Handout

kernel/memory/config.h

@@ -0,0 +1,20 @@
+#pragma once
+#include "../types.h"
+
+// External symbols introduced by the linker with kernel start and end address
+extern "C" void* ___KERNEL_START___;
+extern "C" void* ___KERNEL_END___;
+
+/*! \brief Lowest memory address we will make use of
+ * It seems wise to ignore everything below the first 1 MB
+ * since it is used by BIOS and memory mapped devices,
+ * and not every BIOS gives us a correct memory map.
+ */
+const uintptr_t KERNEL_SPACE = 0x100000;
+
+/*! \brief Border between Kernel and User space
+ * Memory below this border (starting by MINIMUM) is for kernel (which is
+ * identity mapped), memory above for user space.
+ * Let's choose 64 MB since this should be enough for the kernel.
+ */
+const uintptr_t USER_SPACE = 0x4000000;