tools: io: add read method
Add method for reading the host's memory to enable reading the PCI
configuration.
Tested: Verified it's able to read a memory BAR associated with the
ASPEED ast2400.
Change-Id: Id06f30b063e69825f2dfa69786b69392657f7b1c
Signed-off-by: Patrick Venture <venture@google.com>
diff --git a/tools/io.cpp b/tools/io.cpp
index e25216e..75677f4 100644
--- a/tools/io.cpp
+++ b/tools/io.cpp
@@ -13,6 +13,37 @@
const std::string DevMemDevice::devMemPath = "/dev/mem";
+bool DevMemDevice::read(const std::size_t offset, const std::size_t length,
+ void* const destination)
+{
+ if (!opened)
+ {
+ devMemFd = sys->open(devMemPath.c_str(), O_RDWR);
+ if (devMemFd < 0)
+ {
+ return false;
+ }
+
+ opened = true;
+ }
+
+ // addr, length, prot, flags, fd, offset
+ devMemMapped =
+ sys->mmap(0, length, PROT_WRITE, MAP_SHARED, devMemFd, offset);
+ if (devMemMapped == MAP_FAILED)
+ {
+ return false; /* but leave the file open. */
+ }
+
+ /* Copy the bytes. */
+ std::memcpy(destination, devMemMapped, length);
+
+ /* Close the map between reads for now. */
+ sys->munmap(devMemMapped, length);
+
+ return true;
+}
+
bool DevMemDevice::write(const std::size_t offset, const std::size_t length,
const void* const source)
{