新增libc实现

apps/include/ctype.h

@@ -0,0 +1,18 @@
+#ifndef CRASHPOWEROS_CTYPE_H
+#define CRASHPOWEROS_CTYPE_H
+
+int ispunct(char ch);
+char toupper(char ch);
+char tolower(char ch);
+int iscsymf(int ch);
+int isascll(char ch);
+int iscntrl(char ch);
+int isxdigit(int c);
+int isspace(int c);
+int isdigit(int c);
+int isalpha(int c);
+int isupper(int c);
+int isprint(int c);
+int isgraph(int c);
+
+#endif

apps/include/libc.h

@@ -1,4 +0,0 @@
-#ifndef CRASHPOWEROS_LIBC_H
-#define CRASHPOWEROS_LIBC_H
-
-#endif

apps/include/math.h

@@ -0,0 +1,19 @@
+#ifndef CRASHPOWEROS_MATH_H
+#define CRASHPOWEROS_MATH_H
+
+#define MIN(i, j) (((i) < (j)) ? (i) : (j))
+#define MAX(i, j) (((i) > (j)) ? (i) : (j))
+
+#include <stdint.h>
+
+void srandlevel(unsigned short randlevel_);
+void smax(unsigned short max_b);
+void srand(unsigned long long seed);
+const unsigned long long rand();
+int32_t abs(int32_t x);
+double pow(double a,long long b);
+unsigned long long ull_pow(unsigned long long a,unsigned long long b);
+double sqrt(double x);
+float q_sqrt(float number);
+
+#endif

apps/include/stdio.h

@@ -1,13 +1,42 @@
 #ifndef CRASHPOWEROS_STDIO_H
 #define CRASHPOWEROS_STDIO_H
 
+#define EOF -1
+#define CANREAD(flag) ((flag)&READ || (flag)&PLUS)
+#define CANWRITE(flag) ((flag)&WRITE || (flag)&PLUS || (flag)&APPEND)
+#define READ 0x2
+#define WRITE 0x4
+#define APPEND 0x8
+#define BIN 0x0
+#define PLUS 0x10
+
 #include <stdint.h>
 #include <stddef.h>
 #include <stdarg.h>
 
+typedef struct FILE {
+    unsigned int mode;
+    unsigned int fileSize;
+    unsigned char *buffer;
+    unsigned int bufferSize;
+    unsigned int p;
+    char *name;
+} FILE;
+
 void put_char(char a);
 int printf(const char* fmt, ...);
 int puts(const char *s);
 int vsprintf(char *buf, const char *fmt, va_list args);
+int fgetc(FILE *stream);
+FILE *fopen(char *filename, char *mode);
+unsigned int fread(void *buffer, unsigned int size, unsigned int count,
+                   FILE *stream);
+int fclose(FILE *fp);
+char *fgets(char *str, int n, FILE *stream);
+int fputs(const char *str, FILE *stream);
+int fprintf(FILE *stream, const char *format, ...);
+int fputc(int ch, FILE *stream);
+unsigned int fwrite(const void *ptr, unsigned int size, unsigned int nmemb,
+                    FILE *stream);
 
 #endif

apps/include/stdlib.h

@@ -0,0 +1,12 @@
+#ifndef CRASHPOWEROS_STDLIB_H
+#define CRASHPOWEROS_STDLIB_H
+
+#include <stddef.h>
+
+long long atoi(const char* s);
+void *malloc(size_t size);
+void free(void *ptr);
+void exit(int code);
+void *realloc(void *ptr, uint32_t size);
+
+#endif

apps/include/string.h

@@ -2,15 +2,23 @@
 #define CRASHPOWEROS_STRING_H
 
 #include <stddef.h>
+#include <stdint.h>
 
-int isspace(int c);
-int isdigit(int c);
-int isalpha(int c);
-int isupper(int c);
-size_t strnlen(const char *s, size_t maxlen);
+const char* memchr(const char* buf,char c,unsigned long long count);
+void *memmove(void *dest, const void *src, size_t num);
+void *memset(void *s, int c, size_t n);
+int memcmp(const void *a_, const void *b_, uint32_t size);
+
+void* memcpy(void* s, const void* ct, size_t n);
 size_t strlen(const char *str);
 int strcmp(const char *s1, const char *s2);
 char *strcpy(char *dest, const char *src);
 char *strcat(char *dest, const char *src);
+const char* strstr(const char *str1,const char *str2);
+char *strdup(const char *str);
+
+char* strncat(char* dest,const char* src,unsigned long long count);
+size_t strnlen(const char *s, size_t maxlen);
+char* strncpy(char* dest, const char* src,unsigned long long count);
 
