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#pragma once
#include <vector>
#include <memory>
#include <numeric>
#include <experimental/filesystem>
#include "pnor_partition_defs.h"
namespace openpower
{
namespace virtual_pnor
{
namespace fs = std::experimental::filesystem;
using PartitionTable = std::vector<uint8_t>;
using checksum_t = uint32_t;
/** @brief Convert the input partition table to big endian.
*
* @param[in] src - reference to the pnor partition table
*
* @returns converted partition table
*/
PartitionTable endianFixup(const PartitionTable& src);
namespace details
{
/** @brief Compute XOR-based checksum, by XORing consecutive words
* in the input data. Input must be aligned to word boundary.
*
* @param[in] data - input data on which checksum is computed
*
* @returns computed checksum
*/
template <class T> checksum_t checksum(const T& data)
{
static_assert(sizeof(decltype(data)) % sizeof(checksum_t) == 0,
"sizeof(data) is not aligned to sizeof(checksum_t) boundary");
auto begin = reinterpret_cast<const checksum_t*>(&data);
auto end = begin + (sizeof(decltype(data)) / sizeof(checksum_t));
return std::accumulate(begin, end, 0, std::bit_xor<checksum_t>());
}
} // namespace details
namespace partition
{
/** @class Table
* @brief Generates virtual PNOR partition table.
*
* Generates virtual PNOR partition table upon construction. Reads
* the PNOR information generated by this tool :
* github.com/openbmc/openpower-pnor-code-mgmt/blob/master/generate-squashfs,
* which generates a minimalistic table-of-contents (toc) file and
* individual files to represent various partitions that are of interest -
* these help form the "virtual" PNOR, which is typically a subset of the full
* PNOR image.
* These files are stored in a well-known location on the PNOR.
* Based on this information, this class prepares the partition table whose
* structure is as outlined in pnor_partition.h.
*
* The virtual PNOR supports 4KB erase blocks - partitions must be aligned to
* this size.
*/
class Table
{
public:
/** @brief Constructor accepting the path of the directory
* that houses the PNOR partition files.
*
* @param[in] directory - path of the directory housing PNOR partitions
* @param[in] blockSize - PNOR block size, in bytes. See
* open-power/hostboot/blob/master/src/usr/pnor/ffs.h for
* the PNOR FFS structure.
* @param[in] pnorSize - PNOR size, in bytes
*/
Table(fs::path&& directory, size_t blockSize, size_t pnorSize);
/** @brief Constructor - creates partition table
*
* @param[in] blockSize - PNOR block size, in bytes
* @param[in] pnorSize - PNOR size, in bytes
*/
Table(size_t blockSize, size_t pnorSize);
Table(const Table&) = delete;
Table& operator=(const Table&) = delete;
Table(Table&&) = delete;
Table& operator=(Table&&) = delete;
~Table() = default;
/** @brief Return size of partition table
*
* @returns size_t - size of partition table in blocks
*/
size_t size() const
{
return szBlocks;
}
/** @brief Return a partition table having byte-ordering
* that the host expects.
*
* The host needs the partion table in big-endian.
*
* @returns const reference to host partition table.
*/
const pnor_partition_table& getHostTable() const
{
return *(reinterpret_cast<const pnor_partition_table*>(hostTbl.data()));
}
/** @brief Return a little-endian partition table
*
* @returns const reference to native partition table
*/
const pnor_partition_table& getNativeTable() const
{
return *(reinterpret_cast<const pnor_partition_table*>(tbl.data()));
}
/** @brief Return partition corresponding to PNOR offset, the offset
* is within returned partition.
*
* @param[in] offset - PNOR offset in bytes
*
* @returns const reference to pnor_partition, if found, else an
* exception will be thrown.
*/
const pnor_partition& partition(size_t offset) const;
/** @brief Return partition corresponding to input partition name.
*
* @param[in] name - PNOR partition name
*
* @returns const reference to pnor_partition, if found, else an
* exception will be thrown.
*/
const pnor_partition& partition(const std::string& name) const;
private:
/** @brief Prepares a vector of PNOR partition structures.
*/
void preparePartitions();
/** @brief Prepares the PNOR header.
*/
void prepareHeader();
/** @brief Allocate memory to hold the partion table. Determine the
* amount needed based on the partition files in the toc file.
*
* @param[in] tocFile - Table of contents file path.
*/
void allocateMemory(const fs::path& tocFile);
/** @brief Populate fields related to sizes for the input
* pnor_partition structure.
*
* @param[in/out] part - pnor_partition structure
* @param[in] start - partition start address
* @param[in] end - partition end address
*/
void writeSizes(pnor_partition& part, size_t start, size_t end);
/** @brief Populate userdata bits for the input
* pnor_partition structure.
*
* @param[in/out] part - pnor_partition structure
* @param[in] version - partition version check algorithm to be used
* (see pnor_partition_defs.h)
* @param[in] data - string having userdata fields in a
* comma-separated line.
*/
void writeUserdata(pnor_partition& part, uint32_t version,
const std::string& data);
/** @brief Populate the name and id fields for the input
* pnor_partition structure.
*
* @param[in/out] part - pnor_partition structure
* @param[in] name - partition name
* @param[id] id - partition id
*/
void writeNameAndId(pnor_partition& part, std::string&& name,
const std::string& id);
/** @brief Populate default/unused fields for the input
* pnor_partition structure.
*
* @param[in/out] part - pnor_partition structure
*/
void writeDefaults(pnor_partition& part);
/** @brief Return a little-endian partition table
*
* @returns reference to native partition table
*/
pnor_partition_table& getNativeTable()
{
return *(reinterpret_cast<pnor_partition_table*>(tbl.data()));
}
/** @brief Size of the PNOR partition table -
* sizeof(pnor_partition_table) +
* (no. of partitions * sizeof(pnor_partition)),
* measured in erase-blocks.
*/
size_t szBlocks;
/** @brief Partition table */
PartitionTable tbl;
/** @brief Partition table with host byte ordering */
PartitionTable hostTbl;
/** @brief Directory housing generated PNOR partition files */
fs::path directory;
/** @brief Number of partitions */
size_t numParts;
/** @brief PNOR block size, in bytes */
size_t blockSize;
/** @brief PNOR size, in bytes */
size_t pnorSize;
};
} // namespace partition
} // namespace virtual_pnor
} // namespace openpower
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