From cfdb33fc7750707911a6d4ef6a698af05d4f2698 Mon Sep 17 00:00:00 2001
From: notsomeidiot123 <kiminosei321@gmail.com>
Date: Wed, 30 Oct 2024 13:39:33 -0400
Subject: [PATCH] Added or completed: map(), unmap() pm_reserve(), pm_alloc(),
 pm_free(), pm_init(), get_paddr()

---
 .gitignore                    |  3 +-
 src/kernel/arch_i386/memory.c | 85 +++++++++++++++++++++++++++++++++--
 src/kernel/drivers/serial.c   |  9 ++++
 src/kernel/shared/kstdlib.h   |  6 ++-
 src/kernel/shared/memory.h    |  1 +
 5 files changed, 97 insertions(+), 7 deletions(-)

diff --git a/.gitignore b/.gitignore
index 6a4e642..c210e0b 100644
--- a/.gitignore
+++ b/.gitignore
@@ -7,4 +7,5 @@ diskwrite
 *.elf
 *.dump
 intlog.*
-*.img
\ No newline at end of file
+*.img
+.gitignore
\ No newline at end of file
diff --git a/src/kernel/arch_i386/memory.c b/src/kernel/arch_i386/memory.c
index 4a89f8b..9f79f13 100644
--- a/src/kernel/arch_i386/memory.c
+++ b/src/kernel/arch_i386/memory.c
@@ -1,12 +1,58 @@
 #include <stdint.h>
 #include "../shared/memory.h"
 #include "../shared/kstdlib.h"
-uint8_t pm_map[0x20000];
 
-int pm_alloc(){
-    
+#define mmap_count 0x200000
+
+uint8_t pm_map[mmap_count];
+
+uint32_t total_memory;
+uint32_t total_memory_usable;
+uint32_t last_allocated;
+
+
+uint32_t pm_alloc(){
+    for(uint32_t i = 0; i < mmap_count; i++){
+        for(int j = 0; j < 8; j++){
+            if(!(pm_map[i] & (1 << j))){
+                return (i << 3 | j) << 12;
+            }
+        }
+    }
 }
+void pm_free(uint32_t address){
+    pm_map[address >> 15] &= ~(1 << ((address>>12) & 7));
+}
+void pm_reserve(uint32_t address){
+    pm_map[address >> 15] |= 1 << ((address>>12) & 7);
+}
+
 int pm_init(kernel_info_t *kernel_info){
+    mmap_entry_t *mmap = (mmap_entry_t*)(kernel_info->mmap_ptr);
+    // printf("mmap count: %d", kernel_info->mmap_entry_count);
+    for(uint32_t i = 0; i < mmap_count; i++){
+        pm_map[i] = 0;
+    }
+    for(uint32_t i = 0; i < kernel_info->mmap_entry_count; i++){
+        for(uint32_t j = 0; j < (mmap[i].entry_length >> 12); j++){
+            // printf("j = %d\nIndex:%x\n", j, (mmap[i].entry_base >> 12) + (j & 3));
+            if(mmap[i].type != BIOS_MMAP_USABLE){
+                pm_map[(mmap[i].entry_base >> 12) + (j >> 3)] |= 1 << (j & 7);
+            }
+            else{
+                // uint8_t tmp = pm_map[(mmap[i].entry_base >> 12 ) + (j >> 3)];
+                // tmp &= ~(1 << (j & 3));
+                pm_map[(mmap[i].entry_base >> 12) + (j >> 3)] &= ~(1 << (j & 7));
+            }
+            // if(j % 8 == 7){
+            //     printf("%d, %x, %d\n", j >> 3, pm_map[(mmap[i].entry_base >> 12 ) + (j >> 3)], mmap[i].type);
+            // }
+        }
+        
+    }
+    for(uint32_t i = 0; i < 512; i++){
+        pm_reserve(i * 4096);
+    }
     
 }
 void map(void *vaddr, void *paddr, uint32_t flags){
@@ -15,6 +61,37 @@ void map(void *vaddr, void *paddr, uint32_t flags){
     
     uint32_t *pd = (uint32_t*)0xfffff000;
     if(!pd[pd_index]){
-        pd[pd_index] = pm_alloc();
+        pd[pd_index] = pm_alloc() | 1;
     }
+    uint32_t *pt = (uint32_t *)(0xffc00000 + (pd_index * 0x400));
+    pt[pt_index] = (uint32_t)paddr | flags;
+    asm volatile("invlpg (%0)  " : : "b"(vaddr) : "memory");
 }
+void unmap(void *vaddr){
+    uint32_t pd_index = (uint32_t)vaddr >> 22;
+    uint32_t pt_index = (uint32_t)vaddr >> 12 & 0x3ff;
+    
+    uint32_t *pd = (uint32_t *)0xfffff000;
+    if(!pd[pd_index]){
+        return;
+    }
+    uint32_t *pt = (uint32_t *)(0xffc00000 + (pd_index * 0x400));
+    uint32_t paddr = pt[pt_index];
+    paddr ^= (paddr & 0xfff);
+    pm_free(paddr);
+    asm volatile("invlpg (%0)  " : : "b"(vaddr) : "memory");
+}
+void map_4mb(void *vaddr, void *paddr, uint32_t flags){
+    //just wanted to get the prototype out
+}
+uint32_t get_paddr(void *addr){
+    uint32_t vaddr = (uint32_t)addr;
+    uint32_t pd_index = vaddr >> 22;
+    uint32_t pt_index = vaddr >> 12 & 0x3ff;
+    uint32_t *pd = (uint32_t *)0xfffff000;
+    if(!pd[pd_index]){
+        return 0;
+    }
+    uint32_t *pt = (uint32_t *)(0xffc00000 + (0x400 * pd_index));
+    return pt[pt_index];
+}
\ No newline at end of file
diff --git a/src/kernel/drivers/serial.c b/src/kernel/drivers/serial.c
index c67ff1b..c2d12d5 100644
--- a/src/kernel/drivers/serial.c
+++ b/src/kernel/drivers/serial.c
@@ -57,6 +57,15 @@ void printf(char *string, ...){
                     itoa(num, numb, 10);
                     debug_puts(numb);
                     continue;
+                case 'x':
+                    // debug_puts(":3");
+                    string += 2;
+                    int32_t hex = va_arg(vars, int32_t);
+                    char hnumb[12];
+                    itoa(hex, hnumb, 16);
+                    strpad(hnumb, '0', 8);
+                    debug_puts(hnumb);
+                    continue;
             }
         }
         outb(com_ports[0], *string);
diff --git a/src/kernel/shared/kstdlib.h b/src/kernel/shared/kstdlib.h
index b2bb6a1..add36d6 100644
--- a/src/kernel/shared/kstdlib.h
+++ b/src/kernel/shared/kstdlib.h
@@ -1,6 +1,8 @@
-#include "memory.h"
+#pragma once
+// #include "memory.h"
+#include "../drivers/serial.h"
 typedef struct kernel_info{
-    memory_map_entry *mmap_ptr;
+    void *mmap_ptr;
     uint16_t mmap_entry_count;
     uint8_t padding;
     uint8_t pixel_depth;
diff --git a/src/kernel/shared/memory.h b/src/kernel/shared/memory.h
index e1cef09..0c768cb 100644
--- a/src/kernel/shared/memory.h
+++ b/src/kernel/shared/memory.h
@@ -1,5 +1,6 @@
 #pragma once
 #include <stdint.h>
+#include "kstdlib.h"
 
 #define PD_PRESENT  0x0001
 #define PD_USER_RW  0x0002