /* store $8 to pracc_out */
636 pracc_add(&ctx, 0, MIPS32_LUI(8, UPPER16(ejtag_info->reg8))); /* restore upper 16 bits of $8 */
637 pracc_add(&ctx, 0, MIPS32_ORI(8, 8, LOWER16(ejtag_info->reg8))); /* restore lower 16 bits of $8 */
638 pracc_add(&ctx, 0, MIPS32_B(NEG16(ctx.code_count + 1))); /* jump to start */
639 pracc_add(&ctx, 0, MIPS32_MFC0(15, 31, 0)); /* move COP0 DeSave to $15 */
641 ctx.retval = mips32_pracc_queue_exec(ejtag_info, &ctx, &clsiz);
642 if (ctx.retval != ERROR_OK)
643 goto exit;
645 } else { /* Release 1 (rel = 0) */
646 uint32_t conf;
647 ctx.retval = mips32_cp0_read(ejtag_info, &conf, 16, 1);
648 if (ctx.retval != ERROR_OK)
649 goto exit;
651 uint32_t dl = (conf & MIPS32_CONFIG1_DL_MASK) >> MIPS32_CONFIG1_DL_SHIFT;
653 /* dl encoding : dl=1 => 4 bytes, dl=2 => 8 bytes, etc... max dl=6 => 128 bytes cache line size */
654 clsiz = 0x2 << dl;
655 if (dl == 0)
656 clsiz = 0;
659 if (clsiz == 0)
660 goto exit; /* Nothing to do */
662 /* make sure clsiz is power of 2 */
663 if (clsiz & (clsiz - 1)) {
664 LOG_DEBUG("clsiz must be power of 2");
665 ctx.retval = ERROR_FAIL;
666 goto exit;
669 /* make sure start_addr and end_addr have the same offset inside de cache line */
670 start_addr |= clsiz - 1;
671 end_addr |= clsiz - 1;
673 ctx.code_count = 0;
674 int count = 0;
675 uint32_t last_upper_base_addr = UPPER16((start_addr + 0x8000));
677 pracc_add(&ctx, 0, MIPS32_LUI(15, last_upper_base_addr)); /* load upper memory base address to $15 */
679 while (start_addr <= end_addr) { /* main loop */
680 uint32_t upper_base_addr = UPPER16((start_addr + 0x8000));
681 if (last_upper_base_addr != upper_base_addr) { /* if needed, change upper address in $15 */
682 pracc_add(&ctx, 0, MIPS32_LUI(15, upper_base_addr));
683 last_upper_base_addr = upper_base_addr;
685 if (rel)
686 pracc_add(&ctx, 0, MIPS32_SYNCI(LOWER16(start_addr), 15)); /* synci instruction, offset($15) */
688 else {
689 if (cached == 3)
690 pracc_add(&ctx, 0, MIPS32_CACHE(MIPS32_CACHE_D_HIT_WRITEBACK,
691 LOWER16(start_addr), 15)); /* cache Hit_Writeback_D, offset($15) */
693 pracc_add(&ctx, 0, MIPS32_CACHE(MIPS32_CACHE_I_HIT_INVALIDATE,
694 LOWER16(start_addr), 15)); /* cache Hit_Invalidate_I, offset($15) */
696 start_addr += clsiz;
697 count++;
698 if (count == 256 && start_addr <= end_addr) { /* more ?, then execute code list */
699 pracc_add(&ctx, 0, MIPS32_B(NEG16(ctx.code_count + 1))); /* jump to start */
700 pracc_add(&ctx, 0, MIPS32_NOP); /* nop in delay slot */
702 ctx.retval = mips32_pracc_queue_exec(ejtag_info, &ctx, NULL);
703 if (ctx.retval != ERROR_OK)
704 goto exit;
706 ctx.code_count = 0;
707 count = 0;
710 pracc_add(&ctx, 0, MIPS32_SYNC);
711 pracc_add(&ctx, 0, MIPS32_B(NEG16(ctx.code_count + 1))); /* jump to start */
712 pracc_add(&ctx, 0, MIPS32_MFC0(15, 31, 0)); /* restore $15 from DeSave*/
714 ctx.retval = mips32_pracc_queue_exec(ejtag_info, &ctx, NULL);
715 exit:
716 pracc_queue_free(&ctx);
717 return ctx.retval;
720 static int mips32_pracc_write_mem_generic(struct mips_ejtag *ejtag_info,
721 uint32_t addr, int size, int count, const void *buf)
723 struct pracc_queue_info ctx = {.max_code = 128 * 3 + 5 + 1}; /* alloc memory for the worst case */
724 pracc_queue_init(&ctx);
725 if (ctx.retval != ERROR_OK)
726 goto exit;
728 const uint32_t *buf32 = buf;
729 const uint16_t *buf16 = buf;
730 const uint8_t *buf8 = buf;
732 while (count) {
