Add a simple emulation of the Chrome OS EC for sandbox, so that it can perform various EC tasks such as keyboard handling. Reviewed-by: Vadim Bendebury <vbendeb@chromium.org> Signed-off-by: Simon Glass <sjg@chromium.org>master
Simon Glass
11 years ago
parent
2ab83f0d75
commit
df93d90aea
@ -0,0 +1,559 @@ |
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/*
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* Chromium OS cros_ec driver - sandbox emulation |
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* |
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* Copyright (c) 2013 The Chromium OS Authors. |
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* |
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* SPDX-License-Identifier: GPL-2.0+ |
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*/ |
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#include <common.h> |
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#include <cros_ec.h> |
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#include <ec_commands.h> |
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#include <errno.h> |
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#include <hash.h> |
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#include <malloc.h> |
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#include <os.h> |
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#include <sha256.h> |
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#include <spi.h> |
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#include <asm/state.h> |
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#include <asm/sdl.h> |
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#include <linux/input.h> |
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/*
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* Ultimately it shold be possible to connect an Chrome OS EC emulation |
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* to U-Boot and remove all of this code. But this provides a test |
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* environment for bringing up chromeos_sandbox and demonstrating its |
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* utility. |
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* |
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* This emulation includes the following: |
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* |
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* 1. Emulation of the keyboard, by converting keypresses received from SDL |
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* into key scan data, passed back from the EC as key scan messages. The |
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* key layout is read from the device tree. |
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* |
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* 2. Emulation of vboot context - so this can be read/written as required. |
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* |
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* 3. Save/restore of EC state, so that the vboot context, flash memory |
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* contents and current image can be preserved across boots. This is important |
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* since the EC is supposed to continue running even if the AP resets. |
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* |
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* 4. Some event support, in particular allowing Escape to be pressed on boot |
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* to enter recovery mode. The EC passes this to U-Boot through the normal |
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* event message. |
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* |
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* 5. Flash read/write/erase support, so that software sync works. The |
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* protect messages are supported but no protection is implemented. |
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* |
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* 6. Hashing of the EC image, again to support software sync. |
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* |
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* Other features can be added, although a better path is probably to link |
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* the EC image in with U-Boot (Vic has demonstrated a prototype for this). |
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*/ |
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DECLARE_GLOBAL_DATA_PTR; |
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#define KEYBOARD_ROWS 8 |
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#define KEYBOARD_COLS 13 |
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/* A single entry of the key matrix */ |
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struct ec_keymatrix_entry { |
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int row; /* key matrix row */ |
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int col; /* key matrix column */ |
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int keycode; /* corresponding linux key code */ |
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}; |
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/**
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* struct ec_state - Information about the EC state |
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* |
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* @vbnv_context: Vboot context data stored by EC |
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* @ec_config: FDT config information about the EC (e.g. flashmap) |
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* @flash_data: Contents of flash memory |
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* @flash_data_len: Size of flash memory |
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* @current_image: Current image the EC is running |
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* @matrix_count: Number of keys to decode in matrix |
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* @matrix: Information about keyboard matrix |
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* @keyscan: Current keyscan information (bit set for each row/column pressed) |
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* @recovery_req: Keyboard recovery requested |
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*/ |
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struct ec_state { |
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uint8_t vbnv_context[EC_VBNV_BLOCK_SIZE]; |
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struct fdt_cros_ec ec_config; |
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uint8_t *flash_data; |
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int flash_data_len; |
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enum ec_current_image current_image; |
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int matrix_count; |
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struct ec_keymatrix_entry *matrix; /* the key matrix info */ |
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uint8_t keyscan[KEYBOARD_COLS]; |
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bool recovery_req; |
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} s_state, *state; |
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/**
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* cros_ec_read_state() - read the sandbox EC state from the state file |
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* |
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* If data is available, then blob and node will provide access to it. If |
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* not this function sets up an empty EC. |
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* |
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* @param blob: Pointer to device tree blob, or NULL if no data to read |
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* @param node: Node offset to read from |
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*/ |
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static int cros_ec_read_state(const void *blob, int node) |
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{ |
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struct ec_state *ec = &s_state; |
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const char *prop; |
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int len; |
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/* Set everything to defaults */ |
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ec->current_image = EC_IMAGE_RO; |
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if (!blob) |
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return 0; |
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/* Read the data if available */ |
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ec->current_image = fdtdec_get_int(blob, node, "current-image", |
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EC_IMAGE_RO); |
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prop = fdt_getprop(blob, node, "vbnv-context", &len); |
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if (prop && len == sizeof(ec->vbnv_context)) |
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memcpy(ec->vbnv_context, prop, len); |
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prop = fdt_getprop(blob, node, "flash-data", &len); |
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if (prop) { |
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ec->flash_data_len = len; |
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ec->flash_data = os_malloc(len); |
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if (!ec->flash_data) |