 #endif

apps/include/syscall.h

@@ -9,6 +9,9 @@
 #define SYSCALL_EXIT 6
 #define SYSCALL_G_CLEAN 7
 #define SYSCALL_GET_CD 8
+#define SYSCALL_VFS_FILESIZE 9
+#define SYSCALL_VFS_READFILE 10
+#define SYSCALL_VFS_WRITEFILE 11
 
 #include <stdint.h>
 #include <stddef.h>
@@ -21,5 +24,8 @@ void syscall_free(void *ptr);
 void syscall_exit(int code);
 void syscall_g_clean();
 void syscall_get_cd(char *buffer);
+int syscall_vfs_filesize(char* filename);
+void syscall_vfs_readfile(char* filename,char* buffer);
+void syscall_vfs_writefile(char* filename,char* buffer,unsigned int size);
 
 #endif

apps/libs/libc.c

@@ -1,13 +1,228 @@
 #include "../include/stdio.h"
 #include "../include/syscall.h"
+#include "../include/stdlib.h"
+#include "../include/string.h"
+
+void *malloc(size_t size){
+    return syscall_malloc(size);
+}
+
+void free(void *ptr){
+    syscall_free(ptr);
+}
+
+void exit(int code){
+    syscall_exit(code);
+}
+
+void *realloc(void *ptr, uint32_t size) {
+    void *new = malloc(size);
+    if (ptr) {
+        memcpy(new, ptr, *(int *)((int)ptr - 4));
+        free(ptr);
+    }
+    return new;
+}
+
+long long atoi(const char* s){
+    long long temp = 0,sign = (*s <= '9' && *s >= '0') ;
+    while(*s > '9' || *s < '0')s ++ ;
+    if(temp == 0 && *(s - 1) == '-')sign = -1 ;
+    else sign = 1 ;
+    while(*s <= '9' && *s >= '0')temp = (temp * 10) + (*s - '0') , s ++ ;
+    return sign * temp ;
+}
 
