1 // SPDX-License-Identifier: GPL-2.0+
3 * Chromium OS cros_ec driver - sandbox emulation
5 * Copyright (c) 2013 The Chromium OS Authors.
11 #include <ec_commands.h>
16 #include <u-boot/sha256.h>
18 #include <asm/malloc.h>
19 #include <asm/state.h>
22 #include <linux/input.h>
25 * Ultimately it shold be possible to connect an Chrome OS EC emulation
26 * to U-Boot and remove all of this code. But this provides a test
27 * environment for bringing up chromeos_sandbox and demonstrating its
30 * This emulation includes the following:
32 * 1. Emulation of the keyboard, by converting keypresses received from SDL
33 * into key scan data, passed back from the EC as key scan messages. The
34 * key layout is read from the device tree.
36 * 2. Emulation of vboot context - so this can be read/written as required.
38 * 3. Save/restore of EC state, so that the vboot context, flash memory
39 * contents and current image can be preserved across boots. This is important
40 * since the EC is supposed to continue running even if the AP resets.
42 * 4. Some event support, in particular allowing Escape to be pressed on boot
43 * to enter recovery mode. The EC passes this to U-Boot through the normal
46 * 5. Flash read/write/erase support, so that software sync works. The
47 * protect messages are supported but no protection is implemented.
49 * 6. Hashing of the EC image, again to support software sync.
51 * Other features can be added, although a better path is probably to link
52 * the EC image in with U-Boot (Vic has demonstrated a prototype for this).
55 #define KEYBOARD_ROWS 8
56 #define KEYBOARD_COLS 13
58 /* A single entry of the key matrix */
59 struct ec_keymatrix_entry {
60 int row; /* key matrix row */
61 int col; /* key matrix column */
62 int keycode; /* corresponding linux key code */
66 * struct ec_state - Information about the EC state
68 * @vbnv_context: Vboot context data stored by EC
69 * @ec_config: FDT config information about the EC (e.g. flashmap)
70 * @flash_data: Contents of flash memory
71 * @flash_data_len: Size of flash memory
72 * @current_image: Current image the EC is running
73 * @matrix_count: Number of keys to decode in matrix
74 * @matrix: Information about keyboard matrix
75 * @keyscan: Current keyscan information (bit set for each row/column pressed)
76 * @recovery_req: Keyboard recovery requested
77 * @test_flags: Flags that control behaviour for tests
80 u8 vbnv_context[EC_VBNV_BLOCK_SIZE_V2];
81 struct fdt_cros_ec ec_config;
84 enum ec_current_image current_image;
86 struct ec_keymatrix_entry *matrix; /* the key matrix info */
87 uint8_t keyscan[KEYBOARD_COLS];
93 * cros_ec_read_state() - read the sandbox EC state from the state file
95 * If data is available, then blob and node will provide access to it. If
96 * not this function sets up an empty EC.
98 * @param blob: Pointer to device tree blob, or NULL if no data to read
99 * @param node: Node offset to read from
101 static int cros_ec_read_state(const void *blob, int node)
103 struct ec_state *ec = &s_state;
107 /* Set everything to defaults */
108 ec->current_image = EC_IMAGE_RO;
112 /* Read the data if available */
113 ec->current_image = fdtdec_get_int(blob, node, "current-image",
115 prop = fdt_getprop(blob, node, "vbnv-context", &len);
116 if (prop && len == sizeof(ec->vbnv_context))
117 memcpy(ec->vbnv_context, prop, len);
119 prop = fdt_getprop(blob, node, "flash-data", &len);
121 ec->flash_data_len = len;
122 ec->flash_data = malloc(len);
125 memcpy(ec->flash_data, prop, len);
126 debug("%s: Loaded EC flash data size %#x\n", __func__, len);
133 * cros_ec_write_state() - Write out our state to the state file
135 * The caller will ensure that there is a node ready for the state. The node
136 * may already contain the old state, in which case it is overridden.
138 * @param blob: Device tree blob holding state
139 * @param node: Node to write our state into
141 static int cros_ec_write_state(void *blob, int node)
143 struct ec_state *ec = g_state;
145 /* We are guaranteed enough space to write basic properties */
146 fdt_setprop_u32(blob, node, "current-image", ec->current_image);
147 fdt_setprop(blob, node, "vbnv-context", ec->vbnv_context,
148 sizeof(ec->vbnv_context));
149 return state_setprop(node, "flash-data", ec->flash_data,
150 ec->ec_config.flash.length);
153 SANDBOX_STATE_IO(cros_ec, "google,cros-ec", cros_ec_read_state,
154 cros_ec_write_state);
157 * Return the number of bytes used in the specified image.