733 ctx.code_count = 0;
734 ctx.store_count = 0;
735 int this_round_count = (count > 128) ? 128 : count;
736 uint32_t last_upper_base_addr = UPPER16((addr + 0x8000));
738 pracc_add(&ctx, 0, MIPS32_LUI(15, last_upper_base_addr)); /* load $15 with memory base address */
740 for (int i = 0; i != this_round_count; i++) {
741 uint32_t upper_base_addr = UPPER16((addr + 0x8000));
742 if (last_upper_base_addr != upper_base_addr) {
743 pracc_add(&ctx, 0, MIPS32_LUI(15, upper_base_addr)); /* if needed, change upper address in $15*/
744 last_upper_base_addr = upper_base_addr;
747 if (size == 4) { /* for word writes check if one half word is 0 and load it accordingly */
748 if (LOWER16(*buf32) == 0)
749 pracc_add(&ctx, 0, MIPS32_LUI(8, UPPER16(*buf32))); /* load only upper value */
750 else if (UPPER16(*buf32) == 0)
751 pracc_add(&ctx, 0, MIPS32_ORI(8, 0, LOWER16(*buf32))); /* load only lower */
752 else {
753 pracc_add(&ctx, 0, MIPS32_LUI(8, UPPER16(*buf32))); /* load upper and lower */
754 pracc_add(&ctx, 0, MIPS32_ORI(8, 8, LOWER16(*buf32)));
756 pracc_add(&ctx, 0, MIPS32_SW(8, LOWER16(addr), 15)); /* store word to memory */
757 buf32++;
759 } else if (size == 2) {
760 pracc_add(&ctx, 0, MIPS32_ORI(8, 0, *buf16)); /* load lower value */
761 pracc_add(&ctx, 0, MIPS32_SH(8, LOWER16(addr), 15)); /* store half word to memory */
762 buf16++;
764 } else {
765 pracc_add(&ctx, 0, MIPS32_ORI(8, 0, *buf8)); /* load lower value */
766 pracc_add(&ctx, 0, MIPS32_SB(8, LOWER16(addr), 15)); /* store byte to memory */
767 buf8++;
769 addr += size;
772 pracc_add(&ctx, 0, MIPS32_LUI(8, UPPER16(ejtag_info->reg8))); /* restore upper 16 bits of reg 8 */
773 pracc_add(&ctx, 0, MIPS32_ORI(8, 8, LOWER16(ejtag_info->reg8))); /* restore lower 16 bits of reg 8 */
775 pracc_add(&ctx, 0, MIPS32_B(NEG16(ctx.code_count + 1))); /* jump to start */
776 pracc_add(&ctx, 0, MIPS32_MFC0(15, 31, 0)); /* restore $15 from DeSave */
778 ctx.retval = mips32_pracc_queue_exec(ejtag_info, &ctx, NULL);
779 if (ctx.retval != ERROR_OK)
780 goto exit;
781 count -= this_round_count;
783 exit:
784 pracc_queue_free(&ctx);
785 return ctx.retval;
788 int mips32_pracc_write_mem(struct mips_ejtag *ejtag_info, uint32_t addr, int size, int count, const void *buf)
790 int retval = mips32_pracc_write_mem_generic(ejtag_info, addr, size, count, buf);
791 if (retval != ERROR_OK)
792 return retval;
795 * If we are in the cacheable region and cache is activated,
796 * we must clean D$ (if Cache Coherency Attribute is set to 3) + invalidate I$ after we did the write,
797 * so that changes do not continue to live only in D$ (if CCA = 3), but to be
798 * replicated in I$ also (maybe we wrote the istructions)
800 uint32_t conf = 0;
801 int cached = 0;
803 if ((KSEGX(addr) == KSEG1) || ((addr >= 0xff200000) && (addr <= 0xff3fffff)))
804 return retval; /*Nothing to do*/
806 mips32_cp0_read(ejtag_info, &conf, 16, 0);
808 switch (KSEGX(addr)) {
809 case KUSEG:
810 cached = (conf & MIPS32_CONFIG0_KU_MASK) >> MIPS32_CONFIG0_KU_SHIFT;
811 break;
812 case KSEG0:
813 cached = (conf & MIPS32_CONFIG0_K0_MASK) >> MIPS32_CONFIG0_K0_SHIFT;
814 break;
815 case KSEG2:
816 case KSEG3:
817 cached = (conf & MIPS32_CONFIG0_K23_MASK) >> MIPS32_CONFIG0_K23_SHIFT;
818 break;
819 default:
820 /* what ? */
821 break;
825 * Check cachablitiy bits coherency algorithm
826 * is the region cacheable or uncached.