 void put_char(char c){
     syscall_putchar(c);
 }
 
+
+int fputc(int ch, FILE *stream) {
+    if (CANWRITE(stream->mode)) {
+        //		printk("Current Buffer=%s\n",stream->buffer);
+        if (stream->p >= stream->bufferSize) {
+            //	printk("Realloc....(%d,%d)\n",stream->p,stream->bufferSize);
+            stream->buffer = realloc(stream->buffer, stream->bufferSize + 100);
+            stream->bufferSize += 100;
+        }
+        if (stream->p >= stream->fileSize) {
+            stream->fileSize++;
+        }
+        //		printk("Current Buffer=%s(A)\n",stream->buffer);
+        stream->buffer[stream->p++] = ch;
+        //	printk("Current Buffer=%s(B)\n",stream->buffer);
+        return ch;
+    }
+    return EOF;
+}
+
+unsigned int fwrite(const void *ptr, unsigned int size, unsigned int nmemb,
+                    FILE *stream) {
+    if (CANWRITE(stream->mode)) {
+        unsigned char *c_ptr = (unsigned char *)ptr;
+        for (int i = 0; i < size * nmemb; i++) {
+            fputc(c_ptr[i], stream);
+        }
+        return nmemb;
+    } else {
+        return 0;
+    }
+}
+
+FILE *fopen(char *filename, char *mode) {
+    unsigned int flag = 0;
+    FILE *fp = (FILE *)malloc(sizeof(FILE));
+    while (*mode != '\0') {
+        switch (*mode) {
+            case 'a':
+                flag |= APPEND;
+                break;
+            case 'b':
+                break;
+            case 'r':
+                flag |= READ;
+                break;
+            case 'w':
+                flag |= WRITE;
+                break;
+            case '+':
+                flag |= PLUS;
+                break;
+            default:
+                break;
+        }
+        mode++;
+    }
+    if (syscall_vfs_filesize(filename) == -1) {
+        free(fp);
+        return NULL; // 找不到
+    } else if (flag & WRITE) {
+        char buffe2[100];
+    }
+    if (flag & WRITE) {
+        fp->fileSize = 0;
+    } else {
+        fp->fileSize = syscall_vfs_filesize(filename);
+    }
+    fp->bufferSize = 0;
+    if (flag & READ || flag & PLUS || flag & APPEND) {
+        fp->bufferSize = syscall_vfs_filesize(filename);
+    }
+    if (flag & WRITE || flag & PLUS || flag & APPEND) {
+        fp->bufferSize += 100;
+    }
+    if (fp->bufferSize == 0) {
+        fp->bufferSize = 1;
+    }
+    fp->buffer = malloc(fp->bufferSize);
+    if (flag & PLUS || flag & APPEND || flag & READ) {
+        //	printk("ReadFile........\n");
+        syscall_vfs_readfile(filename, fp->buffer);
+    }
+    fp->p = 0;
+    if (flag & APPEND) {
+        fp->p = fp->fileSize;
+    }
+    fp->name = malloc(strlen(filename) + 1);
+    strcpy(fp->name, filename);
+    fp->mode = flag;
+    return fp;
+}
+
+int fgetc(FILE *stream) {
+    if (CANREAD(stream->mode)) {
+        if (stream->p >= stream->fileSize) {
+            return EOF;
+        } else {
+            return stream->buffer[stream->p++];
+        }
+    } else {
+        return EOF;
+    }
+}
+
+unsigned int fread(void *buffer, unsigned int size, unsigned int count,
+                   FILE *stream) {
+    if (CANREAD(stream->mode)) {
+        unsigned char *c_ptr = (unsigned char *)buffer;
+        for (int i = 0; i < size * count; i++) {
+            unsigned int ch = fgetc(stream);
+            if (ch == EOF) {
+                return i;
+            } else {
+                c_ptr[i] = ch;
+            }
+        }
+        return count;
+    } else {
+        return 0;
+    }
+}
+
+int fclose(FILE *fp) {
+    if (fp == NULL) {
+        return EOF;
+    }
+    if (CANWRITE(fp->mode)) {
+        syscall_vfs_writefile(fp->name, fp->buffer, fp->fileSize);
+    }
+    free(fp->buffer);
+    free(fp->name);
+    free(fp);
+    return 0;
+}
+
+char *fgets(char *str, int n, FILE *stream) {
+    if (CANREAD(stream->mode)) {
+        for (int i = 0; i < n; i++) {
+            unsigned int ch = fgetc(stream);
+            if (ch == EOF) {
+                if (i == 0) {
+                    return NULL;
+                } else {
+                    break;
+                }
+            }
+            if (ch == '\n') {
+                break;
+            }
+            str[i] = ch;
+        }
+        return str;
+    }
+    return NULL;
+}
+
+int fputs(const char *str, FILE *stream) {
+    if (CANWRITE(stream->mode)) {
+        for (int i = 0; i < strlen(str); i++) {
+            fputc(str[i], stream);
+        }
+        return 0;
+    }
+    return EOF;
+}
+
+int fprintf(FILE *stream, const char *format, ...) {
+    if (CANWRITE(stream->mode)) {
+        int len;
+        va_list ap;
+        va_start(ap, format);
+        char *buf = malloc(1024);
+        len = vsprintf(buf, format, ap);
+        fputs(buf, stream);
+        free(buf);
+        va_end(ap);
+        return len;
+    } else {
+        return EOF;
+    }
+}
+
 void _start(){
-    extern int main();
-    int ret = main();
-    syscall_exit(ret);
+    extern int main(int argc,char** argv);
+    int ret = main(0,NULL);
+    exit(ret);
     while (1);
 }

