blob: 420dd941cda7f1b9be91fdad284d43d03f89c2bf [file] [log] [blame]
#include "io.hpp"
#include "internal/sys.hpp"
#include <fcntl.h>
#include <cstdint>
#include <cstring>
#include <string>
namespace host_tool
{
const std::string DevMemDevice::devMemPath = "/dev/mem";
bool DevMemDevice::read(const std::size_t offset, const std::size_t length,
void* const destination)
{
devMemFd = sys->open(devMemPath.c_str(), O_RDONLY);
if (devMemFd < 0)
{
return false;
}
/* Map based on aligned addresses - behind the scenes. */
const std::size_t alignedDiff = offset % sys->getpagesize();
const std::size_t alignedOffset = offset - alignedDiff;
const std::size_t alignedSize = length + alignedDiff;
// addr, length, prot, flags, fd, offset
devMemMapped = sys->mmap(0, alignedSize, PROT_READ, MAP_SHARED, devMemFd,
alignedOffset);
if (devMemMapped == MAP_FAILED)
{
std::fprintf(stderr, "Failed to mmap at offset: 0x%lx, length: %lu\n",
offset, length);
sys->close(devMemFd);
return false;
}
void* alignedSource =
static_cast<std::uint8_t*>(devMemMapped) + alignedDiff;
/* Copy the bytes. */
std::memcpy(destination, alignedSource, length);
/* Close the map between reads for now. */
sys->munmap(devMemMapped, length);
sys->close(devMemFd);
return true;
}
bool DevMemDevice::write(const std::size_t offset, const std::size_t length,
const void* const source)
{
devMemFd = sys->open(devMemPath.c_str(), O_RDWR);
if (devMemFd < 0)
{
std::fprintf(stderr, "Failed to open /dev/mem for writing\n");
return false;
}
/* Map based on aligned addresses - behind the scenes. */
const std::size_t alignedDiff = offset % sys->getpagesize();
const std::size_t alignedOffset = offset - alignedDiff;
const std::size_t alignedSize = length + alignedDiff;
// addr, length, prot, flags, fd, offset
devMemMapped = sys->mmap(0, alignedSize, PROT_WRITE, MAP_SHARED, devMemFd,
alignedOffset);
if (devMemMapped == MAP_FAILED)
{
std::fprintf(stderr, "Failed to mmap at offset: 0x%lx, length: %lu\n",
offset, length);
sys->close(devMemFd);
return false;
}
void* alignedDestination =
static_cast<std::uint8_t*>(devMemMapped) + alignedDiff;
/* Copy the bytes. */
std::memcpy(alignedDestination, source, length);
/* Close the map between writes for now. */
sys->munmap(devMemMapped, length);
sys->close(devMemFd);
return true;
}
} // namespace host_tool