From ab93ad2de12a1376d98fcc6c533ccefc3f64654a Mon Sep 17 00:00:00 2001
From: lucic71 <lucic71@ctrl-c.club>
Date: Tue, 28 Jun 2022 19:40:51 +0300
Subject: [PATCH] Updated vmm and pmm

---
 kernel/include/kernel/pmm.h |  6 ++--
 kernel/include/kernel/vmm.h | 70 ++++++++++---------------------------
 kernel/pmm/src/pmm.c        |  4 +--
 3 files changed, 24 insertions(+), 56 deletions(-)

diff --git a/kernel/include/kernel/pmm.h b/kernel/include/kernel/pmm.h
index f33ff6b..a9ef40e 100644
--- a/kernel/include/kernel/pmm.h
+++ b/kernel/include/kernel/pmm.h
@@ -12,12 +12,12 @@
  * pmm_init:
  *  Initializes the Physical Memory Manager.
  *
- * @param mmap_addr - Physical memory address of memory map data structure
- * @param size      - Size of available physical memory in KB
+ * @param pmmap_addr - Physical memory address of memory map data structure
+ * @param size       - Size of available physical memory in KB
  *
  */
 
-void pmm_init(uint32_t mmap_addr, size_t size);
+void pmm_init(uint32_t pmmap_addr, size_t size);
 
 /*
  * pmm_init_region:
diff --git a/kernel/include/kernel/vmm.h b/kernel/include/kernel/vmm.h
index e34e8b8..13c2b1d 100644
--- a/kernel/include/kernel/vmm.h
+++ b/kernel/include/kernel/vmm.h
@@ -1,71 +1,39 @@
 #ifndef VMM_H_
 #define VMM_H_
 
+#include <stdint.h>
+
 /*
  * vmm_init:
- *  Initialize the Virtual Memory Manager.
+ *  Initialize the Virtual Memory Manager. At the moment it does not
+ *  support Higher Half Kernel. It just identity-maps the first 4MB
+ *  of physical memory.
  *
  */
 
 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.
+ *  Maps physical address to virtual address. This routine must be called
+ *  only after paging was enabled (aka after vmm_init).
  *
  * @param phys - Physical address
  * @param virt - Virtual address
  *
  */
 
-void vmm_map_addr(uint32_t phys, uint32_t virt);
+int vmm_map_addr(uint32_t phys, uint32_t virt);
+
+/*
+ * vmm_unmap_page:
+ *  Unmaps a virtual address. This routine must be called only after paging
+ *  was enabled (aka after vmm_init).
+ *
+ * @param virt - Virtual address
+ *
+ */
+
+void vmm_unmap_addr(uint32_t virt);
 
 #endif
diff --git a/kernel/pmm/src/pmm.c b/kernel/pmm/src/pmm.c
index 09e9d53..e322fa9 100644
--- a/kernel/pmm/src/pmm.c
+++ b/kernel/pmm/src/pmm.c
@@ -17,12 +17,12 @@
  *
  */
 
-void pmm_init(uint32_t mmap_addr, size_t size) {
+void pmm_init(uint32_t pmmap_addr, size_t size) {
 
     mem_size    = size;
     max_blocks  = (mem_size * 1024) / BLOCK_SIZE;
     used_blocks = max_blocks;
-    pmmap       = (uint32_t *) mmap_addr;
+    pmmap       = (uint32_t *) pmmap_addr;
 
     pmmap_size = mem_size / BLOCKS_PER_BYTE;
     if (mem_size % BLOCKS_PER_BYTE)