u-boot/drivers/misc/cros_ec_sandbox.c

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// SPDX-License-Identifier: GPL-2.0+
/*
* Chromium OS cros_ec driver - sandbox emulation
*
* Copyright (c) 2013 The Chromium OS Authors.
*/
#include <common.h>
#include <cros_ec.h>
#include <dm.h>
#include <ec_commands.h>
#include <errno.h>
#include <hash.h>
#include <malloc.h>
#include <os.h>
#include <u-boot/sha256.h>
#include <spi.h>
#include <asm/state.h>
#include <asm/sdl.h>
#include <linux/input.h>
/*
* Ultimately it shold be possible to connect an Chrome OS EC emulation
* to U-Boot and remove all of this code. But this provides a test
* environment for bringing up chromeos_sandbox and demonstrating its
* utility.
*
* This emulation includes the following:
*
* 1. Emulation of the keyboard, by converting keypresses received from SDL
* into key scan data, passed back from the EC as key scan messages. The
* key layout is read from the device tree.
*
* 2. Emulation of vboot context - so this can be read/written as required.
*
* 3. Save/restore of EC state, so that the vboot context, flash memory
* contents and current image can be preserved across boots. This is important
* since the EC is supposed to continue running even if the AP resets.
*
* 4. Some event support, in particular allowing Escape to be pressed on boot
* to enter recovery mode. The EC passes this to U-Boot through the normal
* event message.
*
* 5. Flash read/write/erase support, so that software sync works. The
* protect messages are supported but no protection is implemented.
*
* 6. Hashing of the EC image, again to support software sync.
*
* Other features can be added, although a better path is probably to link
* the EC image in with U-Boot (Vic has demonstrated a prototype for this).
*/
#define KEYBOARD_ROWS 8
#define KEYBOARD_COLS 13
/* A single entry of the key matrix */
struct ec_keymatrix_entry {
int row; /* key matrix row */
int col; /* key matrix column */
int keycode; /* corresponding linux key code */
};
/**
* struct ec_state - Information about the EC state
*
* @vbnv_context: Vboot context data stored by EC
* @ec_config: FDT config information about the EC (e.g. flashmap)
* @flash_data: Contents of flash memory
* @flash_data_len: Size of flash memory
* @current_image: Current image the EC is running
* @matrix_count: Number of keys to decode in matrix
* @matrix: Information about keyboard matrix
* @keyscan: Current keyscan information (bit set for each row/column pressed)
* @recovery_req: Keyboard recovery requested
*/
struct ec_state {
u8 vbnv_context[EC_VBNV_BLOCK_SIZE_V2];
struct fdt_cros_ec ec_config;
uint8_t *flash_data;
int flash_data_len;
enum ec_current_image current_image;
int matrix_count;
struct ec_keymatrix_entry *matrix; /* the key matrix info */
uint8_t keyscan[KEYBOARD_COLS];
bool recovery_req;
} s_state, *g_state;
/**
* cros_ec_read_state() - read the sandbox EC state from the state file
*
* If data is available, then blob and node will provide access to it. If
* not this function sets up an empty EC.
*
* @param blob: Pointer to device tree blob, or NULL if no data to read
* @param node: Node offset to read from
*/
static int cros_ec_read_state(const void *blob, int node)
{
struct ec_state *ec = &s_state;
const char *prop;
int len;
/* Set everything to defaults */
ec->current_image = EC_IMAGE_RO;
if (!blob)
return 0;
/* Read the data if available */
ec->current_image = fdtdec_get_int(blob, node, "current-image",
EC_IMAGE_RO);
prop = fdt_getprop(blob, node, "vbnv-context", &len);
if (prop && len == sizeof(ec->vbnv_context))
memcpy(ec->vbnv_context, prop, len);
prop = fdt_getprop(blob, node, "flash-data", &len);
if (prop) {
ec->flash_data_len = len;
ec->flash_data = os_malloc(len);
if (!ec->flash_data)
return -ENOMEM;
memcpy(ec->flash_data, prop, len);
debug("%s: Loaded EC flash data size %#x\n", __func__, len);
}
return 0;
}
/**
* cros_ec_write_state() - Write out our state to the state file
*
* The caller will ensure that there is a node ready for the state. The node
* may already contain the old state, in which case it is overridden.