159 * This is the actual size of code+data in the image, as opposed to the
160 * amount of space reserved in flash for that image. This code is similar to
161 * that used by the real EC code base.
163 * @param ec Current emulated EC state
164 * @param entry Flash map entry containing the image to check
165 * @return actual image size in bytes, 0 if the image contains no content or
168 static int get_image_used(struct ec_state *ec, struct fmap_entry *entry)
173 * Scan backwards looking for 0xea byte, which is by definition the
174 * last byte of the image. See ec.lds.S for how this is inserted at
175 * the end of the image.
177 for (size = entry->length - 1;
178 size > 0 && ec->flash_data[entry->offset + size] != 0xea;
182 return size ? size + 1 : 0; /* 0xea byte IS part of the image */
186 * Read the key matrix from the device tree
188 * Keymap entries in the fdt take the form of 0xRRCCKKKK where
189 * RR=Row CC=Column KKKK=Key Code
191 * @param ec Current emulated EC state
192 * @param node Keyboard node of device tree containing keyscan information
193 * @return 0 if ok, -1 on error
195 static int keyscan_read_fdt_matrix(struct ec_state *ec, ofnode node)
201 cell = ofnode_get_property(node, "linux,keymap", &len);
202 ec->matrix_count = len / 4;
203 ec->matrix = calloc(ec->matrix_count, sizeof(*ec->matrix));
205 debug("%s: Out of memory for key matrix\n", __func__);
209 /* Now read the data */
210 for (upto = 0; upto < ec->matrix_count; upto++) {
211 struct ec_keymatrix_entry *matrix = &ec->matrix[upto];
214 word = fdt32_to_cpu(*cell++);
215 matrix->row = word >> 24;
216 matrix->col = (word >> 16) & 0xff;
217 matrix->keycode = word & 0xffff;
219 /* Hard-code some sanity limits for now */
220 if (matrix->row >= KEYBOARD_ROWS ||
221 matrix->col >= KEYBOARD_COLS) {
222 debug("%s: Matrix pos out of range (%d,%d)\n",
223 __func__, matrix->row, matrix->col);
228 if (upto != ec->matrix_count) {
229 debug("%s: Read mismatch from key matrix\n", __func__);
237 * Return the next keyscan message contents
239 * @param ec Current emulated EC state
240 * @param scan Place to put keyscan bytes for the keyscan message (must hold
241 * enough space for a full keyscan)
242 * @return number of bytes of valid scan data
244 static int cros_ec_keyscan(struct ec_state *ec, uint8_t *scan)
246 const struct ec_keymatrix_entry *matrix;
247 int bytes = KEYBOARD_COLS;
248 int key[8]; /* allow up to 8 keys to be pressed at once */
252 memset(ec->keyscan, '\0', bytes);
253 count = sandbox_sdl_scan_keys(key, ARRAY_SIZE(key));
255 /* Look up keycode in matrix */
256 for (i = 0, matrix = ec->matrix; i < ec->matrix_count; i++, matrix++) {
260 for (found = false, j = 0; j < count; j++) {
261 if (matrix->keycode == key[j])
266 debug("%d: %d,%d\n", matrix->keycode, matrix->row,
268 ec->keyscan[matrix->col] |= 1 << matrix->row;
272 memcpy(scan, ec->keyscan, bytes);
277 * Process an emulated EC command
279 * @param ec Current emulated EC state
280 * @param req_hdr Pointer to request header
281 * @param req_data Pointer to body of request
282 * @param resp_hdr Pointer to place to put response header
283 * @param resp_data Pointer to place to put response data, if any
284 * @return length of response data, or 0 for no response data, or -1 on error
286 static int process_cmd(struct ec_state *ec,
287 struct ec_host_request *req_hdr, const void *req_data,
288 struct ec_host_response *resp_hdr, void *resp_data)