apps/libs/math.c

@@ -0,0 +1,77 @@
+#include "../include/math.h"
+
+static unsigned long long rand_seed = 1 ;
+static unsigned short max_bit = 32 ;
+static unsigned short randlevel = 1 ;
+
+const unsigned long long rand(){
+    unsigned short i = 0;
+    while(i < randlevel)
+        rand_seed = rand_seed * 1103515245 + 12345 , rand_seed <<= max_bit , i ++ ;
+    return (const unsigned long long)(rand_seed >>= max_bit) ;
+}
+
+void srand(unsigned long long seed){
+    rand_seed = seed ;
+}
+
+void smax(unsigned short max_b){
+    max_b = (sizeof(unsigned long long) * 8) - (max_b % (sizeof(unsigned long long) * 8)) ;
+    max_bit = (max_b == 0) ? (sizeof(unsigned long long) * 8 / 2) : (max_b) ;
+}
+
+void srandlevel(unsigned short randlevel_){
+    if(randlevel_ != 0)
+        randlevel = randlevel_ ;
+}
+
+int32_t abs(int32_t x){
+    return (x < 0) ? (-x) : (x) ;
+}
+
+double pow(double a,long long b){
+    char t = 0 ;
+    if(b < 0)b = -b , t = 1 ;
+    double ans = 1 ;
+    while(b){
+        if(b & 1)ans *= a ;
+        a *= a ;
+        b >>= 1 ;
+    }
+    if(t)return (1.0 / ans) ;
+    else return ans ;
+}
+
+//快速整数平方
+unsigned long long ull_pow(unsigned long long a,unsigned long long b){
+    unsigned long long ans = 1 ;
+    while(b){
+        if(b & 1)ans *= a ;
+        a *= a ;
+        b >>= 1 ;
+    }
+    return ans ;
+}
+
+
+double sqrt(double x){
+    if(x == 0)return 0.0 ;
+    double xk = 1.0,xk1 = 0.0 ;
+    while(xk != xk1)xk1 = xk , xk = (xk + x / xk) / 2.0 ;
+    return xk ;
+}
+
+//快速求算数平方根（速度快，精度低）
+float q_sqrt(float number){
+    long i ;
+    float x,y ;
+    const float f = 1.5F ;
+    x = number * 0.5F ;
+    y = number ;
+    i = *(long*)(&y) ;
+    i = 0x5f3759df - (i >> 1) ;
+    y = *(float*)(&i) ;
+    y = y * (f - (x * y * y)) ;
+    y = y * (f - (x * y * y)) ;
+    return number * y ;
+}

apps/libs/string.c

@@ -1,25 +1,76 @@
 #include "../include/string.h"
+#include "../include/ctype.h"
+#include "../include/stdlib.h"
+
+int ispunct(char ch) {
+    return ch == '!' || ch == '@' || ch == '#' || ch == '$' || ch == '%' || ch == '^' || ch == '&' || ch == '*' ||
+           ch == '(' || ch == ')' || ch == '+' || ch == '-' || ch == '/' || ch == '?' || ch == '"' || ch == '\'' ||
+           ch == ':' || ch == ';' || ch == '{' || ch == '[' || ch == ']' || ch == '}' || ch == '|' || ch == '\\' ||
+           ch == '~' || ch == '`' || ch == '<' || ch == '>' || ch == ',' || ch == '.';
+}
+
+char toupper(char ch) {
+    return (ch & 0xDF);
+}
+
+char tolower(char ch) {
+    return (ch | 0x20);
+}
+
+int iscsymf(int ch) {
+    return ch == '_' || isdigit(ch) || isalpha(ch);
+}
+
+int isascll(char ch) {
+    return ((ch & 0x80) == 0);
+}
+
+int iscntrl(char ch) {
+    return ((ch == 0x7F) || (ch >= 0x00 && ch <= 0x1F));
+}
+
+int isprint(int c) {
+    return (c > 0x1F && c < 0x7F);
+}
+
+int isgraph(int c) {
+    return (c > 0x20 && c < 0x7F);
+}
+
+int isxdigit(int c) {
+    if (!((c >= 'a' && c <= 'f') || (c >= 'A' && c <= 'F'))) {
+        if (!isdigit(c)) return 0;
+    }
+    return 1;
+}
 
 int isspace(int c) {
     return (c == ' ' || c == '\t' || c == '\n' || c == '\r' || c == '\f' ||
             c == '\v');
 }
 
-// isdigit
 int isdigit(int c) {
     return (c >= '0' && c <= '9');
 }
 
-// isalpha
 int isalpha(int c) {
     return (c >= 'a' && c <= 'z') || (c >= 'A' && c <= 'Z');
 }
 
