Create a MemoryObject class and use it to load programs.

zion/object/memory_object.cpp

@@ -0,0 +1,63 @@
+#include "object/memory_object.h"
+
+#include "boot/boot_info.h"
+#include "debug/debug.h"
+#include "memory/physical_memory.h"
+
+MemoryObject::MemoryObject(uint64_t size) : size_(size) {
+  if ((size & 0xFFF) != 0) {
+    size_ = (size & ~0xFFF) + 0x1000;
+    dbgln("MemoryObject: aligned %x to %x", size, size_);
+  }
+  // FIXME: Do this lazily.
+  uint64_t num_pages = size_ / 0x1000;
+  for (uint64_t i = 0; i < num_pages; i++) {
+    phys_page_list_.PushBack(0);
+  }
+}
+
+uint64_t MemoryObject::PhysicalPageAtOffset(uint64_t offset) {
+  if (offset > size_) {
+    panic("Invalid offset");
+  }
+  uint64_t page_num = offset / 0x1000;
+  return PageNumberToPhysAddr(page_num);
+}
+
+void MemoryObject::CopyBytesToObject(uint64_t source, uint64_t length) {
+  if (length > size_) {
+    panic("Copy overruns memory object: %x too large for %x", length, size_);
+  }
+  uint64_t hhdm = boot::GetHigherHalfDirectMap();
+  uint64_t page_number = 0;
+  while (length > 0) {
+    uint64_t physical = hhdm + PageNumberToPhysAddr(page_number);
+
+    uint64_t bytes_to_copy = length >= 0x1000 ? 0x1000 : length;
+
+    uint8_t* srcptr = reinterpret_cast<uint8_t*>(source);
+    uint8_t* destptr = reinterpret_cast<uint8_t*>(physical);
+    for (uint64_t i = 0; i < bytes_to_copy; i++) {
+      destptr[i] = srcptr[i];
+    }
+
+    length -= bytes_to_copy;
+    source += 0x1000;
+    page_number++;
+  }
+}
+
+uint64_t MemoryObject::PageNumberToPhysAddr(uint64_t page_num) {
+  auto iter = phys_page_list_.begin();
+  uint64_t index = 0;
+  while (index < page_num) {
+    ++iter;
+    index++;
+  }
+
+  if (*iter == 0) {
+    dbgln("Allocating page num %u for mem object", page_num);
+    *iter = phys_mem::AllocatePage();
+  }
+  return *iter;
+}