827 * If cacheable we have to synchronize the cache
829 if (cached == 3 || cached == 0) { /* Write back cache or write through cache */
830 uint32_t start_addr = addr;
831 uint32_t end_addr = addr + count * size;
832 uint32_t rel = (conf & MIPS32_CONFIG0_AR_MASK) >> MIPS32_CONFIG0_AR_SHIFT;
833 if (rel > 1) {
834 LOG_DEBUG("Unknown release in cache code");
835 return ERROR_FAIL;
837 retval = mips32_pracc_synchronize_cache(ejtag_info, start_addr, end_addr, cached, rel);
840 return retval;
843 int mips32_pracc_write_regs(struct mips_ejtag *ejtag_info, uint32_t *regs)
845 static const uint32_t cp0_write_code[] = {
846 MIPS32_MTC0(1, 12, 0), /* move $1 to status */
847 MIPS32_MTLO(1), /* move $1 to lo */
848 MIPS32_MTHI(1), /* move $1 to hi */
849 MIPS32_MTC0(1, 8, 0), /* move $1 to badvaddr */
850 MIPS32_MTC0(1, 13, 0), /* move $1 to cause*/
851 MIPS32_MTC0(1, 24, 0), /* move $1 to depc (pc) */
854 struct pracc_queue_info ctx = {.max_code = 37 * 2 + 7 + 1};
855 pracc_queue_init(&ctx);
856 if (ctx.retval != ERROR_OK)
857 goto exit;
859 /* load registers 2 to 31 with lui and ori instructions, check if some instructions can be saved */
860 for (int i = 2; i < 32; i++) {
861 if (LOWER16((regs[i])) == 0) /* if lower half word is 0, lui instruction only */
862 pracc_add(&ctx, 0, MIPS32_LUI(i, UPPER16((regs[i]))));
863 else if (UPPER16((regs[i])) == 0) /* if upper half word is 0, ori with $0 only*/
864 pracc_add(&ctx, 0, MIPS32_ORI(i, 0, LOWER16((regs[i]))));
865 else { /* default, load with lui and ori instructions */
866 pracc_add(&ctx, 0, MIPS32_LUI(i, UPPER16((regs[i]))));
867 pracc_add(&ctx, 0, MIPS32_ORI(i, i, LOWER16((regs[i]))));
871 for (int i = 0; i != 6; i++) {
872 pracc_add(&ctx, 0, MIPS32_LUI(1, UPPER16((regs[i + 32])))); /* load CPO value in $1, with lui and ori */
873 pracc_add(&ctx, 0, MIPS32_ORI(1, 1, LOWER16((regs[i + 32]))));
874 pracc_add(&ctx, 0, cp0_write_code[i]); /* write value from $1 to CPO register */
876 pracc_add(&ctx, 0, MIPS32_MTC0(15, 31, 0)); /* load $15 in DeSave */
877 pracc_add(&ctx, 0, MIPS32_LUI(1, UPPER16((regs[1])))); /* load upper half word in $1 */
878 pracc_add(&ctx, 0, MIPS32_B(NEG16(ctx.code_count + 1))); /* jump to start */
879 pracc_add(&ctx, 0, MIPS32_ORI(1, 1, LOWER16((regs[1])))); /* load lower half word in $1 */
881 ctx.retval = mips32_pracc_queue_exec(ejtag_info, &ctx, NULL);
883 ejtag_info->reg8 = regs[8];
884 ejtag_info->reg9 = regs[9];
885 exit:
886 pracc_queue_free(&ctx);
887 return ctx.retval;
890 int mips32_pracc_read_regs(struct mips_ejtag *ejtag_info, uint32_t *regs)
892 static int cp0_read_code[] = {
893 MIPS32_MFC0(8, 12, 0), /* move status to $8 */
894 MIPS32_MFLO(8), /* move lo to $8 */
895 MIPS32_MFHI(8), /* move hi to $8 */
896 MIPS32_MFC0(8, 8, 0), /* move badvaddr to $8 */
897 MIPS32_MFC0(8, 13, 0), /* move cause to $8 */
898 MIPS32_MFC0(8, 24, 0), /* move depc (pc) to $8 */
901 struct pracc_queue_info ctx = {.max_code = 49};
902 pracc_queue_init(&ctx);
903 if (ctx.retval != ERROR_OK)
904 goto exit;
906 pracc_add(&ctx, 0, MIPS32_MTC0(1, 31, 0)); /* move $1 to COP0 DeSave */
