Created Virtual Memory Manager interface

kernel/include/kernel/vmm.h

@@ -0,0 +1,71 @@
+#ifndef VMM_H_
+#define VMM_H_
+
+/*
+ * vmm_init:
+ *  Initialize the Virtual Memory Manager.
+ *
+ */
+
+void vmm_init(void);
+
+/*
+ * vmm_ptable_search:
+ *  Given a virtual address, search for its corresponding entry
+ *  in Page Table.
+ *
+ * @param ptable    - Pointer to the beginning of the Page Table
+ * @param virt_addr - Virtual address
+ *
+ * @return - Pointer to corresponding Page Table entry
+ *
+ */
+
+uint32_t *vmm_ptable_search(uint32_t *ptable, uint32_t virt_addr);
+
+/*
+ * vmm_pdir_search:
+ *  Given a virtual address, search for its corresponding entry
+ *  in Page Directory.
+ *
+ * @param pdir      - Pointer to the beginning of the Page Directory
+ * @param virt_addr - Virtual address
+ *
+ * @return - Pointer to corresponding Page Directory entry
+ *
+ */
+
+uint32_t *vmm_pdir_search(uint32_t *pdir, uint32_t virt_addr);
+
+/*
+ * vmm_install_pdir:
+ *  Install a Page Directory.
+ *
+ * @param pdir - Pointer to a Page Directory
+ *
+ */
+
+void vmm_install_pdir(uint32_t *pdir);
+
+/*
+ * vmm_flush_tlb:
+ *  Flush the Translation Lookaside Buffer.
+ *
+ * @param virt_tlb - Virtual address of TLB
+ *
+ */
+
+void vmm_flush_tlb(uint32_t virt_tlb);
+
+/*
+ * vmm_map_page:
+ *  Maps physical address to virtual address.
+ *
+ * @param phys - Physical address
+ * @param virt - Virtual address
+ *
+ */
+
+void vmm_map_addr(uint32_t phys, uint32_t virt);
+
+#endif

kernel/vmm/include/pe.h

@@ -0,0 +1,48 @@
+#ifndef PE_H_
+#define PE_H_
+
+#include <stdint.h>
+
+/*
+ * The following routines serve as a common interface for Page Directory and
+ * Page Table entries.
+ *
+ */
+
+/* Page Entry Flags. */
+
+enum PE_FLAGS {
+
+	PE_PRESENT		=	0x01,	  
+	PE_WRITABLE		=   0x02,	  
+	PE_USER			=   0x04,	  
+	PE_PWT			=   0x08,	  
+	PE_PCD			=   0x10, 
+	PE_ACCESSED		=	0x20, 
+	PE_DIRTY		=	0x40, 
+	PE_4MB			=	0x80, 
+	PE_CPU_GLOBAL	=	0x100,
+	PE_LV4_GLOBAL	=	0x200,
+   	PE_FRAME		=	0xFFFFF000
+
+};
+
+inline void pe_set_attr(uint32_t *e, uint32_t attr) { *e |= attr; }
+
+inline void pe_unset_attr(uint32_t *e, uint32_t attr) { *e &= ~attr; }
+
+void pe_set_frame(uint32_t *e, uint32_t addr) {
+    *e = (*e & ~PE_FRAME) | (addr << 12);
+}
+
+inline uint32_t pe_get_frame (uint32_t e) { return e & PE_FRAME; }
+
+inline int pe_is_present (uint32_t e) { return e & PE_PRESENT; }
+
+inline int pe_is_writable (uint32_t e) { return e & PE_WRITABLE; }
+
+inline int pe_is_user (uint32_t e) { return e & PE_USER; }
+
+inline int pe_is_4mb (uint32_t e) { return e & PE_4MB; }
+
+#endif