-// isupper
 int isupper(int c) {
     return (c >= 'A' && c <= 'Z');
 }
 
+const char *memchr(const char *buf, char c, unsigned long long count) {
+    while (count) {
+        if (*buf == c)
+            return buf;
+        ++count;
+        ++buf;
+    }
+    return 0;
+}
+
 size_t strnlen(const char *s, size_t maxlen) {
     const char *es = s;
     while (*es && maxlen) {
@@ -72,4 +123,92 @@ char *strcat(char *dest, const char *src) {
     while (*temp != '\0')
         temp++;
     while ((*temp++ = *src++) != '\0');
+}
+
+void *memcpy(void *s, const void *ct, size_t n) {
+    if (NULL == s || NULL == ct || n <= 0)
+        return NULL;
+    while (n--)
+        *(char *) s++ = *(char *) ct++;
+    return s;
+}
+
+int memcmp(const void *a_, const void *b_, uint32_t size) {
+    const char *a = a_;
+    const char *b = b_;
+    while (size-- > 0) {
+        if (*a != *b) return *a > *b ? 1 : -1;
+        a++, b++;
+    }
+    return 0;
+}
+
+void *memset(void *s, int c, size_t n) {
+    unsigned char *p = s;
+    while (n-- > 0)
+        *p++ = c;
+    return s;
+}
+
+void *memmove(void *dest, const void *src, size_t num) {
+    void *ret = dest;
+    if (dest < src) {
+        while (num--)//前->后
+        {
+            *(char *) dest = *(char *) src;
+            dest = (char *) dest + 1;
+            src = (char *) src + 1;
+        }
+    } else {
+        while (num--)//后->前
+        {
+            *((char *) dest + num) = *((char *) src + num);
+        }
+    }
+    return ret;
+}
+
+char *strncat(char *dest, const char *src, unsigned long long count) {
+    if (dest == 0 || src == 0)return 0;
+    char *ret = dest;
+    while (*dest != '\0')dest++;
+    for (unsigned long long i = 0; i < count; ++i)dest[i] = src[i];
+    dest[count] = '\0';
+    return ret;
+}
+
+char *strncpy(char *dest, const char *src, unsigned long long count) {
+    if (dest == 0 || src == 0)return 0;
+    char *ret = dest;
+    while (count)*dest = *src, ++dest, ++src, --count;
+    return ret;
+}
+
+const char *strstr(const char *str1, const char *str2) {
+    if (str1 == 0 || str2 == 0)return 0;
+    const char *temp = 0;
+    const char *res = 0;
+    while (*str1 != '\0') {
+        temp = str1;
+        res = str2;
+        while (*temp == *res)++temp, ++res;
+        if (*res == '\0')return str1;
+        ++str1;
+    }
+    return 0;
+}
+
+char *strdup(const char *str) {
+    if (str == NULL)
+        return NULL;
+
+    char *strat = (char *) str;
+    int len = 0;
+    while (*str++ != '\0')
+        len++;
+    char *ret = (char *) malloc(len + 1);
+
+    while ((*ret++ = *strat++) != '\0') {}
+
+    return ret - (len + 1);
 }

apps/libs/syscall.c

@@ -52,4 +52,32 @@ void syscall_get_cd(char *buffer){
     uint32_t __arg1 = (uint32_t)(buffer);
     register uint32_t ebx asm("ebx")  = __arg1;
     asm volatile("int $31\n\t" : "=a"(rets) : "0"(SYSCALL_GET_CD), "r"(ebx) : "memory", "cc");
+}
+
+int syscall_vfs_filesize(char* filename){
+    uint32_t rets;
+    uint32_t __arg1 = (uint32_t)(filename);
+    register uint32_t ebx asm("ebx")  = __arg1;
+    asm volatile("int $31\n\t" : "=a"(rets) : "0"(SYSCALL_VFS_FILESIZE), "r"(ebx) : "memory", "cc");
+    return rets;
+}
+
+void syscall_vfs_readfile(char* filename,char* buffer){
+    uint32_t rets;
+    uint32_t __arg1 = (uint32_t)(filename);
+    uint32_t __arg2 = (uint32_t)(buffer);
+    register uint32_t ebx asm("ebx") = __arg1;
+    register uint32_t ecx asm("ecx") = __arg2;
+    asm volatile("int $31\n\t" : "=a"(rets) : "0"(SYSCALL_VFS_READFILE), "r"(ebx), "r"(ecx) : "memory", "cc");
+}
+
+void syscall_vfs_writefile(char* filename,char* buffer,unsigned int size){
+    uint32_t rets;
+    uint32_t __arg1 = (uint32_t)(filename);
+    uint32_t __arg2 = (uint32_t)(buffer);
+    uint32_t __arg3 = (uint32_t)(size);
+    register uint32_t ebx asm("ebx") = __arg1;
+    register uint32_t ecx asm("ecx") = __arg2;
+    register uint32_t edx asm("edx") = __arg3;
+    asm volatile("int $31\n\t" : "=a"(rets) : "0"(SYSCALL_VFS_FILESIZE), "r"(ebx), "r"(ecx), "r"(edx) : "memory", "cc");
 }

