From 4f214b2d5aef74ec5fa7595929ff1e96842787b4 Mon Sep 17 00:00:00 2001
From: Maxime Bloch <me@mcbloch.dev>
Date: Tue, 28 Jan 2020 18:54:42 +0100
Subject: [PATCH]  Add printing on terminal. Add some usage on boot.

---
 kernel/kernel.c      |  30 +++++++-
 kernel/linked_list.c | 148 --------------------------------------
 kernel/memory.c      | 168 ++++++++++++++++++++++++++++++++++++++++---
 3 files changed, 187 insertions(+), 159 deletions(-)
 delete mode 100644 kernel/linked_list.c

diff --git a/kernel/kernel.c b/kernel/kernel.c
index 7fa4427..21003f9 100644
--- a/kernel/kernel.c
+++ b/kernel/kernel.c
@@ -54,10 +54,34 @@ void kernel_main(void)
 	}
 	management_str[13] = 0;
 
-	terminal_writestring(memory_str);
-	terminal_writestring(management_str);
 
-	terminal_writestring((are_interrupts_enabled())? "Interrupts!\n": "No interrupts :(\n");
+    terminal_writestring(memory_str);
+    terminal_writestring(management_str);
+
+    terminal_writestring("Mem after freeing!\n");
+    free(memory_str);
+    print_memory();
+	free(management_str);
+    print_memory();
+
+    char* memory_after_free = alloc(sizeof(char) * 12);
+    for (int i = 0; i < 13; i++) {
+        memory_after_free[i] = " Some text\n"[i];
+    }
+    memory_after_free[13] = 0;
+
+    terminal_writestring(memory_after_free);
+
+    terminal_writestring("Memory after new allocation!\n");
+    alloc(1000);
+    print_memory();
+
+    terminal_writestring("Free again\n");
+    free(memory_after_free);
+    print_memory();
+
+
+    terminal_writestring((are_interrupts_enabled())? "Interrupts!\n": "No interrupts :(\n");
 
 	interrupt_init();
 
