u-boot/lib/tpm-utils.h
Miquel Raynal f6872816ce tpm: add macros to enhance TPM commands readability
TPM commands are much easier to read/write with these macros that will
transform words or integers into byte strings. This way, there is no
need to call pack_byte_string() while all variable length in a command
are known (and at must 4 bytes, which is a lot of them).

Signed-off-by: Miquel Raynal <miquel.raynal@bootlin.com>
Reviewed-by: Simon Glass <sjg@chromium.org>
Reviewed-by: Tom Rini <trini@konsulko.com>
2018-05-25 20:12:56 -04:00

101 lines
3 KiB
C

/* SPDX-License-Identifier: GPL-2.0+ */
/*
* Copyright (c) 2013 The Chromium OS Authors.
* Coypright (c) 2013 Guntermann & Drunck GmbH
*/
#ifndef __TPM_UTILS_H
#define __TPM_UTILS_H
#define COMMAND_BUFFER_SIZE 256
/* Internal error of TPM command library */
#define TPM_LIB_ERROR ((u32)~0u)
/* To make strings of commands more easily */
#define __MSB(x) ((x) >> 8)
#define __LSB(x) ((x) & 0xFF)
#define tpm_u16(x) __MSB(x), __LSB(x)
#define tpm_u32(x) tpm_u16((x) >> 16), tpm_u16((x) & 0xFFFF)
/**
* tpm_open() - Request access to locality 0 for the caller
*
* After all commands have been completed the caller is supposed to
* call tpm_close().
*
* Returns 0 on success, -ve on failure.
*/
int tpm_open(struct udevice *dev);
/**
* tpm_close() - Close the current session
*
* Releasing the locked locality. Returns 0 on success, -ve 1 on
* failure (in case lock removal did not succeed).
*/
int tpm_close(struct udevice *dev);
/**
* Pack data into a byte string. The data types are specified in
* the format string: 'b' means unsigned byte, 'w' unsigned word,
* 'd' unsigned double word, and 's' byte string. The data are a
* series of offsets and values (for type byte string there are also
* lengths). The data values are packed into the byte string
* sequentially, and so a latter value could over-write a former
* value.
*
* @param str output string
* @param size size of output string
* @param format format string
* @param ... data points
* @return 0 on success, non-0 on error
*/
int pack_byte_string(u8 *str, size_t size, const char *format, ...);
/**
* Unpack data from a byte string. The data types are specified in
* the format string: 'b' means unsigned byte, 'w' unsigned word,
* 'd' unsigned double word, and 's' byte string. The data are a
* series of offsets and pointers (for type byte string there are also
* lengths).
*
* @param str output string
* @param size size of output string
* @param format format string
* @param ... data points
* @return 0 on success, non-0 on error
*/
int unpack_byte_string(const u8 *str, size_t size, const char *format, ...);
/**
* Get TPM command size.
*
* @param command byte string of TPM command
* @return command size of the TPM command
*/
u32 tpm_command_size(const void *command);
/**
* Get TPM response return code, which is one of TPM_RESULT values.
*
* @param response byte string of TPM response
* @return return code of the TPM response
*/
u32 tpm_return_code(const void *response);
/**
* Send a TPM command and return response's return code, and optionally
* return response to caller.
*
* @param command byte string of TPM command
* @param response output buffer for TPM response, or NULL if the
* caller does not care about it
* @param size_ptr output buffer size (input parameter) and TPM
* response length (output parameter); this parameter
* is a bidirectional
* @return return code of the TPM response
*/
u32 tpm_sendrecv_command(const void *command, void *response, size_t *size_ptr);
#endif /* __TPM_UTILS_H */