2 * Chromium OS cros_ec driver - sandbox emulation
4 * Copyright (c) 2013 The Chromium OS Authors.
6 * SPDX-License-Identifier: GPL-2.0+
11 #include <ec_commands.h>
18 #include <asm/state.h>
20 #include <linux/input.h>
23 * Ultimately it shold be possible to connect an Chrome OS EC emulation
24 * to U-Boot and remove all of this code. But this provides a test
25 * environment for bringing up chromeos_sandbox and demonstrating its
28 * This emulation includes the following:
30 * 1. Emulation of the keyboard, by converting keypresses received from SDL
31 * into key scan data, passed back from the EC as key scan messages. The
32 * key layout is read from the device tree.
34 * 2. Emulation of vboot context - so this can be read/written as required.
36 * 3. Save/restore of EC state, so that the vboot context, flash memory
37 * contents and current image can be preserved across boots. This is important
38 * since the EC is supposed to continue running even if the AP resets.
40 * 4. Some event support, in particular allowing Escape to be pressed on boot
41 * to enter recovery mode. The EC passes this to U-Boot through the normal
44 * 5. Flash read/write/erase support, so that software sync works. The
45 * protect messages are supported but no protection is implemented.
47 * 6. Hashing of the EC image, again to support software sync.
49 * Other features can be added, although a better path is probably to link
50 * the EC image in with U-Boot (Vic has demonstrated a prototype for this).
53 DECLARE_GLOBAL_DATA_PTR
;
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
79 uint8_t vbnv_context
[EC_VBNV_BLOCK_SIZE
];
80 struct fdt_cros_ec ec_config
;
83 enum ec_current_image current_image
;
85 struct ec_keymatrix_entry
*matrix
; /* the key matrix info */
86 uint8_t keyscan
[KEYBOARD_COLS
];
91 * cros_ec_read_state() - read the sandbox EC state from the state file
93 * If data is available, then blob and node will provide access to it. If
94 * not this function sets up an empty EC.
96 * @param blob: Pointer to device tree blob, or NULL if no data to read
97 * @param node: Node offset to read from
99 static int cros_ec_read_state(const void *blob
, int node
)
101 struct ec_state
*ec
= &s_state
;
105 /* Set everything to defaults */
106 ec
->current_image
= EC_IMAGE_RO
;
110 /* Read the data if available */
111 ec
->current_image
= fdtdec_get_int(blob
, node
, "current-image",
113 prop
= fdt_getprop(blob
, node
, "vbnv-context", &len
);
114 if (prop
&& len
== sizeof(ec
->vbnv_context
))
115 memcpy(ec
->vbnv_context
, prop
, len
);
117 prop
= fdt_getprop(blob
, node
, "flash-data", &len
);
119 ec
->flash_data_len
= len
;
120 ec
->flash_data
= os_malloc(len
);
123 memcpy(ec
->flash_data
, prop
, len
);
124 debug("%s: Loaded EC flash data size %#x\n", __func__
, len
);
131 * cros_ec_write_state() - Write out our state to the state file
133 * The caller will ensure that there is a node ready for the state. The node
134 * may already contain the old state, in which case it is overridden.
136 * @param blob: Device tree blob holding state
137 * @param node: Node to write our state into
139 static int cros_ec_write_state(void *blob
, int node
)
141 struct ec_state
*ec
= &s_state
;
143 /* We are guaranteed enough space to write basic properties */
144 fdt_setprop_u32(blob
, node
, "current-image", ec
->current_image
);
145 fdt_setprop(blob
, node
, "vbnv-context", ec
->vbnv_context
,
146 sizeof(ec
->vbnv_context
));
147 return state_setprop(node
, "flash-data", ec
->flash_data
,
148 ec
->ec_config
.flash
.length
);
151 SANDBOX_STATE_IO(cros_ec
, "google,cros-ec", cros_ec_read_state
,
152 cros_ec_write_state
);
155 * Return the number of bytes used in the specified image.
157 * This is the actual size of code+data in the image, as opposed to the
158 * amount of space reserved in flash for that image. This code is similar to
159 * that used by the real EC code base.
161 * @param ec Current emulated EC state
162 * @param entry Flash map entry containing the image to check
163 * @return actual image size in bytes, 0 if the image contains no content or
166 static int get_image_used(struct ec_state
*ec
, struct fmap_entry
*entry
)
171 * Scan backwards looking for 0xea byte, which is by definition the
172 * last byte of the image. See ec.lds.S for how this is inserted at
173 * the end of the image.
