tpm_nvread reads data from an NVRAM area and either displays them or writes them into a file. The user must provide the index of the NVRAM area. If the user provided the number of bytes to read then this will be the maximum number of bytes that will be read from the NVRAM area, otherwise the whole NVRAM area will be read. Some NVRAM areas only allow read sizes of zero, i.e., NVRAM area with index 0. Optionally an offset into the NVRAM area can be given where the reading of the data is to start. If the NVRAM area has permission bits set that require owner or NVRAM area authentication, then the password must be provided via the password option.
The following options are supported:
- -h, --help
Display command usage info.
- -v, --version
Display command version info.
- -l, --log [none|error|info|debug]
Set logging level.
- -u, --unicode
Use TSS UNICODE encoding for passwords to comply with applications using TSS popup boxes
- -z, --well-known
Use a secret of all zeros (20 bytes of zeros) as either the NVRAM area or owner secret.
- -p, --password
Depending on what type of authentication is required for the NVRAM area, this must either be the NVRAM area or owner password.
A password may be directly provided for example by using '--password=password' or '-ppassword'. If no password is provided then the program will prompt the user for the password.
- -i, --index
The index of the NVRAM area. The parameter may either be a decimal number or a hexadecimal number starting with '0x'.
- -s, --size
The number of bytes to read from the NVRAM area. The parameter may either be a decimal number or a hexadecimal number starting with '0x'.
- -n, --offset (optional parameter)
The offset into the NVRAM area from where to start reading. The parameter may either be a decimal number or a hexadecimal number starting with '0x'.
- -f, --filename (optional parameter)
The name of a file the read data will be written into. If no filename is given the data will be printed to stdout.
tpm_nvdefine(8), tpm_nvinfo(8), tpm_nvrelease(8), tpm_nvwrite(8)
Report bugs to <firstname.lastname@example.org>
tpm_nvdefine(8), tpm_nvinfo(8), tpm_nvrelease(8), tpm_nvwrite(8).