2 * Chromium OS cros_ec driver - sandbox emulation
4 * Copyright (c) 2013 The Chromium OS Authors.
6 * SPDX-License-Identifier: GPL-2.0+
12 #include <ec_commands.h>
17 #include <u-boot/sha256.h>
19 #include <asm/state.h>
21 #include <linux/input.h>
24 * Ultimately it shold be possible to connect an Chrome OS EC emulation
25 * to U-Boot and remove all of this code. But this provides a test
26 * environment for bringing up chromeos_sandbox and demonstrating its
29 * This emulation includes the following:
31 * 1. Emulation of the keyboard, by converting keypresses received from SDL
32 * into key scan data, passed back from the EC as key scan messages. The
33 * key layout is read from the device tree.
35 * 2. Emulation of vboot context - so this can be read/written as required.
37 * 3. Save/restore of EC state, so that the vboot context, flash memory
38 * contents and current image can be preserved across boots. This is important
39 * since the EC is supposed to continue running even if the AP resets.
41 * 4. Some event support, in particular allowing Escape to be pressed on boot
42 * to enter recovery mode. The EC passes this to U-Boot through the normal
45 * 5. Flash read/write/erase support, so that software sync works. The
46 * protect messages are supported but no protection is implemented.
48 * 6. Hashing of the EC image, again to support software sync.
50 * Other features can be added, although a better path is probably to link
51 * the EC image in with U-Boot (Vic has demonstrated a prototype for this).
54 #define KEYBOARD_ROWS 8
55 #define KEYBOARD_COLS 13
57 /* A single entry of the key matrix */
58 struct ec_keymatrix_entry {
59 int row; /* key matrix row */
60 int col; /* key matrix column */
61 int keycode; /* corresponding linux key code */
65 * struct ec_state - Information about the EC state
67 * @vbnv_context: Vboot context data stored by EC
68 * @ec_config: FDT config information about the EC (e.g. flashmap)
69 * @flash_data: Contents of flash memory
70 * @flash_data_len: Size of flash memory
71 * @current_image: Current image the EC is running
72 * @matrix_count: Number of keys to decode in matrix
73 * @matrix: Information about keyboard matrix
74 * @keyscan: Current keyscan information (bit set for each row/column pressed)
75 * @recovery_req: Keyboard recovery requested
78 uint8_t vbnv_context[EC_VBNV_BLOCK_SIZE];
79 struct fdt_cros_ec ec_config;
82 enum ec_current_image current_image;
84 struct ec_keymatrix_entry *matrix; /* the key matrix info */
85 uint8_t keyscan[KEYBOARD_COLS];
90 * cros_ec_read_state() - read the sandbox EC state from the state file
92 * If data is available, then blob and node will provide access to it. If
93 * not this function sets up an empty EC.
95 * @param blob: Pointer to device tree blob, or NULL if no data to read
96 * @param node: Node offset to read from
98 static int cros_ec_read_state(const void *blob, int node)
100 struct ec_state *ec = &s_state;
104 /* Set everything to defaults */
105 ec->current_image = EC_IMAGE_RO;
109 /* Read the data if available */
110 ec->current_image = fdtdec_get_int(blob, node, "current-image",
112 prop = fdt_getprop(blob, node, "vbnv-context", &len);
113 if (prop && len == sizeof(ec->vbnv_context))
114 memcpy(ec->vbnv_context, prop, len);
116 prop = fdt_getprop(blob, node, "flash-data", &len);
118 ec->flash_data_len = len;
119 ec->flash_data = os_malloc(len);
122 memcpy(ec->flash_data, prop, len);
123 debug("%s: Loaded EC flash data size %#x\n", __func__, len);
130 * cros_ec_write_state() - Write out our state to the state file
132 * The caller will ensure that there is a node ready for the state. The node
133 * may already contain the old state, in which case it is overridden.
135 * @param blob: Device tree blob holding state
136 * @param node: Node to write our state into
138 static int cros_ec_write_state(void *blob, int node)
140 struct ec_state *ec = g_state;
142 /* We are guaranteed enough space to write basic properties */
143 fdt_setprop_u32(blob, node, "current-image", ec->current_image);
144 fdt_setprop(blob, node, "vbnv-context", ec->vbnv_context,
145 sizeof(ec->vbnv_context));
146 return state_setprop(node, "flash-data", ec->flash_data,
147 ec->ec_config.flash.length);
150 SANDBOX_STATE_IO(cros_ec, "google,cros-ec", cros_ec_read_state,
151 cros_ec_write_state);
154 * Return the number of bytes used in the specified image.
