Started using virtual memory manager in kernel. Also changes read() function to accept a char* to write to

include/c/stdio.h

@@ -5,10 +5,8 @@ void print(const char* s) { // Use Syscall(1) - Puts()
     __asm__ volatile ("int $0x80" : : "a"(1), "b"(s));
 }
 
-char* read() { // Use Syscall(2) - Gets()
-    char* s;
-    __asm__ volatile ("int $0x80" : "=b"(s) : "a"(2));
-    return s;
+void read(char* s) { // Use Syscall(2) - Gets()
+    __asm__ volatile ("int $0x80" : : "a"(2), "b"(s));
 }
 
 #endif

include/interrupt/syscall.h

@@ -24,22 +24,22 @@ void sys_sleep() {
 void sys_puts() {
     char* s;
     __asm__ volatile ("movl %%ebx, %0" : "=r"(s));
-
     print(s);
 }
 
 // TODO: Use a Read() sycall and read from stdin
-// Returns: ebx - char* string
+// Args: ebx - char* buffer
 void sys_gets() {
-    char* s = read();
-    __asm__ volatile ("movl %0, %%ebx" :: "r"(s));
+    char* s;
+    __asm__ volatile ("movl %%ebx, %0" : "=r"(s));
+    read(s);
 }
 
 // System call table
 void* syscalls[MAX_SYSCALLS] = {
-    sys_sleep, 
-    sys_puts, 
-    sys_gets, 
+    sys_sleep, // Syscall(0)
+    sys_puts,  // Syscall(1)
+    sys_gets,  // Syscall(2)
 };
 
 // int 0x80 - Syscall interrupt, handled by this function
@@ -50,7 +50,7 @@ void syscallHandler(void) {
     // We should also push these regs: ax, gs, fs, es, ds, bp, di, si, dx, cx, bx
     __asm__ volatile (
             ".intel_syntax noprefix\n" // We use intel syntax
-            ".equ MAX_SYSCALLS, 2\n" // Define MAX_SYSCALLS again
+            ".equ MAX_SYSCALLS, 3\n" // Define MAX_SYSCALLS again TODO: I don't want to have to do this
 
             // Check if syscall exists
             "cmp eax, MAX_SYSCALLS - 1\n"
@@ -82,7 +82,7 @@ void syscallHandler(void) {
             "pop fs\n"
             "pop gs\n"
             "add esp, 4\n" // Save eax value
-            "iretd\n" // Return from interrupt
+            "iretd\n" // Return from interrupt (32 bit)
 
             // TODO: Send an error or something here
             "invalidSyscall:\n"

include/keyboard/keyboard.h

@@ -43,8 +43,7 @@ char getc() {
 }
 
 // Reads until a newline
-char* read() {
-    static char inputBuffer[MAX_INPUT_LENGTH];
+void read(char* buffer) {
     char c;
     uint8_t len = 0;
 
@@ -54,15 +53,14 @@ char* read() {
             len--;
             putc(c);
         } else if (len + 1 != MAX_INPUT_LENGTH) { // Check if we can add a new character (this method avoids overflow issues)
-            inputBuffer[len++] = c;
+            buffer[len++] = c;
             putc(c);
         }
     }
 
-    inputBuffer[len++] = c; // Add newline
+    buffer[len++] = c; // Add newline
     putc(c);
-    inputBuffer[len] = '\0'; // Null terminate
-    return inputBuffer;
+    buffer[len] = '\0'; // Null terminate
 }
 
 void setupKeyboard() {

include/memory/addresses.h

@@ -3,5 +3,8 @@
 
 #define MEMMAP_AREA 0x30000
 #define KERNEL_LOC 0x50000
+#define FILETABLE_LOC 0x7000
+#define SMAP_ENTRY_COUNT 0x8500
+#define SMAP_ENTRIES 0x8504
 
 #endif

include/memory/virtual.h

@@ -16,7 +16,7 @@
 #define SET_ATTR(_entry, _attr) (*(_entry) |= (_attr))
 #define CLEAR_ATTR(_entry, _attr) (*(_entry) &= ~(_attr))
 #define TEST_ATTR(_entry, _attr) (*(_entry) & (_attr))
-#define SET_FRAME(_entry, _address) (*(_entry) = (*(_entry) & ~0x7ffff000) | (_address))
+#define SET_FRAME(_entry, _address) (*(_entry) = (*(_entry) & ~0xfffff000) | (_address))
 
 typedef uint32_t ptEntry_t;
 typedef uint32_t pdEntry_t;
@@ -96,13 +96,13 @@ void freePage(ptEntry_t* page) {
 }
 
 uint8_t setPageDirectory(pageDirectory_t* pd) {
-    if (!pd) { return 0; } // Nuh uh
+    if (!pd) { return 1; } // Nuh uh
     currentPd = pd;
     
     // cr3 (Control register 3) - current page dir address
     __asm__ volatile("movl %%eax, %%cr3" : : "a"(currentPd));
 
-    return 1; // Success
+    return 0; // Success
 }
 
 void flushTlbEntry(uint32_t virtualAddress) {
@@ -116,7 +116,7 @@ uint8_t mapPage(void* physicalAddr, void* virtualAddr) {
     if (!TEST_ATTR(entry, PTE_PRESENT)) {
         // Assuming that the page is not allocated since it's not present
         pageTable_t* table = (pageTable_t*)allocBlocks(1);
-        if (!table) return 0; // Out of memory!!
+        if (!table) return 1; // Out of memory!!
 
         // Clear page table (may be slow?)
         memset(table, 0, sizeof(pageTable_t));
@@ -134,7 +134,7 @@ uint8_t mapPage(void* physicalAddr, void* virtualAddr) {
     SET_ATTR(page, PTE_PRESENT);
     SET_FRAME(page, (uint32_t)physicalAddr);
 
-    return 1; // Success
+    return 0; // Success
 }
 
 void unmapPage(void* virtualAddress) {
@@ -148,7 +148,7 @@ uint8_t setupVirtualMemoryManager() {
     // Create a default page dir
     pageDirectory_t* dir = (pageDirectory_t*)allocBlocks(3);
     
-    if (!dir) { return 0; } // Out of memory
+    if (!dir) { return 1; } // Out of memory
 
     memset(dir, 0, sizeof(pageDirectory_t));
     for (uint32_t i = 0; i < 1024; i++) {
@@ -157,11 +157,11 @@ uint8_t setupVirtualMemoryManager() {
 
     // Alloc default page table
     pageTable_t* table = (pageTable_t*)allocBlocks(1);
-    if (!table) { return 0; } // Out of memory
+    if (!table) { return 1; } // Out of memory
     
     // Alloc a 3GB page
     pageTable_t* table3gb = (pageTable_t*)allocBlocks(1);
-    if (!table) { return 0; } // Out of memory
+    if (!table) { return 1; } // Out of memory
 
     memset(table, 0, sizeof(pageTable_t));
     memset(table3gb, 0, sizeof(pageTable_t));
@@ -200,7 +200,7 @@ uint8_t setupVirtualMemoryManager() {
 
     // ENABLE PAGING!!! Set PG bit 31 and PE bit 0 in cr0
     __asm__ volatile("movl %cr0, %eax; orl $0x80000001, %eax; movl %eax, %cr0");
-    return 1;
+    return 0; // Success
 }
 
 #endif