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return -ENOMEM; |
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memcpy(ec->flash_data, prop, len); |
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debug("%s: Loaded EC flash data size %#x\n", __func__, len); |
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} |
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return 0; |
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} |
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/**
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* cros_ec_write_state() - Write out our state to the state file |
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* |
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* The caller will ensure that there is a node ready for the state. The node |
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* may already contain the old state, in which case it is overridden. |
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* |
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* @param blob: Device tree blob holding state |
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* @param node: Node to write our state into |
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*/ |
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static int cros_ec_write_state(void *blob, int node) |
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{ |
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struct ec_state *ec = &s_state; |
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/* We are guaranteed enough space to write basic properties */ |
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fdt_setprop_u32(blob, node, "current-image", ec->current_image); |
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fdt_setprop(blob, node, "vbnv-context", ec->vbnv_context, |
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sizeof(ec->vbnv_context)); |
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return state_setprop(node, "flash-data", ec->flash_data, |
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ec->ec_config.flash.length); |
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} |
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SANDBOX_STATE_IO(cros_ec, "google,cros-ec", cros_ec_read_state, |
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cros_ec_write_state); |
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/**
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* Return the number of bytes used in the specified image. |
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* |
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* This is the actual size of code+data in the image, as opposed to the |
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* amount of space reserved in flash for that image. This code is similar to |
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* that used by the real EC code base. |
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* |
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* @param ec Current emulated EC state |
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* @param entry Flash map entry containing the image to check |
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* @return actual image size in bytes, 0 if the image contains no content or |
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* error. |
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*/ |
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static int get_image_used(struct ec_state *ec, struct fmap_entry *entry) |
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{ |
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int size; |
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/*
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* Scan backwards looking for 0xea byte, which is by definition the |
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* last byte of the image. See ec.lds.S for how this is inserted at |
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* the end of the image. |
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*/ |
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for (size = entry->length - 1; |
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size > 0 && ec->flash_data[entry->offset + size] != 0xea; |
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size--) |
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; |
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return size ? size + 1 : 0; /* 0xea byte IS part of the image */ |
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} |
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/**
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* Read the key matrix from the device tree |
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* |
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* Keymap entries in the fdt take the form of 0xRRCCKKKK where |
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* RR=Row CC=Column KKKK=Key Code |
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* |
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* @param ec Current emulated EC state |
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* @param blob Device tree blob containing keyscan information |
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* @param node Keyboard node of device tree containing keyscan information |
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* @return 0 if ok, -1 on error |
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*/ |
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static int keyscan_read_fdt_matrix(struct ec_state *ec, const void *blob, |
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int node) |
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{ |
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const u32 *cell; |
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int upto; |
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int len; |
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cell = fdt_getprop(blob, node, "linux,keymap", &len); |
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ec->matrix_count = len / 4; |
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ec->matrix = calloc(ec->matrix_count, sizeof(*ec->matrix)); |
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if (!ec->matrix) { |
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debug("%s: Out of memory for key matrix\n", __func__); |
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return -1; |
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} |
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/* Now read the data */ |
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for (upto = 0; upto < ec->matrix_count; upto++) { |
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struct ec_keymatrix_entry *matrix = &ec->matrix[upto]; |
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u32 word; |
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word = fdt32_to_cpu(*cell++); |
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matrix->row = word >> 24; |
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matrix->col = (word >> 16) & 0xff; |
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matrix->keycode = word & 0xffff; |
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/* Hard-code some sanity limits for now */ |
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if (matrix->row >= KEYBOARD_ROWS || |
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matrix->col >= KEYBOARD_COLS) { |
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debug("%s: Matrix pos out of range (%d,%d)\n", |
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__func__, matrix->row, matrix->col); |
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return -1; |
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} |
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} |
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if (upto != ec->matrix_count) { |
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debug("%s: Read mismatch from key matrix\n", __func__); |
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return -1; |
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} |
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return 0; |
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} |
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/**
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* Return the next keyscan message contents |
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* |
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* @param ec Current emulated EC state |
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* @param scan Place to put keyscan bytes for the keyscan message (must hold |
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* enough space for a full keyscan) |
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* @return number of bytes of valid scan data |
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*/ |
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static int cros_ec_keyscan(struct ec_state *ec, uint8_t *scan) |
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{ |
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const struct ec_keymatrix_entry *matrix; |
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int bytes = KEYBOARD_COLS; |
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int key[8]; /* allow up to 8 keys to be pressed at once */ |
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int count; |
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int i; |
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memset(ec->keyscan, '\0', bytes); |
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count = sandbox_sdl_scan_keys(key, ARRAY_SIZE(key)); |
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/* Look up keycode in matrix */ |
