Add a memory region type to mammoth

lib/mammoth/CMakeLists.txt

@@ -1,6 +1,7 @@
 add_library(mammoth_lib STATIC
   src/channel.cpp
   src/debug.cpp
+  src/memory_region.cpp
   src/process.cpp
   src/thread.cpp
   )

lib/mammoth/include/mammoth/memory_region.h

@@ -0,0 +1,29 @@
+#pragma once
+
+#include <stdint.h>
+
+class MappedMemoryRegion {
+ public:
+  // FIXME: Introduce optional type to contain error or.
+  static MappedMemoryRegion DirectPhysical(uint64_t phys_addr, uint64_t size);
+  static MappedMemoryRegion ContiguousPhysical(uint64_t size);
+  static MappedMemoryRegion Default(uint64_t size);
+
+  MappedMemoryRegion() {}
+  // TODO: Disallow copy before doing any cleanup here.
+  ~MappedMemoryRegion() {}
+
+  uint64_t paddr() { return paddr_; }
+  uint64_t vaddr() { return vaddr_; }
+
+  operator bool() { return vmmo_cap_ != 0; }
+
+ private:
+  MappedMemoryRegion(uint64_t vmmo_cap, uint64_t paddr, uint64_t vaddr,
+                     uint64_t size)
+      : vmmo_cap_(vmmo_cap), paddr_(paddr), vaddr_(vaddr), size_(size) {}
+  uint64_t vmmo_cap_ = 0;
+  uint64_t paddr_ = 0;
+  uint64_t vaddr_ = 0;
+  uint64_t size_ = 0;
+};

lib/mammoth/src/memory_region.cpp

@@ -0,0 +1,36 @@
+#include "mammoth/memory_region.h"
+
+#include <zcall.h>
+
+#include "mammoth/debug.h"
+
+MappedMemoryRegion MappedMemoryRegion::DirectPhysical(uint64_t paddr,
+                                                      uint64_t size) {
+  uint64_t vmmo_cap;
+  check(ZMemoryObjectCreatePhysical(paddr, size, &vmmo_cap));
+
+  uint64_t vaddr;
+  check(ZAddressSpaceMap(Z_INIT_VMAS_SELF, 0, vmmo_cap, &vaddr));
+
+  return MappedMemoryRegion(vmmo_cap, paddr, vaddr, size);
+}
+
+MappedMemoryRegion MappedMemoryRegion::ContiguousPhysical(uint64_t size) {
+  uint64_t vmmo_cap, paddr;
+  check(ZMemoryObjectCreateContiguous(size, &vmmo_cap, &paddr));
+
+  uint64_t vaddr;
+  check(ZAddressSpaceMap(Z_INIT_VMAS_SELF, 0, vmmo_cap, &vaddr));
+
+  return MappedMemoryRegion(vmmo_cap, paddr, vaddr, size);
+}
+
+MappedMemoryRegion MappedMemoryRegion::Default(uint64_t size) {
+  uint64_t vmmo_cap;
+  check(ZMemoryObjectCreate(size, &vmmo_cap));
+
+  uint64_t vaddr;
+  check(ZAddressSpaceMap(Z_INIT_VMAS_SELF, 0, vmmo_cap, &vaddr));
+
+  return MappedMemoryRegion(vmmo_cap, 0, vaddr, size);
+}