*
* @param blob: Device tree blob holding state
* @param node: Node to write our state into
*/
static int cros_ec_write_state(void *blob, int node)
{
struct ec_state *ec = g_state;
/* We are guaranteed enough space to write basic properties */
fdt_setprop_u32(blob, node, "current-image", ec->current_image);
fdt_setprop(blob, node, "vbnv-context", ec->vbnv_context,
sizeof(ec->vbnv_context));
return state_setprop(node, "flash-data", ec->flash_data,
ec->ec_config.flash.length);
}
SANDBOX_STATE_IO(cros_ec, "google,cros-ec", cros_ec_read_state,
cros_ec_write_state);
/**
* Return the number of bytes used in the specified image.
*
* This is the actual size of code+data in the image, as opposed to the
* amount of space reserved in flash for that image. This code is similar to
* that used by the real EC code base.
*
* @param ec Current emulated EC state
* @param entry Flash map entry containing the image to check
* @return actual image size in bytes, 0 if the image contains no content or
* error.
*/
static int get_image_used(struct ec_state *ec, struct fmap_entry *entry)
{
int size;
/*
* Scan backwards looking for 0xea byte, which is by definition the
* last byte of the image. See ec.lds.S for how this is inserted at
* the end of the image.
*/
for (size = entry->length - 1;
size > 0 && ec->flash_data[entry->offset + size] != 0xea;
size--)
;
return size ? size + 1 : 0; /* 0xea byte IS part of the image */
}
/**
* Read the key matrix from the device tree
*
* Keymap entries in the fdt take the form of 0xRRCCKKKK where
* RR=Row CC=Column KKKK=Key Code
*
* @param ec Current emulated EC state
* @param node Keyboard node of device tree containing keyscan information
* @return 0 if ok, -1 on error
*/
static int keyscan_read_fdt_matrix(struct ec_state *ec, ofnode node)
{
const u32 *cell;
int upto;
int len;
cell = ofnode_get_property(node, "linux,keymap", &len);
ec->matrix_count = len / 4;
ec->matrix = calloc(ec->matrix_count, sizeof(*ec->matrix));
if (!ec->matrix) {
debug("%s: Out of memory for key matrix\n", __func__);
return -1;
}
/* Now read the data */
for (upto = 0; upto < ec->matrix_count; upto++) {
struct ec_keymatrix_entry *matrix = &ec->matrix[upto];
u32 word;
word = fdt32_to_cpu(*cell++);
matrix->row = word >> 24;
matrix->col = (word >> 16) & 0xff;
matrix->keycode = word & 0xffff;
/* Hard-code some sanity limits for now */
if (matrix->row >= KEYBOARD_ROWS ||
matrix->col >= KEYBOARD_COLS) {
debug("%s: Matrix pos out of range (%d,%d)\n",
__func__, matrix->row, matrix->col);
return -1;
}
}
if (upto != ec->matrix_count) {
debug("%s: Read mismatch from key matrix\n", __func__);
return -1;
}
return 0;
}
/**
* Return the next keyscan message contents
*
* @param ec Current emulated EC state
* @param scan Place to put keyscan bytes for the keyscan message (must hold
* enough space for a full keyscan)
* @return number of bytes of valid scan data
*/
static int cros_ec_keyscan(struct ec_state *ec, uint8_t *scan)
{
const struct ec_keymatrix_entry *matrix;
int bytes = KEYBOARD_COLS;
int key[8]; /* allow up to 8 keys to be pressed at once */
int count;
int i;
memset(ec->keyscan, '\0', bytes);
count = sandbox_sdl_scan_keys(key, ARRAY_SIZE(key));
/* Look up keycode in matrix */
for (i = 0, matrix = ec->matrix; i < ec->matrix_count; i++, matrix++) {
bool found;
int j;
for (found = false, j = 0; j < count; j++) {
if (matrix->keycode == key[j])
found = true;
}
if (found) {
debug("%d: %d,%d\n", matrix->keycode, matrix->row,
matrix->col);
ec->keyscan[matrix->col] |= 1 << matrix->row;
}
}
memcpy(scan, ec->keyscan, bytes);
return bytes;
}
/**
* Process an emulated EC command
*
* @param ec Current emulated EC state