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for (i = 0, matrix = ec->matrix; i < ec->matrix_count; i++, matrix++) { |
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bool found; |
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int j; |
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for (found = false, j = 0; j < count; j++) { |
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if (matrix->keycode == key[j]) |
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found = true; |
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} |
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if (found) { |
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debug("%d: %d,%d\n", matrix->keycode, matrix->row, |
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matrix->col); |
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ec->keyscan[matrix->col] |= 1 << matrix->row; |
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} |
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} |
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memcpy(scan, ec->keyscan, bytes); |
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return bytes; |
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} |
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/**
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* Process an emulated EC command |
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* |
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* @param ec Current emulated EC state |
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* @param req_hdr Pointer to request header |
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* @param req_data Pointer to body of request |
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* @param resp_hdr Pointer to place to put response header |
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* @param resp_data Pointer to place to put response data, if any |
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* @return length of response data, or 0 for no response data, or -1 on error |
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*/ |
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static int process_cmd(struct ec_state *ec, |
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struct ec_host_request *req_hdr, const void *req_data, |
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struct ec_host_response *resp_hdr, void *resp_data) |
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{ |
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int len; |
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/* TODO(sjg@chromium.org): Check checksums */ |
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debug("EC command %#0x\n", req_hdr->command); |
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switch (req_hdr->command) { |
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case EC_CMD_HELLO: { |
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const struct ec_params_hello *req = req_data; |
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struct ec_response_hello *resp = resp_data; |
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resp->out_data = req->in_data + 0x01020304; |
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len = sizeof(*resp); |
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break; |
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} |
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case EC_CMD_GET_VERSION: { |
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struct ec_response_get_version *resp = resp_data; |
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strcpy(resp->version_string_ro, "sandbox_ro"); |
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strcpy(resp->version_string_rw, "sandbox_rw"); |
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resp->current_image = ec->current_image; |
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debug("Current image %d\n", resp->current_image); |
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len = sizeof(*resp); |
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break; |
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} |
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case EC_CMD_VBNV_CONTEXT: { |
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const struct ec_params_vbnvcontext *req = req_data; |
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struct ec_response_vbnvcontext *resp = resp_data; |
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switch (req->op) { |
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case EC_VBNV_CONTEXT_OP_READ: |
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memcpy(resp->block, ec->vbnv_context, |
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sizeof(resp->block)); |
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len = sizeof(*resp); |
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break; |
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case EC_VBNV_CONTEXT_OP_WRITE: |
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memcpy(ec->vbnv_context, resp->block, |
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sizeof(resp->block)); |
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len = 0; |
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break; |
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default: |
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printf(" ** Unknown vbnv_context command %#02x\n", |
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req->op); |
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return -1; |
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} |
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break; |
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} |
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case EC_CMD_REBOOT_EC: { |
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const struct ec_params_reboot_ec *req = req_data; |
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printf("Request reboot type %d\n", req->cmd); |
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switch (req->cmd) { |
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case EC_REBOOT_DISABLE_JUMP: |
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len = 0; |
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break; |
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case EC_REBOOT_JUMP_RW: |
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ec->current_image = EC_IMAGE_RW; |
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len = 0; |
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break; |
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default: |
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puts(" ** Unknown type"); |
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return -1; |
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} |
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break; |
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} |
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case EC_CMD_HOST_EVENT_GET_B: { |
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struct ec_response_host_event_mask *resp = resp_data; |
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resp->mask = 0; |
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if (ec->recovery_req) { |
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resp->mask |= EC_HOST_EVENT_MASK( |
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EC_HOST_EVENT_KEYBOARD_RECOVERY); |
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} |
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len = sizeof(*resp); |
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break; |
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} |
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case EC_CMD_VBOOT_HASH: { |
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const struct ec_params_vboot_hash *req = req_data; |
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struct ec_response_vboot_hash *resp = resp_data; |
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struct fmap_entry *entry; |
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int ret, size; |
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entry = &state->ec_config.region[EC_FLASH_REGION_RW]; |
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switch (req->cmd) { |
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case EC_VBOOT_HASH_RECALC: |
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case EC_VBOOT_HASH_GET: |
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size = SHA256_SUM_LEN; |
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len = get_image_used(ec, entry); |
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ret = hash_block("sha256", |
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ec->flash_data + entry->offset, |
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len, resp->hash_digest, &size); |
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if (ret) { |
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printf(" ** hash_block() failed\n"); |
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return -1; |
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} |
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resp->status = EC_VBOOT_HASH_STATUS_DONE; |
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resp->hash_type = EC_VBOOT_HASH_TYPE_SHA256; |
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resp->digest_size = size; |
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resp->reserved0 = 0; |
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resp->offset = entry->offset; |
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resp->size = len; |
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len = sizeof(*resp); |
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break; |
