trying to get VGA fb mode to work..

rocklibc/src/malloc.c

@@ -0,0 +1,74 @@
+#include <stdlib.h>
+#include <syscall.h>
+
+#define ALIGN(size) (((size) + 3) & ~3)
+#define HEADER_SIZE sizeof(struct Header)
+
+struct Header {
+    size_t size;
+    int is_free;
+    struct Header* next;
+};
+
+static struct Header* free_list_head = NULL;
+
+static struct Header* find_free_block(struct Header** last, size_t size) {
+    struct Header* current = free_list_head;
+    while (current && !(current->is_free && current->size >= size)) {
+        *last = current;
+        current = current->next;
+    }
+    return current;
+}
+
+static struct Header* request_space(struct Header* last, size_t size) {
+    struct Header* block = sbrk(0);
+    void* request = sbrk(size + HEADER_SIZE);
+    
+    if (request == (void*)-1) {
+        return NULL;
+    }
+    
+    if (last) {
+        last->next = block;
+    }
+    
+    block->size = size;
+    block->next = NULL;
+    block->is_free = 0;
+    return block;
+}
+
+void* malloc(size_t size) {
+    if (size <= 0) {
+        return NULL;
+    }
+    
+    size = ALIGN(size);
+    
+    if (free_list_head == NULL) {
+        struct Header* block = request_space(NULL, size);
+        if (!block) return NULL;
+        free_list_head = block;
+        return (void*)(block + 1);
+    }
+    
+    struct Header* last = free_list_head;
+    struct Header* block = find_free_block(&last, size);
+    
+    if (block) {
+        block->is_free = 0;
+    } else {
+        block = request_space(last, size);
+        if (!block) return NULL;
+    }
+    
+    return (void*)(block + 1);
+}
+
+void free(void* ptr) {
+    if (!ptr) return;
+    
+    struct Header* block = (struct Header*)ptr - 1;
+    block->is_free = 1;
+}

rocklibc/src/strcat.c

@@ -0,0 +1,8 @@
+#include <string.h>
+#include <stdint.h>
+
+char* strcat(char* dest, const char* src) {
+    char* start = dest + strlen(dest);
+    strcpy(start, src);
+    return dest;
+}

rocklibc/src/strtok.c

@@ -0,0 +1,63 @@
+#include <string.h>
+
+static size_t kernel_strspn(const char *s, const char *accept) {
+    const char *p;
+    const char *a;
+    size_t count = 0;
+
+    for (p = s; *p != '\0'; ++p) {
+        for (a = accept; *a != '\0'; ++a) {
+            if (*p == *a)
+                break;
+        }
+        if (*a == '\0')
+            return count;
+        ++count;
+    }
+    return count;
+}
+
+static char *kernel_strpbrk(const char *s, const char *accept) {
+    while (*s != '\0') {
+        const char *a = accept;
+        while (*a != '\0') {
+            if (*s == *a) {
+                return (char *)s;
+            }
+            a++;
+        }
+        s++;
+    }
+    return NULL;
+}
+
+char *strtok_r(char *str, const char *delim, char **saveptr) {
+    char *token;
+
+    if (str == NULL) {
+        str = *saveptr;
+    }
+
+    if (str == NULL || *str == '\0') {
+        *saveptr = NULL;
+        return NULL;
+    }
+
+    str += kernel_strspn(str, delim);
+    if (*str == '\0') {
+        *saveptr = NULL;
+        return NULL;
+    }
+
+    token = str;
+    str = kernel_strpbrk(token, delim);
+    
+    if (str == NULL) {
+        *saveptr = NULL;
+    } else {
+        *str = '\0';
+        *saveptr = str + 1;
+    }
+
+    return token;
+}

rocklibc/src/syscall.c

@@ -65,4 +65,12 @@ int dup2(int src, int dst) {
 
 int waitpid(int pid, int* status) {
     return syscall3(SYS_WAIT, pid, (uint32_t)status, 0);
+}
+
+void* sbrk(int32_t increment) {
+    return (void*)syscall1(SYS_SBRK, increment);
+}
+
+int brk(void *addr) {
+    return syscall1(SYS_BRK, (uint32_t)addr);
 }