diff --git a/kernel/linked_list.c b/kernel/linked_list.c
deleted file mode 100644
index 0607e88..0000000
--- a/kernel/linked_list.c
+++ /dev/null
@@ -1,148 +0,0 @@
-#ifndef LINKED_LIST_C
-#define LINKED_LIST_C
-
-#include <stdbool.h>
-#include <stdio.h>
-#include <stdlib.h>
-
-typedef struct page_tag {
-    size_t size;
-
-    struct page_tag *prev;
-    struct page_tag *next;
-} page_tag;
-
-
-page_tag *start;
-
-
-page_tag *__searchPage(void *data) {
-    page_tag *curr_page = start;
-    while (curr_page + (sizeof(page_tag)) != data) {
-        curr_page = curr_page->next;
-    }
-    return curr_page;
-}
-
-///**
-// * @param alignment
-// * @param size
-// * @return A block aligned with the alignment parameter.
-// */
-//void* aligned_alloc(int alignment, int size){
-//    // TODO
-//    return NULL;
-//}
-
-void *__alloc(size_t size) {
-    page_tag *curr_page = start;
-
-    while (curr_page->next != NULL) {
-        page_tag *new_page = ((void *) curr_page) + sizeof(page_tag) + curr_page->size;
-        if ((void *) new_page + sizeof(page_tag) + size <= curr_page->next) {
-
-            new_page->size = size;
-
-            curr_page->next->prev = new_page;
-            new_page->next = curr_page->next;
-
-            curr_page->next = new_page;
-            new_page->prev = curr_page;
-
-            return new_page + 1;
-        }
-        curr_page = curr_page->next;
-    }
-
-    page_tag *new_page = ((void *) curr_page) + sizeof(page_tag) + curr_page->size;
-    new_page->size = size;
-
-    curr_page->next = new_page;
-    new_page->prev = curr_page;
-    return new_page + 1;
-}
-
-void __free(void *data) {
-    page_tag *data_tag = data - sizeof(page_tag);
-    printf("found tag at %p\n", data_tag);
-
-    data_tag->prev->next = data_tag->next;
-    data_tag->next->prev = data_tag->prev;
-}
-
-void print() {
-    printf("==== MEM DUMP ====\n");
-    page_tag *curr_page = start;
-    int i = 0;
-    while (curr_page != NULL) {
-        printf("%d: [%p (%zu)] [%p (%zu)]\n",
-               i,
-               curr_page, sizeof(page_tag),
-               curr_page + 1, curr_page->size);
-
-        void *empty_start = (void *) curr_page + sizeof(page_tag) + curr_page->size;
-        if (empty_start + sizeof(page_tag) < (void *) curr_page->next) {
-            printf("empty_page (%ld, %ld)\n",
-                   sizeof(page_tag),
-                   (void *) curr_page->next -
-                   (empty_start + sizeof(page_tag)));
-
-        } else if (empty_start < (void *) curr_page->next) {
-            printf("not enough room (%ld)\n",
-                   (void *) curr_page->next - empty_start);
-        }
-        curr_page = curr_page->next;
-        i++;
-    }
-    printf("-------------------\n\n");
-}
-
-void test_allocs() {
-    void *ptr0 = __alloc(64);
-    void *ptr1 = __alloc(64);
-    void *ptr4 = __alloc(64);
-    print();
-
-    printf("Free nr 2 -> %p\n", ptr1);
-    __free(ptr1);
-    print();
-
-    printf("Alloc 32 bytes\n");
-    void *ptr2 = __alloc(32);
-    print();
-
-    printf("Alloc 32 bytes\n");
-    __alloc(32);
-    print();
-
-    printf("Alloc 8 bytes\n");
-    void *ptr3 = __alloc(8);
-    print();
-
-    __free(ptr2);
-    print();
-    __free(ptr4);
-    print();
-    __free(ptr3);
-    print();
-
-    __free(ptr0);
-    print();
-
-    printf("#########\nTry almost fill\n");
-    __alloc(160);
-    print();
-    __alloc(50);
-    print();
-
-
-}
-
-int main() {
-    start = malloc(sizeof(size_t) * 1000);
-    start->next = NULL;
-    start->prev = NULL;
-    test_allocs();
-}
-
-#endif // LINKED_LIST_C
diff --git a/kernel/memory.c b/kernel/memory.c
index a228222..80b1ef3 100644
--- a/kernel/memory.c
+++ b/kernel/memory.c
@@ -1,13 +1,165 @@
-#ifndef MEMORY_C
-#define MEMORY_C
+#ifndef LINKED_LIST_C
+#define LINKED_LIST_C
+
 
 #include <stddef.h>
 
-void* _curr_end = (void*) 0x200000;
+#include "terminal.c"
 