907 pracc_add(&ctx, 0, MIPS32_LUI(1, PRACC_UPPER_BASE_ADDR)); /* $1 = MIP32_PRACC_BASE_ADDR */
909 for (int i = 2; i != 32; i++) /* store GPR's 2 to 31 */
910 pracc_add(&ctx, MIPS32_PRACC_PARAM_OUT + (i * 4),
911 MIPS32_SW(i, PRACC_OUT_OFFSET + (i * 4), 1));
913 for (int i = 0; i != 6; i++) {
914 pracc_add(&ctx, 0, cp0_read_code[i]); /* load COP0 needed registers to $8 */
915 pracc_add(&ctx, MIPS32_PRACC_PARAM_OUT + (i + 32) * 4, /* store $8 at PARAM OUT */
916 MIPS32_SW(8, PRACC_OUT_OFFSET + (i + 32) * 4, 1));
918 pracc_add(&ctx, 0, MIPS32_MFC0(8, 31, 0)); /* move DeSave to $8, reg1 value */
919 pracc_add(&ctx, MIPS32_PRACC_PARAM_OUT + 4, /* store reg1 value from $8 to param out */
920 MIPS32_SW(8, PRACC_OUT_OFFSET + 4, 1));
922 pracc_add(&ctx, 0, MIPS32_MFC0(1, 31, 0)); /* move COP0 DeSave to $1, restore reg1 */
923 pracc_add(&ctx, 0, MIPS32_B(NEG16(ctx.code_count + 1))); /* jump to start */
924 pracc_add(&ctx, 0, MIPS32_MTC0(15, 31, 0)); /* load $15 in DeSave */
926 ctx.retval = mips32_pracc_queue_exec(ejtag_info, &ctx, regs);
928 ejtag_info->reg8 = regs[8]; /* reg8 is saved but not restored, next called function should restore it */
929 ejtag_info->reg9 = regs[9];
930 exit:
931 pracc_queue_free(&ctx);
932 return ctx.retval;
935 /* fastdata upload/download requires an initialized working area
936 * to load the download code; it should not be called otherwise
937 * fetch order from the fastdata area
938 * 1. start addr
939 * 2. end addr
940 * 3. data ...
942 int mips32_pracc_fastdata_xfer(struct mips_ejtag *ejtag_info, struct working_area *source,
943 int write_t, uint32_t addr, int count, uint32_t *buf)
945 uint32_t handler_code[] = {
946 /* caution when editing, table is modified below */
947 /* r15 points to the start of this code */
948 MIPS32_SW(8, MIPS32_FASTDATA_HANDLER_SIZE - 4, 15),
949 MIPS32_SW(9, MIPS32_FASTDATA_HANDLER_SIZE - 8, 15),
950 MIPS32_SW(10, MIPS32_FASTDATA_HANDLER_SIZE - 12, 15),
951 MIPS32_SW(11, MIPS32_FASTDATA_HANDLER_SIZE - 16, 15),
952 /* start of fastdata area in t0 */
953 MIPS32_LUI(8, UPPER16(MIPS32_PRACC_FASTDATA_AREA)),
954 MIPS32_ORI(8, 8, LOWER16(MIPS32_PRACC_FASTDATA_AREA)),
955 MIPS32_LW(9, 0, 8), /* start addr in t1 */
956 MIPS32_LW(10, 0, 8), /* end addr to t2 */
957 /* loop: */
958 /* 8 */ MIPS32_LW(11, 0, 0), /* lw t3,[t8 | r9] */
959 /* 9 */ MIPS32_SW(11, 0, 0), /* sw t3,[r9 | r8] */
960 MIPS32_BNE(10, 9, NEG16(3)), /* bne $t2,t1,loop */
961 MIPS32_ADDI(9, 9, 4), /* addi t1,t1,4 */
963 MIPS32_LW(8, MIPS32_FASTDATA_HANDLER_SIZE - 4, 15),
964 MIPS32_LW(9, MIPS32_FASTDATA_HANDLER_SIZE - 8, 15),
965 MIPS32_LW(10, MIPS32_FASTDATA_HANDLER_SIZE - 12, 15),
966 MIPS32_LW(11, MIPS32_FASTDATA_HANDLER_SIZE - 16, 15),
968 MIPS32_LUI(15, UPPER16(MIPS32_PRACC_TEXT)),
969 MIPS32_ORI(15, 15, LOWER16(MIPS32_PRACC_TEXT)),
970 MIPS32_JR(15), /* jr start */
971 MIPS32_MFC0(15, 31, 0), /* move COP0 DeSave to $15 */
974 uint32_t jmp_code[] = {
975 /* 0 */ MIPS32_LUI(15, 0), /* addr of working area added below */
976 /* 1 */ MIPS32_ORI(15, 15, 0), /* addr of working area added below */