apps/shell/shell.c

@@ -9,7 +9,7 @@ static int gets(char *buf, int buf_size) {
         if (c == '\b') {
             if (index > 0) {
                 index--;
-                syscall_print("\b \b");
+                printf("\b \b");
             }
         } else {
             buf[index++] = c;
@@ -72,7 +72,7 @@ int main(){
             printf("mkdir      <name>     Make a directory.\n");
             printf("del rm     <name>     Delete a file.\n");
             printf("sysinfo               Print system info.\n");
-            printf("proc [kill<pid>|list] Lists all running processes.\n");
+            printf("proc [kill<pid>|list] List all running processes.\n");
             printf("reset                 Reset OS.\n");
             printf("shutdown exit         Shutdown OS.\n");
             printf("debug                 Print os debug info.\n");

src/include/pagehead.h

@@ -0,0 +1,12 @@
+#ifndef CRASHPOWEROS_PAGEHEAD_H
+#define CRASHPOWEROS_PAGEHEAD_H
+
+#include <stdint.h>
+#include <stddef.h>
+
+void *page_sbrk(int incr);
+void *page_alloc(size_t size);
+void page_free(void *block);
+void *page_malloc(size_t size,uint32_t *phys);
+
+#endif

src/include/syscall.h

@@ -13,6 +13,9 @@
 #define SYSCALL_EXIT 6
 #define SYSCALL_G_CLEAN 7
 #define SYSCALL_GET_CD 8
+#define SYSCALL_VFS_FILESIZE 9
+#define SYSCALL_VFS_READFILE 10
+#define SYSCALL_VFS_WRITEFILE 11
 
 void syscall_install();
 

src/kernel/page.c

@@ -3,6 +3,7 @@
 #include "../include/io.h"
 #include "../include/task.h"
 #include "../include/timer.h"
+#include "../include/pagehead.h"
 
 page_directory_t *kernel_directory = 0; // 内核用页目录
 page_directory_t *current_directory = 0; // 当前页目录
@@ -14,6 +15,7 @@ extern struct task_struct *current;
 
 extern uint32_t placement_address;
 extern void *program_break, *program_break_end;
+extern void *page_break, *page_end;
 
 static void set_frame(uint32_t frame_addr) {
     uint32_t frame = frame_addr / 0x1000;
@@ -169,6 +171,7 @@ void page_fault(registers_t *regs) {
 
 static page_table_t *clone_table(page_table_t *src, uint32_t *physAddr) {
     page_table_t *table = (page_table_t *) kmalloc_i_ap(sizeof(page_table_t), physAddr);
+
     memset(table, 0, sizeof(page_directory_t));
 
     int i;
@@ -210,8 +213,11 @@ page_directory_t *clone_directory(page_directory_t *src) {
 }
 
 void init_page(multiboot_t *mboot) {
-    uint32_t mem_end_page = 0xFFFFFFFF; // 4GB Page
 
+    page_break = placement_address;
+    page_end = placement_address + 0x50000;
+
+    uint32_t mem_end_page = 0xFFFFFFFF; // 4GB Page
     nframes = mem_end_page / 0x1000;
     frames = (uint32_t *) kmalloc(INDEX_FROM_BIT(nframes));
     memset(frames, 0, INDEX_FROM_BIT(nframes));

