feat: Initial PMM implementation

Introduce the foundational Physical Memory Manager (PMM) and restructure the project for modularity.
Implemented basic PMM and related memory management headers (mm/pmm.h, mm/vm.h).
Updated Makefile and build process to support new modular structure.

2 files changed, 34 insertions, 0 deletions

diff --git a/include/kernel/mm.h b/include/kernel/mm.h
new file mode 100644
index 0000000..0f7c73d
--- /dev/null
+++ b/include/kernel/mm.h
@@ -0,0 +1,21 @@
+#pragma once
+#include "common/types.h"
+
+namespace VM
+{
+    typedef uint64_t* pagetable_t;
+    typedef uint64_t pte_t;
+    typedef uint64_t uint64;
+
+    #define PTE_V (1L << 0)
+    #define PTE_R (1L << 1)
+    #define PTE_W (1L << 2)
+    #define PTE_X (1L << 3)
+    #define PTE_U (1L << 4)
+
+    #define SATP_SV39 (8L << 60)
+    #define MAKE_SATP(pagetable) (SATP_SV39 | (((uint64)pagetable) >> 12))
+
+    void kvminit();
+    void kvminithart();
+}
\ No newline at end of file
diff --git a/include/kernel/pmm.h b/include/kernel/pmm.h
new file mode 100644
index 0000000..3328450
--- /dev/null
+++ b/include/kernel/pmm.h
@@ -0,0 +1,13 @@
+#pragma once
+#include "common/types.h"
+
+#define PHYSTOP (0x80000000 + 128 * 1024 * 1024)
+#define PGSIZE 4096
+
+namespace PMM{
+    void init();
+
+    void* alloc_page();
+
+    void free_page(void* pa);
+}
\ No newline at end of file