156 * This is the actual size of code+data in the image, as opposed to the
157 * amount of space reserved in flash for that image. This code is similar to
158 * that used by the real EC code base.
160 * @param ec Current emulated EC state
161 * @param entry Flash map entry containing the image to check
162 * @return actual image size in bytes, 0 if the image contains no content or
165 static int get_image_used(struct ec_state *ec, struct fmap_entry *entry)
170 * Scan backwards looking for 0xea byte, which is by definition the
171 * last byte of the image. See ec.lds.S for how this is inserted at
172 * the end of the image.
174 for (size = entry->length - 1;
175 size > 0 && ec->flash_data[entry->offset + size] != 0xea;
179 return size ? size + 1 : 0; /* 0xea byte IS part of the image */
183 * Read the key matrix from the device tree
185 * Keymap entries in the fdt take the form of 0xRRCCKKKK where
186 * RR=Row CC=Column KKKK=Key Code
188 * @param ec Current emulated EC state
189 * @param node Keyboard node of device tree containing keyscan information
190 * @return 0 if ok, -1 on error
192 static int keyscan_read_fdt_matrix(struct ec_state *ec, ofnode node)
198 cell = ofnode_get_property(node, "linux,keymap", &len);
199 ec->matrix_count = len / 4;
200 ec->matrix = calloc(ec->matrix_count, sizeof(*ec->matrix));
202 debug("%s: Out of memory for key matrix\n", __func__);
206 /* Now read the data */
207 for (upto = 0; upto < ec->matrix_count; upto++) {
208 struct ec_keymatrix_entry *matrix = &ec->matrix[upto];
211 word = fdt32_to_cpu(*cell++);
212 matrix->row = word >> 24;
213 matrix->col = (word >> 16) & 0xff;
214 matrix->keycode = word & 0xffff;
216 /* Hard-code some sanity limits for now */
217 if (matrix->row >= KEYBOARD_ROWS ||
218 matrix->col >= KEYBOARD_COLS) {
219 debug("%s: Matrix pos out of range (%d,%d)\n",
220 __func__, matrix->row, matrix->col);
225 if (upto != ec->matrix_count) {
226 debug("%s: Read mismatch from key matrix\n", __func__);
234 * Return the next keyscan message contents
236 * @param ec Current emulated EC state
237 * @param scan Place to put keyscan bytes for the keyscan message (must hold
238 * enough space for a full keyscan)
239 * @return number of bytes of valid scan data
241 static int cros_ec_keyscan(struct ec_state *ec, uint8_t *scan)
243 const struct ec_keymatrix_entry *matrix;
244 int bytes = KEYBOARD_COLS;
245 int key[8]; /* allow up to 8 keys to be pressed at once */
249 memset(ec->keyscan, '\0', bytes);
250 count = sandbox_sdl_scan_keys(key, ARRAY_SIZE(key));
252 /* Look up keycode in matrix */
253 for (i = 0, matrix = ec->matrix; i < ec->matrix_count; i++, matrix++) {
257 for (found = false, j = 0; j < count; j++) {
258 if (matrix->keycode == key[j])
263 debug("%d: %d,%d\n", matrix->keycode, matrix->row,
265 ec->keyscan[matrix->col] |= 1 << matrix->row;
269 memcpy(scan, ec->keyscan, bytes);
274 * Process an emulated EC command
276 * @param ec Current emulated EC state
277 * @param req_hdr Pointer to request header
278 * @param req_data Pointer to body of request
279 * @param resp_hdr Pointer to place to put response header
280 * @param resp_data Pointer to place to put response data, if any
281 * @return length of response data, or 0 for no response data, or -1 on error
283 static int process_cmd(struct ec_state *ec,