src/kernel/pagehead.c

@@ -0,0 +1,81 @@
+#include "../include/pagehead.h"
+#include "../include/memory.h"
+
+void *page_break, *page_end;
+header_t *page_head;
+header_t *page_tail;
+extern void *program_break;
+extern page_directory_t *kernel_directory;
+
+static header_t *page_get_free_block(size_t size) {
+    header_t *curr = page_head;
+    while (curr) {
+        if (curr->s.is_free && curr->s.size >= size) return curr;
+        curr = curr->s.next;
+    }
+    return NULL;
+}
+
+void *page_sbrk(int incr) {
+    if (page_break + incr >= (page_end)) return (void *) -1;
+    void *prev_break = page_break;
+    page_break += incr;
+    return prev_break;
+}
+
+void *page_malloc(size_t size,uint32_t *phys){
+    void *addr = page_alloc(size);
+    *phys = addr;
+    if (program_break) {
+        if (phys) {
+            page_t *page = get_page((uint32_t) addr, 0, kernel_directory,false);
+            *phys = page->frame * 0x1000 + ((uint32_t) addr & 0x00000FFF);
+        }
+    }
+    return (uint32_t) addr;
+}
+
+void *page_alloc(size_t size) {
+    uint32_t total_size;
+    void *block;
+    header_t *header;
+    if (!size) return NULL;
+    header = page_get_free_block(size);
+    if (header) {
+        header->s.is_free = 0;
+        return (void *) (header + 1);
+    }
+    total_size = sizeof(header_t) + size;
+    block = page_sbrk(total_size);
+    if (block == (void *) -1) return NULL;
+    header = block;
+    header->s.size = size;
+    header->s.is_free = 0;
+    header->s.next = NULL;
+    if (!page_head) page_head = header;
+    if (page_tail) page_tail->s.next = header;
+    page_tail = header;
+    return (void *) (header + 1);
+}
+
+void page_free(void *block) {
+    header_t *header, *tmp;
+    if (!block) return;
+    header = (header_t *) block - 1;
+    if ((char *) block + header->s.size == page_break) {
+        if (page_head == page_tail)page_head = page_tail = NULL;
+        else {
+            tmp = page_head;
+            while (tmp) {
+                if (tmp->s.next == page_tail) {
+                    tmp->s.next = NULL;
+                    page_tail = tmp;
+                }
+                tmp = tmp->s.next;
+            }
+        }
+        page_sbrk(0 - sizeof(header_t) - header->s.size);
+        return;
+    }
+    header->s.is_free = 1;
+}

src/kernel/syscall.c

@@ -7,6 +7,7 @@
 #include "../include/shell.h"
 #include "../include/heap.h"
 #include "../include/keyboard.h"
+#include "../include/vfs.h"
 
 static void syscall_puchar(uint32_t ebx,uint32_t ecx,uint32_t edx,uint32_t esi,uint32_t edi){
     printf("%c",ebx);
@@ -47,6 +48,18 @@ static void syscall_get_cd(uint32_t ebx,uint32_t ecx,uint32_t edx,uint32_t esi,u
     else buf = "nofs";
 }
 
+static int syscall_vfs_filesize(uint32_t ebx,uint32_t ecx,uint32_t edx,uint32_t esi,uint32_t edi){
+    return vfs_filesize(ebx);
+}
+
+static void syscall_vfs_readfile(uint32_t ebx,uint32_t ecx,uint32_t edx,uint32_t esi,uint32_t edi){
+    vfs_readfile(ebx,ecx);
+}
+
+static void syscall_vfs_writefile(uint32_t ebx,uint32_t ecx,uint32_t edx,uint32_t esi,uint32_t edi){
+    vfs_writefile(ebx,ecx,edx);
+}
+
 void *sycall_handlers[MAX_SYSCALLS] = {
         [SYSCALL_PUTC] = syscall_puchar,
         [SYSCALL_PRINT] = syscall_print,
@@ -56,6 +69,9 @@ void *sycall_handlers[MAX_SYSCALLS] = {
         [SYSCALL_EXIT] = syscall_exit,
         [SYSCALL_G_CLEAN] = syscall_g_clean,
         [SYSCALL_GET_CD] = syscall_get_cd,
+        [SYSCALL_VFS_FILESIZE] = syscall_vfs_filesize,
+        [SYSCALL_VFS_READFILE] = syscall_vfs_readfile,
+        [SYSCALL_VFS_WRITEFILE] = syscall_vfs_writefile,
 };
 
 typedef size_t (*syscall_t)(size_t, size_t, size_t, size_t, size_t);