977 MIPS32_JR(15), /* jump to ram program */
978 MIPS32_NOP,
981 int retval, i;
982 uint32_t val, ejtag_ctrl;
984 if (source->size < MIPS32_FASTDATA_HANDLER_SIZE)
985 return ERROR_TARGET_RESOURCE_NOT_AVAILABLE;
987 if (write_t) {
988 handler_code[8] = MIPS32_LW(11, 0, 8); /* load data from probe at fastdata area */
989 handler_code[9] = MIPS32_SW(11, 0, 9); /* store data to RAM @ r9 */
990 } else {
991 handler_code[8] = MIPS32_LW(11, 0, 9); /* load data from RAM @ r9 */
992 handler_code[9] = MIPS32_SW(11, 0, 8); /* store data to probe at fastdata area */
995 /* write program into RAM */
996 if (write_t != ejtag_info->fast_access_save) {
997 mips32_pracc_write_mem(ejtag_info, source->address, 4, ARRAY_SIZE(handler_code), handler_code);
998 /* save previous operation to speed to any consecutive read/writes */
999 ejtag_info->fast_access_save = write_t;
1002 LOG_DEBUG("%s using 0x%.8" TARGET_PRIxADDR " for write handler", __func__, source->address);
1004 jmp_code[0] |= UPPER16(source->address);
1005 jmp_code[1] |= LOWER16(source->address);
1007 for (i = 0; i < (int) ARRAY_SIZE(jmp_code); i++) {
1008 retval = wait_for_pracc_rw(ejtag_info, &ejtag_ctrl);
1009 if (retval != ERROR_OK)
1010 return retval;
1012 mips_ejtag_set_instr(ejtag_info, EJTAG_INST_DATA);
1013 mips_ejtag_drscan_32_out(ejtag_info, jmp_code[i]);
1015 /* Clear the access pending bit (let the processor eat!) */
1016 ejtag_ctrl = ejtag_info->ejtag_ctrl & ~EJTAG_CTRL_PRACC;
1017 mips_ejtag_set_instr(ejtag_info, EJTAG_INST_CONTROL);
1018 mips_ejtag_drscan_32_out(ejtag_info, ejtag_ctrl);
1021 /* wait PrAcc pending bit for FASTDATA write, read address */
1022 retval = mips32_pracc_read_ctrl_addr(ejtag_info);
1023 if (retval != ERROR_OK)
1024 return retval;
1026 /* next fetch to dmseg should be in FASTDATA_AREA, check */
1027 if (ejtag_info->pa_addr != MIPS32_PRACC_FASTDATA_AREA)
1028 return ERROR_FAIL;
1030 /* Send the load start address */
1031 val = addr;
1032 mips_ejtag_set_instr(ejtag_info, EJTAG_INST_FASTDATA);
1033 mips_ejtag_fastdata_scan(ejtag_info, 1, &val);
1035 retval = wait_for_pracc_rw(ejtag_info, &ejtag_ctrl);
1036 if (retval != ERROR_OK)
1037 return retval;
1039 /* Send the load end address */
1040 val = addr + (count - 1) * 4;
1041 mips_ejtag_set_instr(ejtag_info, EJTAG_INST_FASTDATA);
1042 mips_ejtag_fastdata_scan(ejtag_info, 1, &val);
1044 unsigned num_clocks = 0; /* like in legacy code */
1045 if (ejtag_info->mode != 0)
1046 num_clocks = ((uint64_t)(ejtag_info->scan_delay) * jtag_get_speed_khz() + 500000) / 1000000;
1048 for (i = 0; i < count; i++) {
1049 jtag_add_clocks(num_clocks);
1050 retval = mips_ejtag_fastdata_scan(ejtag_info, write_t, buf++);
1051 if (retval != ERROR_OK)
1052 return retval;
1055 retval = jtag_execute_queue();
1056 if (retval != ERROR_OK) {
1057 LOG_ERROR("fastdata load failed");
1058 return retval;
1061 retval = mips32_pracc_read_ctrl_addr(ejtag_info);
1062 if (retval != ERROR_OK)
1063 return retval;
1065 if (ejtag_info->pa_addr != MIPS32_PRACC_TEXT)
1066 LOG_ERROR("mini program did not return to start");
1068 return retval;