* @param req_hdr Pointer to request header
* @param req_data Pointer to body of request
* @param resp_hdr Pointer to place to put response header
* @param resp_data Pointer to place to put response data, if any
* @return length of response data, or 0 for no response data, or -1 on error
*/
static int process_cmd(struct ec_state *ec,
struct ec_host_request *req_hdr, const void *req_data,
struct ec_host_response *resp_hdr, void *resp_data)
{
int len;
/* TODO(sjg@chromium.org): Check checksums */
debug("EC command %#0x\n", req_hdr->command);
switch (req_hdr->command) {
case EC_CMD_HELLO: {
const struct ec_params_hello *req = req_data;
struct ec_response_hello *resp = resp_data;
resp->out_data = req->in_data + 0x01020304;
len = sizeof(*resp);
break;
}
case EC_CMD_GET_VERSION: {
struct ec_response_get_version *resp = resp_data;
strcpy(resp->version_string_ro, "sandbox_ro");
strcpy(resp->version_string_rw, "sandbox_rw");
resp->current_image = ec->current_image;
debug("Current image %d\n", resp->current_image);
len = sizeof(*resp);
break;
}
case EC_CMD_VBNV_CONTEXT: {
const struct ec_params_vbnvcontext *req = req_data;
struct ec_response_vbnvcontext *resp = resp_data;
switch (req->op) {
case EC_VBNV_CONTEXT_OP_READ:
memcpy(resp->block, ec->vbnv_context,
sizeof(resp->block));
len = sizeof(*resp);
break;
case EC_VBNV_CONTEXT_OP_WRITE:
memcpy(ec->vbnv_context, resp->block,
sizeof(resp->block));
len = 0;
break;
default:
printf(" ** Unknown vbnv_context command %#02x\n",
req->op);
return -1;
}
break;
}
case EC_CMD_REBOOT_EC: {
const struct ec_params_reboot_ec *req = req_data;
printf("Request reboot type %d\n", req->cmd);
switch (req->cmd) {
case EC_REBOOT_DISABLE_JUMP:
len = 0;
break;
case EC_REBOOT_JUMP_RW:
ec->current_image = EC_IMAGE_RW;
len = 0;
break;
default:
puts(" ** Unknown type");
return -1;
}
break;
}
case EC_CMD_HOST_EVENT_GET_B: {
struct ec_response_host_event_mask *resp = resp_data;
resp->mask = 0;
if (ec->recovery_req) {
resp->mask |= EC_HOST_EVENT_MASK(
EC_HOST_EVENT_KEYBOARD_RECOVERY);
}
len = sizeof(*resp);
break;
}
case EC_CMD_VBOOT_HASH: {
const struct ec_params_vboot_hash *req = req_data;
struct ec_response_vboot_hash *resp = resp_data;
struct fmap_entry *entry;
int ret, size;
entry = &ec->ec_config.region[EC_FLASH_REGION_ACTIVE];
switch (req->cmd) {
case EC_VBOOT_HASH_RECALC:
case EC_VBOOT_HASH_GET:
size = SHA256_SUM_LEN;
len = get_image_used(ec, entry);
ret = hash_block("sha256",
ec->flash_data + entry->offset,
len, resp->hash_digest, &size);
if (ret) {
printf(" ** hash_block() failed\n");
return -1;
}
resp->status = EC_VBOOT_HASH_STATUS_DONE;
resp->hash_type = EC_VBOOT_HASH_TYPE_SHA256;
resp->digest_size = size;
resp->reserved0 = 0;
resp->offset = entry->offset;
resp->size = len;
len = sizeof(*resp);
break;
default:
printf(" ** EC_CMD_VBOOT_HASH: Unknown command %d\n",
req->cmd);
return -1;
}
break;
}
case EC_CMD_FLASH_PROTECT: {
const struct ec_params_flash_protect *req = req_data;
struct ec_response_flash_protect *resp = resp_data;
uint32_t expect = EC_FLASH_PROTECT_ALL_NOW |
EC_FLASH_PROTECT_ALL_AT_BOOT;
printf("mask=%#x, flags=%#x\n", req->mask, req->flags);
if (req->flags == expect || req->flags == 0) {
resp->flags = req->flags ? EC_FLASH_PROTECT_ALL_NOW :
0;
resp->valid_flags = EC_FLASH_PROTECT_ALL_NOW;
resp->writable_flags = 0;
len = sizeof(*resp);
} else {
puts(" ** unexpected flash protect request\n");
return -1;
}
break;
}
case EC_CMD_FLASH_REGION_INFO: {
const struct ec_params_flash_region_info *req = req_data;
struct ec_response_flash_region_info *resp = resp_data;
struct fmap_entry *entry;
switch (req->region) {
case EC_FLASH_REGION_RO:
case EC_FLASH_REGION_ACTIVE:
