lib/tpm-utils.h

   1 /* SPDX-License-Identifier: GPL-2.0+ */
   2 /*
   3  * Copyright (c) 2013 The Chromium OS Authors.
   4  * Coypright (c) 2013 Guntermann & Drunck GmbH
   5  */
   6
   7 #ifndef __TPM_UTILS_H
   8 #define __TPM_UTILS_H
   9
  10 #define COMMAND_BUFFER_SIZE 256
  11
  12 /* Internal error of TPM command library */
  13 #define TPM_LIB_ERROR ((u32)~0u)
  14
  15 /* To make strings of commands more easily */
  16 #define __MSB(x) ((x) >> 8)
  17 #define __LSB(x) ((x) & 0xFF)
  18 #define tpm_u16(x) __MSB(x), __LSB(x)
  19 #define tpm_u32(x) tpm_u16((x) >> 16), tpm_u16((x) & 0xFFFF)
  20
  21 /**
  22  * Pack data into a byte string.  The data types are specified in
  23  * the format string: 'b' means unsigned byte, 'w' unsigned word,
  24  * 'd' unsigned double word, and 's' byte string.  The data are a
  25  * series of offsets and values (for type byte string there are also
  26  * lengths).  The data values are packed into the byte string
  27  * sequentially, and so a latter value could over-write a former
  28  * value.
  29  *
  30  * @param str           output string
  31  * @param size          size of output string
  32  * @param format        format string
  33  * @param ...           data points
  34  * @return 0 on success, non-0 on error
  35  */
  36 int pack_byte_string(u8 *str, size_t size, const char *format, ...);
  37
  38 /**
  39  * Unpack data from a byte string.  The data types are specified in
  40  * the format string: 'b' means unsigned byte, 'w' unsigned word,
  41  * 'd' unsigned double word, and 's' byte string.  The data are a
  42  * series of offsets and pointers (for type byte string there are also
  43  * lengths).
  44  *
  45  * @param str           output string
  46  * @param size          size of output string
  47  * @param format        format string
  48  * @param ...           data points
  49  * @return 0 on success, non-0 on error
  50  */
  51 int unpack_byte_string(const u8 *str, size_t size, const char *format, ...);
  52
  53 /**
  54  * Get TPM command size.
  55  *
  56  * @param command       byte string of TPM command
  57  * @return command size of the TPM command
  58  */
  59 u32 tpm_command_size(const void *command);
  60
  61 /**
  62  * Get TPM response return code, which is one of TPM_RESULT values.
  63  *
  64  * @param response      byte string of TPM response
  65  * @return return code of the TPM response
  66  */
  67 u32 tpm_return_code(const void *response);
  68
  69 /**
  70  * Send a TPM command and return response's return code, and optionally
  71  * return response to caller.
  72  *
  73  * @param command       byte string of TPM command
  74  * @param response      output buffer for TPM response, or NULL if the
  75  *                      caller does not care about it
  76  * @param size_ptr      output buffer size (input parameter) and TPM
  77  *                      response length (output parameter); this parameter
  78  *                      is a bidirectional
  79  * @return return code of the TPM response
  80  */
  81 u32 tpm_sendrecv_command(struct udevice *dev, const void *command,
  82                          void *response, size_t *size_ptr);
  83
  84 #endif /* __TPM_UTILS_H */