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Diffstat (limited to 'src/drivers/vpd/lib_vpd.h')
| -rw-r--r-- | src/drivers/vpd/lib_vpd.h | 226 |
1 files changed, 226 insertions, 0 deletions
diff --git a/src/drivers/vpd/lib_vpd.h b/src/drivers/vpd/lib_vpd.h new file mode 100644 index 0000000000..7a7566b234 --- /dev/null +++ b/src/drivers/vpd/lib_vpd.h @@ -0,0 +1,226 @@ +/* + * Copyright (c) 2013 The Chromium OS Authors. All rights reserved. + * Use of this source code is governed by a BSD-style license that can be + * found in the LICENSE file. + * + */ + +#ifndef __LIB_VPD__ +#define __LIB_VPD__ + +#include <inttypes.h> + +enum { + VPD_OK = 0, + VPD_FAIL, +}; + +enum { + VPD_TYPE_TERMINATOR = 0, + VPD_TYPE_STRING, + VPD_TYPE_INFO = 0xfe, + VPD_TYPE_IMPLICIT_TERMINATOR = 0xff, +}; + +enum { + VPD_AS_LONG_AS = -1, +}; + +enum { /* export_type */ + VPD_EXPORT_KEY_VALUE = 1, + VPD_EXPORT_VALUE, + VPD_EXPORT_AS_PARAMETER, +}; + +/* Callback for decodeVpdString to invoke. */ +typedef int VpdDecodeCallback(const uint8_t *key, int32_t key_len, + const uint8_t *value, int32_t value_len, + void *arg); + +/* Container data types */ +struct StringPair { + uint8_t *key; + uint8_t *value; + int pad_len; + int filter_out; /* TRUE means not exported. */ + struct StringPair *next; +}; + +struct PairContainer { + struct StringPair *first; +}; + + +/*********************************************************************** + * Encode and decode VPD entries + ***********************************************************************/ + +/* Encodes the len into multiple bytes with the following format. + * + * 7 6 ............ 0 + * +----+------------------+ + * |More| Length | ... + * +----+------------------+ + * + * The encode_buf points to the actual position we are going to store. + * encoded_len will return the exact bytes we encoded in this function. + * Returns fail if the buffer is not long enough. + */ +int encodeLen( + const int32_t len, + uint8_t *encode_buf, + const int32_t max_len, + int32_t *encoded_len); + +/* Given an encoded string, this functions decodes the length field which varies + * from 1 byte to many bytes. + * + * The in points the actual byte going to be decoded. The *length returns + * the decoded length field. The number of consumed bytes will be stroed in + * decoded_len. + * + * Returns VPD_FAIL if more bit is 1, but actually reaches the end of string. + */ +int decodeLen( + const int32_t max_len, + const uint8_t *in, + int32_t *length, + int32_t *decoded_len); + + +/* Encodes the terminator. + * When calling, the output_buf should point to the start of buffer while + * *generated_len should contain how many bytes exist in buffer now. + * After return, *generated_len would be plused the number of bytes generated + * in this function. + */ +int encodeVpdTerminator( + const int max_buffer_len, + uint8_t *output_buf, + int *generated_len); + +/* Encodes the given type/key/value pair into buffer. + * + * The pad_value_len is used to control the output value length. + * When pad_value_len > 0, the value is outputted into fixed length (pad \0 + * if the value is shorter). Truncated if too long. + * pad_value_len == VPD_NO_LIMIT, output the value as long as possible. + * This is useful when we want to fix the structure layout at beginning. + * + * The encoded string will be stored in output_buf. If it is longer than + * max_buffer_len, this function returns fail. If the buffer is long enough, + * the generated_len will be updated. + * + * When calling, the output_buf should point to the start of buffer while + * *generated_len should contain how many bytes exist in buffer now. + * After return, *generated_len would be plused the number of bytes generated + * in this function. + * + * The initial value of *generated_len can be non-zero, so that this value + * can be used between multiple calls to encodeVpd2Pair(). + */ +int encodeVpdString( + const uint8_t *key, + const uint8_t *value, + const int pad_value_len, + const int max_buffer_len, + uint8_t *output_buf, + int *generated_len); + + +/* Given the encoded string, this function invokes callback with extracted + * (key, value). The *consumed will be plused the number of bytes consumed in + * this function. + * + * The input_buf points to the first byte of the input buffer. + * + * The *consumed starts from 0, which is actually the next byte to be decoded. + * It can be non-zero to be used in multiple calls. + * + * If one entry is successfully decoded, sends it to callback and returns the + * result. + */ +int decodeVpdString( + const int32_t max_len, + const uint8_t *input_buf, + int32_t *consumed, + VpdDecodeCallback callback, + void *callback_arg); + +/*********************************************************************** + * Container helpers + ***********************************************************************/ +void initContainer(struct PairContainer *container); + +struct StringPair *findString(struct PairContainer *container, + const uint8_t *key, + struct StringPair ***prev_next); + +/* If key is already existed in container, its value will be replaced. + * If not existed, creates new entry in container. + */ +void setString(struct PairContainer *container, + const uint8_t *key, + const uint8_t *value, + const int pad_len); + +/* merge all entries in src into dst. If key is duplicate, overwrite it. + */ +void mergeContainer(struct PairContainer *dst, + const struct PairContainer *src); + +/* subtract src from dst. +*/ +int subtractContainer(struct PairContainer *dst, + const struct PairContainer *src); + +/* Given a container, encode its all entries into the buffer. + */ +int encodeContainer(const struct PairContainer *container, + const int max_buf_len, + uint8_t *buf, + int *generated); + +/* Given a VPD blob, decode its entries and push into container. + */ +int decodeToContainer(struct PairContainer *container, + const int32_t max_len, + const uint8_t *input_buf, + int32_t *consumed); + +/* Set filter for exporting functions. + * If filter is NULL, resets the filter so that everything can be exported. + */ +int setContainerFilter(struct PairContainer *container, + const uint8_t *filter); + +/* + * Remove a key. + * Returns VPD_OK if deleted successfully. Otherwise, VPD_FAIL. + */ +int deleteKey(struct PairContainer *container, + const uint8_t *key); + +/* + * Returns number of pairs in container. + */ +int lenOfContainer(const struct PairContainer *container); + +/* + * Export the container content with human-readable text. + * + * The buf points to the first byte of buffer and *generated contains the number + * of bytes already existed in buffer. + * + * Afterward, the *generated will be plused on exact bytes this function has + * generated. + */ +int exportContainer(const int export_type, + const struct PairContainer *container, + const int max_buf_len, + uint8_t *buf, + int *generated); + +void destroyContainer(struct PairContainer *container); + +#endif /* __LIB_VPD__ */ |