Merge branch 'develop-BA-FS26' into 'develop'HEADdevelop

Merge of BA-FS26 branch into develop

See merge request teachos/kernel!49

1 files changed, 71 insertions, 0 deletions

diff --git a/kernel/src/devices/storage/ram_disk/device.cpp b/kernel/src/devices/storage/ram_disk/device.cpp
new file mode 100644
index 0000000..1557204
--- /dev/null
+++ b/kernel/src/devices/storage/ram_disk/device.cpp
@@ -0,0 +1,71 @@
+#include <kernel/devices/storage/ram_disk/device.hpp>
+
+#include <kernel/devices/block_device.hpp>
+
+#include <kapi/boot_module/boot_module.hpp>
+#include <kapi/system.hpp>
+
+#include <kstd/cstring>
+#include <kstd/string>
+
+#include <cstddef>
+
+namespace kernel::devices::storage::ram_disk
+{
+  namespace
+  {
+    constexpr size_t ram_disk_block_size = 512uz;
+  }  // namespace
+
+  device::device(kapi::boot_modules::boot_module const & module, size_t major, size_t minor)
+      : block_device(major, minor, "ram" + kstd::to_string(minor), ram_disk_block_size)
+      , m_boot_module(module)
+  {}
+
+  auto device::init() -> bool
+  {
+    return m_boot_module.start_address.raw() != 0 && m_boot_module.size > 0;
+  }
+
+  auto device::read_block(size_t block_index, void * buffer) const -> void
+  {
+    if (buffer == nullptr)
+    {
+      kapi::system::panic("[RAM DISK DEVICE] read_block called with null buffer.");
+    }
+
+    auto const info = calculate_transfer(block_index);
+
+    if (info.to_transfer > 0)
+    {
+      auto const src = static_cast<std::byte const *>(m_boot_module.start_address) + info.offset;
+      kstd::libc::memcpy(buffer, src, info.to_transfer);
+    }
+
+    if (info.remainder > 0)
+    {
+      kstd::libc::memset(static_cast<std::byte *>(buffer) + info.to_transfer, 0, info.remainder);
+    }
+  }
+
+  auto device::write_block(size_t block_index, void const * buffer) -> void
+  {
+    if (buffer == nullptr)
+    {
+      kapi::system::panic("[RAM DISK DEVICE] write_block called with null buffer.");
+    }
+
+    auto const info = calculate_transfer(block_index);
+
+    if (info.to_transfer > 0)
+    {
+      auto const dest = static_cast<std::byte *>(m_boot_module.start_address) + info.offset;
+      kstd::libc::memcpy(dest, buffer, info.to_transfer);
+    }
+  }
+
+  auto device::size() const -> size_t
+  {
+    return m_boot_module.size;
+  }
+}  // namespace kernel::devices::storage::ram_disk
\ No newline at end of file