diff options
Diffstat (limited to 'roms/u-boot/drivers/misc/cros_ec_sandbox.c')
| -rw-r--r-- | roms/u-boot/drivers/misc/cros_ec_sandbox.c | 559 |
1 files changed, 559 insertions, 0 deletions
diff --git a/roms/u-boot/drivers/misc/cros_ec_sandbox.c b/roms/u-boot/drivers/misc/cros_ec_sandbox.c new file mode 100644 index 00000000..4bb1d60e --- /dev/null +++ b/roms/u-boot/drivers/misc/cros_ec_sandbox.c @@ -0,0 +1,559 @@ +/* + * Chromium OS cros_ec driver - sandbox emulation + * + * Copyright (c) 2013 The Chromium OS Authors. + * + * SPDX-License-Identifier: GPL-2.0+ + */ + +#include <common.h> +#include <cros_ec.h> +#include <ec_commands.h> +#include <errno.h> +#include <hash.h> +#include <malloc.h> +#include <os.h> +#include <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). + */ + +DECLARE_GLOBAL_DATA_PTR; + +#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 { + uint8_t vbnv_context[EC_VBNV_BLOCK_SIZE]; + 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, *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 = &s_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 blob Device tree blob containing keyscan information + * @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, const void *blob, + int node) +{ + const u32 *cell; + int upto; + int len; + + cell = fdt_getprop(blob, 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 = &state->ec_config.region[EC_FLASH_REGION_RW]; + + 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_RW: + case EC_FLASH_REGION_WP_RO: + entry = &state->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; + default: + printf(" ** Unknown EC command %#02x\n", req_hdr->command); + return -1; + } + + return len; +} + +int cros_ec_sandbox_packet(struct cros_ec_dev *dev, int out_bytes, + int in_bytes) +{ + 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(&s_state, 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; +} + +int cros_ec_sandbox_decode_fdt(struct cros_ec_dev *dev, const void *blob) +{ + return 0; +} + +void cros_ec_check_keyboard(struct cros_ec_dev *dev) +{ + struct ec_state *ec = &s_state; + 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"); + } +} + +/** + * Initialize sandbox EC emulation. + * + * @param dev CROS_EC device + * @param blob Device tree blob + * @return 0 if ok, -1 on error + */ +int cros_ec_sandbox_init(struct cros_ec_dev *dev, const void *blob) +{ + struct ec_state *ec = &s_state; + int node; + int err; + + state = &s_state; + err = cros_ec_decode_ec_flash(blob, &ec->ec_config); + if (err) + return err; + + node = fdtdec_next_compatible(blob, 0, COMPAT_GOOGLE_CROS_EC_KEYB); + if (node < 0) { + debug("%s: No cros_ec keyboard found\n", __func__); + } else if (keyscan_read_fdt_matrix(ec, blob, 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; + } + + return 0; +} |