292 /* TODO(sjg@chromium.org): Check checksums */
293 debug("EC command %#0x\n", req_hdr->command);
295 switch (req_hdr->command) {
297 const struct ec_params_hello *req = req_data;
298 struct ec_response_hello *resp = resp_data;
300 resp->out_data = req->in_data + 0x01020304;
301 if (ec->test_flags & CROSECT_BREAK_HELLO)
306 case EC_CMD_GET_VERSION: {
307 struct ec_response_get_version *resp = resp_data;
309 strcpy(resp->version_string_ro, "sandbox_ro");
310 strcpy(resp->version_string_rw, "sandbox_rw");
311 resp->current_image = ec->current_image;
312 debug("Current image %d\n", resp->current_image);
316 case EC_CMD_VBNV_CONTEXT: {
317 const struct ec_params_vbnvcontext *req = req_data;
318 struct ec_response_vbnvcontext *resp = resp_data;
321 case EC_VBNV_CONTEXT_OP_READ:
322 /* TODO(sjg@chromium.org): Support full-size context */
323 memcpy(resp->block, ec->vbnv_context,
327 case EC_VBNV_CONTEXT_OP_WRITE:
328 /* TODO(sjg@chromium.org): Support full-size context */
329 memcpy(ec->vbnv_context, req->block,
334 printf(" ** Unknown vbnv_context command %#02x\n",
340 case EC_CMD_REBOOT_EC: {
341 const struct ec_params_reboot_ec *req = req_data;
343 printf("Request reboot type %d\n", req->cmd);
345 case EC_REBOOT_DISABLE_JUMP:
348 case EC_REBOOT_JUMP_RW:
349 ec->current_image = EC_IMAGE_RW;
353 puts(" ** Unknown type");
358 case EC_CMD_HOST_EVENT_GET_B: {
359 struct ec_response_host_event_mask *resp = resp_data;
362 if (ec->recovery_req) {
363 resp->mask |= EC_HOST_EVENT_MASK(
364 EC_HOST_EVENT_KEYBOARD_RECOVERY);
370 case EC_CMD_VBOOT_HASH: {
371 const struct ec_params_vboot_hash *req = req_data;
372 struct ec_response_vboot_hash *resp = resp_data;
373 struct fmap_entry *entry;
376 entry = &ec->ec_config.region[EC_FLASH_REGION_ACTIVE];
379 case EC_VBOOT_HASH_RECALC:
380 case EC_VBOOT_HASH_GET:
381 size = SHA256_SUM_LEN;
382 len = get_image_used(ec, entry);
383 ret = hash_block("sha256",
384 ec->flash_data + entry->offset,
385 len, resp->hash_digest, &size);
387 printf(" ** hash_block() failed\n");
390 resp->status = EC_VBOOT_HASH_STATUS_DONE;
391 resp->hash_type = EC_VBOOT_HASH_TYPE_SHA256;
392 resp->digest_size = size;
394 resp->offset = entry->offset;
399 printf(" ** EC_CMD_VBOOT_HASH: Unknown command %d\n",
405 case EC_CMD_FLASH_PROTECT: {
406 const struct ec_params_flash_protect *req = req_data;
407 struct ec_response_flash_protect *resp = resp_data;
408 uint32_t expect = EC_FLASH_PROTECT_ALL_NOW |
409 EC_FLASH_PROTECT_ALL_AT_BOOT;
411 printf("mask=%#x, flags=%#x\n", req->mask, req->flags);
412 if (req->flags == expect || req->flags == 0) {
413 resp->flags = req->flags ? EC_FLASH_PROTECT_ALL_NOW :
415 resp->valid_flags = EC_FLASH_PROTECT_ALL_NOW;
416 resp->writable_flags = 0;
419 puts(" ** unexpected flash protect request\n");
424 case EC_CMD_FLASH_REGION_INFO: {
425 const struct ec_params_flash_region_info *req = req_data;
426 struct ec_response_flash_region_info *resp = resp_data;
427 struct fmap_entry *entry;
429 switch (req->region) {
430 case EC_FLASH_REGION_RO:
431 case EC_FLASH_REGION_ACTIVE:
432 case EC_FLASH_REGION_WP_RO:
433 entry = &ec->ec_config.region[req->region];
434 resp->offset = entry->offset;
435 resp->size = entry->length;
437 printf("EC flash region %d: offset=%#x, size=%#x\n",
438 req->region, resp->offset, resp->size);
441 printf("** Unknown flash region %d\n", req->region);
446 case EC_CMD_FLASH_ERASE: {
447 const struct ec_params_flash_erase *req = req_data;
449 memset(ec->flash_data + req->offset,