case EC_FLASH_REGION_WP_RO:
entry = &ec->ec_config.region[req->region];
resp->offset = entry->offset;
resp->size = entry->length;
len = sizeof(*resp);
printf("EC flash region %d: offset=%#x, size=%#x\n",
req->region, resp->offset, resp->size);
break;
default:
printf("** Unknown flash region %d\n", req->region);
return -1;
}
break;
}
case EC_CMD_FLASH_ERASE: {
const struct ec_params_flash_erase *req = req_data;
memset(ec->flash_data + req->offset,
ec->ec_config.flash_erase_value,
req->size);
len = 0;
break;
}
case EC_CMD_FLASH_WRITE: {
const struct ec_params_flash_write *req = req_data;
memcpy(ec->flash_data + req->offset, req + 1, req->size);
len = 0;
break;
}
case EC_CMD_MKBP_STATE:
len = cros_ec_keyscan(ec, resp_data);
break;
case EC_CMD_ENTERING_MODE:
len = 0;
break;
default:
printf(" ** Unknown EC command %#02x\n", req_hdr->command);
return -1;
}
return len;
}
int cros_ec_sandbox_packet(struct udevice *udev, int out_bytes, int in_bytes)
{
struct cros_ec_dev *dev = dev_get_uclass_priv(udev);
struct ec_state *ec = dev_get_priv(dev->dev);
struct ec_host_request *req_hdr = (struct ec_host_request *)dev->dout;
const void *req_data = req_hdr + 1;
struct ec_host_response *resp_hdr = (struct ec_host_response *)dev->din;
void *resp_data = resp_hdr + 1;
int len;
len = process_cmd(ec, req_hdr, req_data, resp_hdr, resp_data);
if (len < 0)
return len;
resp_hdr->struct_version = 3;
resp_hdr->result = EC_RES_SUCCESS;
resp_hdr->data_len = len;
resp_hdr->reserved = 0;
len += sizeof(*resp_hdr);
resp_hdr->checksum = 0;
resp_hdr->checksum = (uint8_t)
-cros_ec_calc_checksum((const uint8_t *)resp_hdr, len);
return in_bytes;
}
void cros_ec_check_keyboard(struct udevice *dev)
{
struct ec_state *ec = dev_get_priv(dev);
ulong start;
printf("Press keys for EC to detect on reset (ESC=recovery)...");
start = get_timer(0);
while (get_timer(start) < 1000)
;
putc('\n');
if (!sandbox_sdl_key_pressed(KEY_ESC)) {
ec->recovery_req = true;
printf(" - EC requests recovery\n");
}
}
int cros_ec_probe(struct udevice *dev)
{
struct ec_state *ec = dev->priv;
struct cros_ec_dev *cdev = dev->uclass_priv;
struct udevice *keyb_dev;
ofnode node;
int err;
memcpy(ec, &s_state, sizeof(*ec));
err = cros_ec_decode_ec_flash(dev, &ec->ec_config);
if (err) {
debug("%s: Cannot device EC flash\n", __func__);
return err;
}
node = ofnode_null();
for (device_find_first_child(dev, &keyb_dev);
keyb_dev;
device_find_next_child(&keyb_dev)) {
if (device_get_uclass_id(keyb_dev) == UCLASS_KEYBOARD) {
node = dev_ofnode(keyb_dev);
break;
}
}
if (!ofnode_valid(node)) {
debug("%s: No cros_ec keyboard found\n", __func__);
} else if (keyscan_read_fdt_matrix(ec, node)) {
debug("%s: Could not read key matrix\n", __func__);
return -1;
}
/* If we loaded EC data, check that the length matches */
if (ec->flash_data &&
ec->flash_data_len != ec->ec_config.flash.length) {
printf("EC data length is %x, expected %x, discarding data\n",
ec->flash_data_len, ec->ec_config.flash.length);
os_free(ec->flash_data);
ec->flash_data = NULL;
}
/* Otherwise allocate the memory */
if (!ec->flash_data) {
ec->flash_data_len = ec->ec_config.flash.length;
ec->flash_data = os_malloc(ec->flash_data_len);
if (!ec->flash_data)
return -ENOMEM;
}
cdev->dev = dev;
g_state = ec;
return cros_ec_register(dev);
}
struct dm_cros_ec_ops cros_ec_ops = {
.packet = cros_ec_sandbox_packet,
};
static const struct udevice_id cros_ec_ids[] = {
{ .compatible = "google,cros-ec-sandbox" },
{ }
};
U_BOOT_DRIVER(cros_ec_sandbox) = {
.name = "cros_ec_sandbox",
.id = UCLASS_CROS_EC,
.of_match = cros_ec_ids,
.probe = cros_ec_probe,
.priv_auto_alloc_size = sizeof(struct ec_state),
.ops = &cros_ec_ops,
};