-void* alloc(size_t size) {
-    void* thanks_jp = _curr_end;
-    _curr_end += size;
-    return thanks_jp;
+#define MEMORY_START 0x200000
+//#define MEMORY_END 0x300000
+
+//size_t total_memory = MEMORY_END - MEMORY_START;
+
+typedef struct page_tag {
+    size_t size;
+
+    struct page_tag *prev;
+    struct page_tag *next;
+} page_tag;
+
+
+page_tag *start = (void *) MEMORY_START;;
+
+
+page_tag *__searchPage(void *data) {
+    page_tag *curr_page = start;
+    while (curr_page + (sizeof(page_tag)) != data) {
+        curr_page = curr_page->next;
+    }
+    return curr_page;
 }
-#endif // MEMORY_C
\ No newline at end of file
+
+void *alloc(size_t size) {
+    page_tag *curr_page = start;
+
+    while (curr_page->next != NULL) {
+        page_tag *new_page = ((void *) curr_page) + sizeof(page_tag) + curr_page->size;
+        if ((void *) new_page + sizeof(page_tag) + size <= (void *) curr_page->next) {
+
+            new_page->size = size;
+
+            curr_page->next->prev = new_page;
+            new_page->next = curr_page->next;
+
+            curr_page->next = new_page;
+            new_page->prev = curr_page;
+
+            return new_page + 1;
+        }
+        curr_page = curr_page->next;
+    }
+
+    page_tag *new_page = ((void *) curr_page) + sizeof(page_tag) + curr_page->size;
+    new_page->size = size;
+
+    curr_page->next = new_page;
+    new_page->prev = curr_page;
+    new_page->next = NULL;
+    return new_page + 1;
+}
+
+void free(void *data) {
+    page_tag *data_tag = data - sizeof(page_tag);
+
+    data_tag->prev->next = data_tag->next;
+    data_tag->next->prev = data_tag->prev;
+}
+
+void print_memory() {
+    terminal_write("==== MEM DUMP ====\n", 19);
+    page_tag *curr_page = start;
+    int i = 0;
+    while (curr_page != NULL) {
+        terminal_writeint(i, 10);
+        terminal_write(": [", 3);
+        terminal_writeint((int) curr_page, 16);
+        terminal_write(" ", 1);
+        terminal_writeint(sizeof(page_tag), 10);
+        terminal_write("] [", 3);
+        terminal_writeint((int) (curr_page + 1), 16);
+        terminal_write(" ", 1);
+        terminal_writeint(curr_page->size, 10);
+        terminal_writestring("]\n");
+
+//        printf("%d: [%p (%zu)] [%p (%zu)]\n",
+//               i,
+//               curr_page, sizeof(page_tag),
+//               curr_page + 1, curr_page->size);
+
+
+        void *empty_start = (void *) curr_page + sizeof(page_tag) + curr_page->size;
+        if (empty_start + sizeof(page_tag) < (void *) curr_page->next) {
+            terminal_writestring("empty_page (");
+            terminal_writeint(sizeof(page_tag), 10);
+            terminal_writestring(", ");
+            terminal_writeint(
+                    (void *) curr_page->next -
+                    (empty_start + sizeof(page_tag)), 10);
+            terminal_writestring(")\n");
+//            printf("empty_page (%ld, %ld)\n",
+//                   sizeof(page_tag),
+//                   (void *) curr_page->next -
+//                   (empty_start + sizeof(page_tag)));
+        } else if (empty_start < (void *) curr_page->next) {
+            terminal_writestring("not enough room (");
+            terminal_writeint((void *) curr_page->next - empty_start, 10);
+            terminal_writestring(")\n");
+//            printf("not enough room (%ld)\n",
+//                   (void *) curr_page->next - empty_start);
+        }
+        curr_page = curr_page->next;
+        i++;
+    }
+    terminal_write("------------------\n\n", 20);
+}
+//
+//void test_allocs() {
+//    void *ptr0 = __alloc(64);
+//    void *ptr1 = __alloc(64);
+//    void *ptr4 = __alloc(64);
+//    print();
+//
+//    printf("Free nr 2 -> %p\n", ptr1);
+//    __free(ptr1);
+//    print();
+//
+//    printf("Alloc 32 bytes\n");
+//    void *ptr2 = __alloc(32);
+//    print();
+//
+//    printf("Alloc 32 bytes\n");
+//    __alloc(32);
+//    print();
+//
+//    printf("Alloc 8 bytes\n");
+//    void *ptr3 = __alloc(8);
+//    print();
+//
+//    __free(ptr2);
+//    print();
+//    __free(ptr4);
+//    print();
+//    __free(ptr3);
+//    print();
+//
+//    __free(ptr0);
+//    print();
+//
+//    printf("#########\nTry almost fill\n");
+//    __alloc(160);
+//    print();
+//    __alloc(50);
+//    print();
+//
+//
+//}
+//
+//int main() {
+//    start = malloc(sizeof(size_t) * 1000);
+//    start->next = NULL;
+//    start->prev = NULL;
+//    test_allocs();
+//}
+
+#endif // LINKED_LIST_C