284 struct ec_host_request *req_hdr, const void *req_data,
285 struct ec_host_response *resp_hdr, void *resp_data)
289 /* TODO(sjg@chromium.org): Check checksums */
290 debug("EC command %#0x\n", req_hdr->command);
292 switch (req_hdr->command) {
294 const struct ec_params_hello *req = req_data;
295 struct ec_response_hello *resp = resp_data;
297 resp->out_data = req->in_data + 0x01020304;
301 case EC_CMD_GET_VERSION: {
302 struct ec_response_get_version *resp = resp_data;
304 strcpy(resp->version_string_ro, "sandbox_ro");
305 strcpy(resp->version_string_rw, "sandbox_rw");
306 resp->current_image = ec->current_image;
307 debug("Current image %d\n", resp->current_image);
311 case EC_CMD_VBNV_CONTEXT: {
312 const struct ec_params_vbnvcontext *req = req_data;
313 struct ec_response_vbnvcontext *resp = resp_data;
316 case EC_VBNV_CONTEXT_OP_READ:
317 memcpy(resp->block, ec->vbnv_context,
318 sizeof(resp->block));
321 case EC_VBNV_CONTEXT_OP_WRITE:
322 memcpy(ec->vbnv_context, resp->block,
323 sizeof(resp->block));
327 printf(" ** Unknown vbnv_context command %#02x\n",
333 case EC_CMD_REBOOT_EC: {
334 const struct ec_params_reboot_ec *req = req_data;
336 printf("Request reboot type %d\n", req->cmd);
338 case EC_REBOOT_DISABLE_JUMP:
341 case EC_REBOOT_JUMP_RW:
342 ec->current_image = EC_IMAGE_RW;
346 puts(" ** Unknown type");
351 case EC_CMD_HOST_EVENT_GET_B: {
352 struct ec_response_host_event_mask *resp = resp_data;
355 if (ec->recovery_req) {
356 resp->mask |= EC_HOST_EVENT_MASK(
357 EC_HOST_EVENT_KEYBOARD_RECOVERY);
363 case EC_CMD_VBOOT_HASH: {
364 const struct ec_params_vboot_hash *req = req_data;
365 struct ec_response_vboot_hash *resp = resp_data;
366 struct fmap_entry *entry;
369 entry = &ec->ec_config.region[EC_FLASH_REGION_RW];
372 case EC_VBOOT_HASH_RECALC:
373 case EC_VBOOT_HASH_GET:
374 size = SHA256_SUM_LEN;
375 len = get_image_used(ec, entry);
376 ret = hash_block("sha256",
377 ec->flash_data + entry->offset,
378 len, resp->hash_digest, &size);
380 printf(" ** hash_block() failed\n");
383 resp->status = EC_VBOOT_HASH_STATUS_DONE;
384 resp->hash_type = EC_VBOOT_HASH_TYPE_SHA256;
385 resp->digest_size = size;
387 resp->offset = entry->offset;
392 printf(" ** EC_CMD_VBOOT_HASH: Unknown command %d\n",
398 case EC_CMD_FLASH_PROTECT: {
399 const struct ec_params_flash_protect *req = req_data;
400 struct ec_response_flash_protect *resp = resp_data;
401 uint32_t expect = EC_FLASH_PROTECT_ALL_NOW |
402 EC_FLASH_PROTECT_ALL_AT_BOOT;
404 printf("mask=%#x, flags=%#x\n", req->mask, req->flags);
405 if (req->flags == expect || req->flags == 0) {
406 resp->flags = req->flags ? EC_FLASH_PROTECT_ALL_NOW :
408 resp->valid_flags = EC_FLASH_PROTECT_ALL_NOW;
409 resp->writable_flags = 0;
412 puts(" ** unexpected flash protect request\n");
417 case EC_CMD_FLASH_REGION_INFO: {
418 const struct ec_params_flash_region_info *req = req_data;
419 struct ec_response_flash_region_info *resp = resp_data;
420 struct fmap_entry *entry;
422 switch (req->region) {
423 case EC_FLASH_REGION_RO:
424 case EC_FLASH_REGION_RW:
425 case EC_FLASH_REGION_WP_RO:
426 entry = &ec->ec_config.region[req->region];
427 resp->offset = entry->offset;
428 resp->size = entry->length;
430 printf("EC flash region %d: offset=%#x, size=%#x\n",
431 req->region, resp->offset, resp->size);