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default: |
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printf(" ** EC_CMD_VBOOT_HASH: Unknown command %d\n", |
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req->cmd); |
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return -1; |
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} |
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break; |
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} |
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case EC_CMD_FLASH_PROTECT: { |
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const struct ec_params_flash_protect *req = req_data; |
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struct ec_response_flash_protect *resp = resp_data; |
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uint32_t expect = EC_FLASH_PROTECT_ALL_NOW | |
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EC_FLASH_PROTECT_ALL_AT_BOOT; |
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printf("mask=%#x, flags=%#x\n", req->mask, req->flags); |
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if (req->flags == expect || req->flags == 0) { |
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resp->flags = req->flags ? EC_FLASH_PROTECT_ALL_NOW : |
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0; |
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resp->valid_flags = EC_FLASH_PROTECT_ALL_NOW; |
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resp->writable_flags = 0; |
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len = sizeof(*resp); |
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} else { |
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puts(" ** unexpected flash protect request\n"); |
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return -1; |
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} |
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break; |
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} |
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case EC_CMD_FLASH_REGION_INFO: { |
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const struct ec_params_flash_region_info *req = req_data; |
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struct ec_response_flash_region_info *resp = resp_data; |
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struct fmap_entry *entry; |
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switch (req->region) { |
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case EC_FLASH_REGION_RO: |
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case EC_FLASH_REGION_RW: |
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case EC_FLASH_REGION_WP_RO: |
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entry = &state->ec_config.region[req->region]; |
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resp->offset = entry->offset; |
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resp->size = entry->length; |
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len = sizeof(*resp); |
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printf("EC flash region %d: offset=%#x, size=%#x\n", |
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req->region, resp->offset, resp->size); |
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break; |
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default: |
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printf("** Unknown flash region %d\n", req->region); |
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return -1; |
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} |
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break; |
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} |
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case EC_CMD_FLASH_ERASE: { |
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const struct ec_params_flash_erase *req = req_data; |
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memset(ec->flash_data + req->offset, |
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ec->ec_config.flash_erase_value, |
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req->size); |
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len = 0; |
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break; |
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} |
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case EC_CMD_FLASH_WRITE: { |
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const struct ec_params_flash_write *req = req_data; |
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memcpy(ec->flash_data + req->offset, req + 1, req->size); |
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len = 0; |
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break; |
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} |
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case EC_CMD_MKBP_STATE: |
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len = cros_ec_keyscan(ec, resp_data); |
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break; |
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default: |
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printf(" ** Unknown EC command %#02x\n", req_hdr->command); |
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return -1; |
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} |
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return len; |
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} |
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int cros_ec_sandbox_packet(struct cros_ec_dev *dev, int out_bytes, |
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int in_bytes) |
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{ |
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struct ec_host_request *req_hdr = (struct ec_host_request *)dev->dout; |
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const void *req_data = req_hdr + 1; |
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struct ec_host_response *resp_hdr = (struct ec_host_response *)dev->din; |
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void *resp_data = resp_hdr + 1; |
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int len; |
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len = process_cmd(&s_state, req_hdr, req_data, resp_hdr, resp_data); |
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if (len < 0) |
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return len; |
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resp_hdr->struct_version = 3; |
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resp_hdr->result = EC_RES_SUCCESS; |
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resp_hdr->data_len = len; |
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resp_hdr->reserved = 0; |
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len += sizeof(*resp_hdr); |
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resp_hdr->checksum = 0; |
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resp_hdr->checksum = (uint8_t) |
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-cros_ec_calc_checksum((const uint8_t *)resp_hdr, len); |
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return in_bytes; |
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} |
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int cros_ec_sandbox_decode_fdt(struct cros_ec_dev *dev, const void *blob) |
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{ |
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return 0; |
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} |
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void cros_ec_check_keyboard(struct cros_ec_dev *dev) |
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{ |
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struct ec_state *ec = &s_state; |
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ulong start; |
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printf("Press keys for EC to detect on reset (ESC=recovery)..."); |
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start = get_timer(0); |
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while (get_timer(start) < 1000) |
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; |
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putc('\n'); |
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if (!sandbox_sdl_key_pressed(KEY_ESC)) { |
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ec->recovery_req = true; |
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printf(" - EC requests recovery\n"); |
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} |
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} |
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/**
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* Initialize sandbox EC emulation. |
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* |
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* @param dev CROS_EC device |
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* @param blob Device tree blob |
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* @return 0 if ok, -1 on error |
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*/ |
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int cros_ec_sandbox_init(struct cros_ec_dev *dev, const void *blob) |
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{ |
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struct ec_state *ec = &s_state; |
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int node; |
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int err; |
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state = &s_state; |
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err = cros_ec_decode_ec_flash(blob, &ec->ec_config); |
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if (err) |
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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; |
||||
} |
||||
Loading…
Reference in new issue