175 for (size
= entry
->length
- 1;
176 size
> 0 && ec
->flash_data
[entry
->offset
+ size
] != 0xea;
180 return size
? size
+ 1 : 0; /* 0xea byte IS part of the image */
184 * Read the key matrix from the device tree
186 * Keymap entries in the fdt take the form of 0xRRCCKKKK where
187 * RR=Row CC=Column KKKK=Key Code
189 * @param ec Current emulated EC state
190 * @param blob Device tree blob containing keyscan information
191 * @param node Keyboard node of device tree containing keyscan information
192 * @return 0 if ok, -1 on error
194 static int keyscan_read_fdt_matrix(struct ec_state
*ec
, const void *blob
,
201 cell
= fdt_getprop(blob
, 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;
304 case EC_CMD_GET_VERSION
: {
305 struct ec_response_get_version
*resp
= resp_data
;
307 strcpy(resp
->version_string_ro
, "sandbox_ro");
308 strcpy(resp
->version_string_rw
, "sandbox_rw");
309 resp
->current_image
= ec
->current_image
;
310 debug("Current image %d\n", resp
->current_image
);
314 case EC_CMD_VBNV_CONTEXT
: {
315 const struct ec_params_vbnvcontext
*req
= req_data
;
316 struct ec_response_vbnvcontext
*resp
= resp_data
;
319 case EC_VBNV_CONTEXT_OP_READ
:
320 memcpy(resp
->block
, ec
->vbnv_context
,
321 sizeof(resp
->block
));
324 case EC_VBNV_CONTEXT_OP_WRITE
:
325 memcpy(ec
->vbnv_context
, resp
->block
,
326 sizeof(resp
->block
));
330 printf(" ** Unknown vbnv_context command %#02x\n",
336 case EC_CMD_REBOOT_EC
: {
337 const struct ec_params_reboot_ec
*req
= req_data
;
339 printf("Request reboot type %d\n", req
->cmd
);
341 case EC_REBOOT_DISABLE_JUMP
:
344 case EC_REBOOT_JUMP_RW
:
345 ec
->current_image
= EC_IMAGE_RW
;
349 puts(" ** Unknown type");
354 case EC_CMD_HOST_EVENT_GET_B
: {
355 struct ec_response_host_event_mask
*resp
= resp_data
;
358 if (ec
->recovery_req
) {
359 resp
->mask
|= EC_HOST_EVENT_MASK(
360 EC_HOST_EVENT_KEYBOARD_RECOVERY
);
366 case EC_CMD_VBOOT_HASH
: {
367 const struct ec_params_vboot_hash
*req
= req_data
;
368 struct ec_response_vboot_hash
*resp
= resp_data
;
369 struct fmap_entry
*entry
;
372 entry
= &state
->ec_config
.region
[EC_FLASH_REGION_RW
];
375 case EC_VBOOT_HASH_RECALC
:
376 case EC_VBOOT_HASH_GET
:
377 size
= SHA256_SUM_LEN
;
378 len
= get_image_used(ec
, entry
);
379 ret
= hash_block("sha256",
380 ec
->flash_data
+ entry
->offset
,
381 len
, resp
->hash_digest
, &size
);
383 printf(" ** hash_block() failed\n");
386 resp
->status
= EC_VBOOT_HASH_STATUS_DONE
;
387 resp
->hash_type
= EC_VBOOT_HASH_TYPE_SHA256
;
388 resp
->digest_size
= size
;
390 resp
->offset
= entry
->offset
;
395 printf(" ** EC_CMD_VBOOT_HASH: Unknown command %d\n",
401 case EC_CMD_FLASH_PROTECT
: {
402 const struct ec_params_flash_protect
*req
= req_data
;
403 struct ec_response_flash_protect
*resp
= resp_data
;
404 uint32_t expect
= EC_FLASH_PROTECT_ALL_NOW
|
405 EC_FLASH_PROTECT_ALL_AT_BOOT
;
407 printf("mask=%#x, flags=%#x\n", req
->mask
, req
->flags
);
408 if (req
->flags
== expect
|| req
->flags
== 0) {
409 resp
->flags
= req
->flags
? EC_FLASH_PROTECT_ALL_NOW
:
411 resp
->valid_flags
= EC_FLASH_PROTECT_ALL_NOW
;
412 resp
->writable_flags
= 0;
415 puts(" ** unexpected flash protect request\n");
420 case EC_CMD_FLASH_REGION_INFO
: {