434 printf("** Unknown flash region %d\n", req->region);
439 case EC_CMD_FLASH_ERASE: {
440 const struct ec_params_flash_erase *req = req_data;
442 memset(ec->flash_data + req->offset,
443 ec->ec_config.flash_erase_value,
448 case EC_CMD_FLASH_WRITE: {
449 const struct ec_params_flash_write *req = req_data;
451 memcpy(ec->flash_data + req->offset, req + 1, req->size);
455 case EC_CMD_MKBP_STATE:
456 len = cros_ec_keyscan(ec, resp_data);
458 case EC_CMD_ENTERING_MODE:
462 printf(" ** Unknown EC command %#02x\n", req_hdr->command);
469 int cros_ec_sandbox_packet(struct udevice *udev, int out_bytes, int in_bytes)
471 struct cros_ec_dev *dev = dev_get_uclass_priv(udev);
472 struct ec_state *ec = dev_get_priv(dev->dev);
473 struct ec_host_request *req_hdr = (struct ec_host_request *)dev->dout;
474 const void *req_data = req_hdr + 1;
475 struct ec_host_response *resp_hdr = (struct ec_host_response *)dev->din;
476 void *resp_data = resp_hdr + 1;
479 len = process_cmd(ec, req_hdr, req_data, resp_hdr, resp_data);
483 resp_hdr->struct_version = 3;
484 resp_hdr->result = EC_RES_SUCCESS;
485 resp_hdr->data_len = len;
486 resp_hdr->reserved = 0;
487 len += sizeof(*resp_hdr);
488 resp_hdr->checksum = 0;
489 resp_hdr->checksum = (uint8_t)
490 -cros_ec_calc_checksum((const uint8_t *)resp_hdr, len);
495 void cros_ec_check_keyboard(struct cros_ec_dev *dev)
497 struct ec_state *ec = dev_get_priv(dev->dev);
500 printf("Press keys for EC to detect on reset (ESC=recovery)...");
501 start = get_timer(0);
502 while (get_timer(start) < 1000)
505 if (!sandbox_sdl_key_pressed(KEY_ESC)) {
506 ec->recovery_req = true;
507 printf(" - EC requests recovery\n");
511 int cros_ec_probe(struct udevice *dev)
513 struct ec_state *ec = dev->priv;
514 struct cros_ec_dev *cdev = dev->uclass_priv;
515 struct udevice *keyb_dev;
519 memcpy(ec, &s_state, sizeof(*ec));
520 err = cros_ec_decode_ec_flash(dev, &ec->ec_config);
522 debug("%s: Cannot device EC flash\n", __func__);
526 node = ofnode_null();
527 for (device_find_first_child(dev, &keyb_dev);
529 device_find_next_child(&keyb_dev)) {
530 if (device_get_uclass_id(keyb_dev) == UCLASS_KEYBOARD) {
531 node = dev_ofnode(keyb_dev);
535 if (!ofnode_valid(node)) {
536 debug("%s: No cros_ec keyboard found\n", __func__);
537 } else if (keyscan_read_fdt_matrix(ec, node)) {
538 debug("%s: Could not read key matrix\n", __func__);
542 /* If we loaded EC data, check that the length matches */
543 if (ec->flash_data &&
544 ec->flash_data_len != ec->ec_config.flash.length) {
545 printf("EC data length is %x, expected %x, discarding data\n",
546 ec->flash_data_len, ec->ec_config.flash.length);
547 os_free(ec->flash_data);
548 ec->flash_data = NULL;
551 /* Otherwise allocate the memory */
552 if (!ec->flash_data) {
553 ec->flash_data_len = ec->ec_config.flash.length;
554 ec->flash_data = os_malloc(ec->flash_data_len);
561 return cros_ec_register(dev);
564 struct dm_cros_ec_ops cros_ec_ops = {
565 .packet = cros_ec_sandbox_packet,
568 static const struct udevice_id cros_ec_ids[] = {
569 { .compatible = "google,cros-ec-sandbox" },
573 U_BOOT_DRIVER(cros_ec_sandbox) = {
574 .name = "cros_ec_sandbox",
575 .id = UCLASS_CROS_EC,
576 .of_match = cros_ec_ids,
577 .probe = cros_ec_probe,
578 .priv_auto_alloc_size = sizeof(struct ec_state),