450 ec->ec_config.flash_erase_value,
455 case EC_CMD_FLASH_WRITE: {
456 const struct ec_params_flash_write *req = req_data;
458 memcpy(ec->flash_data + req->offset, req + 1, req->size);
462 case EC_CMD_MKBP_STATE:
463 len = cros_ec_keyscan(ec, resp_data);
465 case EC_CMD_ENTERING_MODE:
468 case EC_CMD_GET_NEXT_EVENT: {
469 struct ec_response_get_next_event *resp = resp_data;
471 resp->event_type = EC_MKBP_EVENT_KEY_MATRIX;
472 cros_ec_keyscan(ec, resp->data.key_matrix);
477 printf(" ** Unknown EC command %#02x\n", req_hdr->command);
484 int cros_ec_sandbox_packet(struct udevice *udev, int out_bytes, int in_bytes)
486 struct cros_ec_dev *dev = dev_get_uclass_priv(udev);
487 struct ec_state *ec = dev_get_priv(dev->dev);
488 struct ec_host_request *req_hdr = (struct ec_host_request *)dev->dout;
489 const void *req_data = req_hdr + 1;
490 struct ec_host_response *resp_hdr = (struct ec_host_response *)dev->din;
491 void *resp_data = resp_hdr + 1;
494 len = process_cmd(ec, req_hdr, req_data, resp_hdr, resp_data);
498 resp_hdr->struct_version = 3;
499 resp_hdr->result = EC_RES_SUCCESS;
500 resp_hdr->data_len = len;
501 resp_hdr->reserved = 0;
502 len += sizeof(*resp_hdr);
503 resp_hdr->checksum = 0;
504 resp_hdr->checksum = (uint8_t)
505 -cros_ec_calc_checksum((const uint8_t *)resp_hdr, len);
510 void cros_ec_check_keyboard(struct udevice *dev)
512 struct ec_state *ec = dev_get_priv(dev);
515 printf("Press keys for EC to detect on reset (ESC=recovery)...");
516 start = get_timer(0);
517 while (get_timer(start) < 1000)
520 if (!sandbox_sdl_key_pressed(KEY_ESC)) {
521 ec->recovery_req = true;
522 printf(" - EC requests recovery\n");
526 void sandbox_cros_ec_set_test_flags(struct udevice *dev, uint flags)
528 struct ec_state *ec = dev_get_priv(dev);
530 ec->test_flags = flags;
533 int cros_ec_probe(struct udevice *dev)
535 struct ec_state *ec = dev_get_priv(dev);
536 struct cros_ec_dev *cdev = dev_get_uclass_priv(dev);
537 struct udevice *keyb_dev;
541 memcpy(ec, &s_state, sizeof(*ec));
542 err = cros_ec_decode_ec_flash(dev, &ec->ec_config);
544 debug("%s: Cannot device EC flash\n", __func__);
548 node = ofnode_null();
549 for (device_find_first_child(dev, &keyb_dev);
551 device_find_next_child(&keyb_dev)) {
552 if (device_get_uclass_id(keyb_dev) == UCLASS_KEYBOARD) {
553 node = dev_ofnode(keyb_dev);
557 if (!ofnode_valid(node)) {
558 debug("%s: No cros_ec keyboard found\n", __func__);
559 } else if (keyscan_read_fdt_matrix(ec, node)) {
560 debug("%s: Could not read key matrix\n", __func__);
564 /* If we loaded EC data, check that the length matches */
565 if (ec->flash_data &&
566 ec->flash_data_len != ec->ec_config.flash.length) {
567 printf("EC data length is %x, expected %x, discarding data\n",
568 ec->flash_data_len, ec->ec_config.flash.length);
569 free(ec->flash_data);
570 ec->flash_data = NULL;
573 /* Otherwise allocate the memory */
574 if (!ec->flash_data) {
575 ec->flash_data_len = ec->ec_config.flash.length;
576 ec->flash_data = malloc(ec->flash_data_len);
583 return cros_ec_register(dev);
586 struct dm_cros_ec_ops cros_ec_ops = {
587 .packet = cros_ec_sandbox_packet,
590 static const struct udevice_id cros_ec_ids[] = {
591 { .compatible = "google,cros-ec-sandbox" },
595 U_BOOT_DRIVER(google_cros_ec_sandbox) = {
596 .name = "google_cros_ec_sandbox",
597 .id = UCLASS_CROS_EC,
598 .of_match = cros_ec_ids,
599 .probe = cros_ec_probe,
600 .priv_auto = sizeof(struct ec_state),