421 const struct ec_params_flash_region_info
*req
= req_data
;
422 struct ec_response_flash_region_info
*resp
= resp_data
;
423 struct fmap_entry
*entry
;
425 switch (req
->region
) {
426 case EC_FLASH_REGION_RO
:
427 case EC_FLASH_REGION_RW
:
428 case EC_FLASH_REGION_WP_RO
:
429 entry
= &state
->ec_config
.region
[req
->region
];
430 resp
->offset
= entry
->offset
;
431 resp
->size
= entry
->length
;
433 printf("EC flash region %d: offset=%#x, size=%#x\n",
434 req
->region
, resp
->offset
, resp
->size
);
437 printf("** Unknown flash region %d\n", req
->region
);
442 case EC_CMD_FLASH_ERASE
: {
443 const struct ec_params_flash_erase
*req
= req_data
;
445 memset(ec
->flash_data
+ req
->offset
,
446 ec
->ec_config
.flash_erase_value
,
451 case EC_CMD_FLASH_WRITE
: {
452 const struct ec_params_flash_write
*req
= req_data
;
454 memcpy(ec
->flash_data
+ req
->offset
, req
+ 1, req
->size
);
458 case EC_CMD_MKBP_STATE
:
459 len
= cros_ec_keyscan(ec
, resp_data
);
462 printf(" ** Unknown EC command %#02x\n", req_hdr
->command
);
469 int cros_ec_sandbox_packet(struct cros_ec_dev
*dev
, int out_bytes
,
472 struct ec_host_request
*req_hdr
= (struct ec_host_request
*)dev
->dout
;
473 const void *req_data
= req_hdr
+ 1;
474 struct ec_host_response
*resp_hdr
= (struct ec_host_response
*)dev
->din
;
475 void *resp_data
= resp_hdr
+ 1;
478 len
= process_cmd(&s_state
, req_hdr
, req_data
, resp_hdr
, resp_data
);
482 resp_hdr
->struct_version
= 3;
483 resp_hdr
->result
= EC_RES_SUCCESS
;
484 resp_hdr
->data_len
= len
;
485 resp_hdr
->reserved
= 0;
486 len
+= sizeof(*resp_hdr
);
487 resp_hdr
->checksum
= 0;
488 resp_hdr
->checksum
= (uint8_t)
489 -cros_ec_calc_checksum((const uint8_t *)resp_hdr
, len
);
494 int cros_ec_sandbox_decode_fdt(struct cros_ec_dev
*dev
, const void *blob
)
499 void cros_ec_check_keyboard(struct cros_ec_dev
*dev
)
501 struct ec_state
*ec
= &s_state
;
504 printf("Press keys for EC to detect on reset (ESC=recovery)...");
505 start
= get_timer(0);
506 while (get_timer(start
) < 1000)
509 if (!sandbox_sdl_key_pressed(KEY_ESC
)) {
510 ec
->recovery_req
= true;
511 printf(" - EC requests recovery\n");
516 * Initialize sandbox EC emulation.
518 * @param dev CROS_EC device
519 * @param blob Device tree blob
520 * @return 0 if ok, -1 on error
522 int cros_ec_sandbox_init(struct cros_ec_dev
*dev
, const void *blob
)
524 struct ec_state
*ec
= &s_state
;
529 err
= cros_ec_decode_ec_flash(blob
, &ec
->ec_config
);
533 node
= fdtdec_next_compatible(blob
, 0, COMPAT_GOOGLE_CROS_EC_KEYB
);
535 debug("%s: No cros_ec keyboard found\n", __func__
);
536 } else if (keyscan_read_fdt_matrix(ec
, blob
, node
)) {
537 debug("%s: Could not read key matrix\n", __func__
);
541 /* If we loaded EC data, check that the length matches */
542 if (ec
->flash_data
&&
543 ec
->flash_data_len
!= ec
->ec_config
.flash
.length
) {
544 printf("EC data length is %x, expected %x, discarding data\n",
545 ec
->flash_data_len
, ec
->ec_config
.flash
.length
);
546 os_free(ec
->flash_data
);
547 ec
->flash_data
= NULL
;
550 /* Otherwise allocate the memory */
551 if (!ec
->flash_data
) {
552 ec
->flash_data_len
= ec
->ec_config
.flash
.length
;
553 ec
->flash_data
= os_malloc(ec
->flash_data_len
);