/** @file
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Large Variable Lib Common Header
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These libraries is used to store large data sets using the UEFI Variable
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Services. At time of writing, most UEFI Variable Services implementations do
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not allow more than 64KB of data to be stored in a single UEFI variable. This
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library will split data sets across multiple variables as needed.
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In the case where more than one variable is needed to store the data, an
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integer number will be added to the end of the variable name. This number
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will be incremented for each variable as needed to retrieve the entire data
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set.
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Copyright (c) 2021, Intel Corporation. All rights reserved.<BR>
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SPDX-License-Identifier: BSD-2-Clause-Patent
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**/
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#ifndef _LARGE_VARIABLE_COMMON_H_
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#define _LARGE_VARIABLE_COMMON_H_
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//
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// 1024 was choosen because this is the size of the SMM communication buffer
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// used by VariableDxeSmm to transfer the VariableName from DXE to SMM. Choosing
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// the same size will prevent this library from limiting variable names any
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// more than the MdeModulePkg implementation of UEFI Variable Services does.
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//
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#define MAX_VARIABLE_NAME_SIZE 1024
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//
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// The 2012 Windows Hardware Requirements specified a minimum variable size of
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// 32KB. By setting the maximum allowed number of variables to 0x20000, this
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// allows up to 4GB of data to be stored on most UEFI implementations in
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// existence. Older UEFI implementations were known to only provide 8KB per
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// variable. In this case, up to 1GB can be stored. Since 1GB vastly exceeds the
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// size of any known NvStorage FV, choosing this number should effectively
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// enable all available NvStorage space to be used to store the given data.
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//
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#define MAX_VARIABLE_SPLIT 131072 // 0x20000
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//
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// There are 6 digits in the number 131072, which means the length of the string
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// representation of this number will be at most 6 characters long.
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//
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#define MAX_VARIABLE_SPLIT_DIGITS 6
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//
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// On some architectures (Ex. Itanium) there a requirement to
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// maintain DWORD alignment of the variable data. Hence the
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// maximum possible padding size is 3.
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//
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#define MAX_VARIABLE_NAME_PAD_SIZE 3
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#endif // _LARGE_VARIABLE_COMMON_H_
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