Add empty vfs program and fix tar parsing

Makefile

@@ -20,17 +20,21 @@ debug: os.iso kernel.elf
 	@$(EMU) -s $(QFLAGS) &
 	@$(GDB) -ex "target remote localhost:1234" -ex "symbol-file kernel/kernel.elf"
 
-os.iso: kernel.elf initrd/* initrd/init
+os.iso: kernel.elf initrd/* initrd/init initrd/vfs
 	@cp kernel/kernel.elf iso/boot
 	@cd initrd; tar -f ../iso/boot/initrd.tar -c *
 	@grub-mkrescue -o $@ iso > /dev/null 2>/dev/null
 
-.PHONY: kernel.elf initrd/init
+.PHONY: kernel.elf initrd/init initrd/vfs
 
 initrd/init:
 	$(MAKE) -C init
 	cp init/init initrd/init
 
+initrd/vfs:
+	$(MAKE) -C vfs
+	cp vfs/vfs initrd/vfs
+
 kernel.elf:
 	@$(MAKE) -C kernel
 	@$(MAKE) -C libc

init/main.c

@@ -1,4 +1,4 @@
-#include "../libc/string.h"
+#include <string.h>
 #include "vga.h"
 #include <grub/text_fb_info.h>
 
@@ -40,10 +40,13 @@ int main(char* initrd, uint32_t initrd_sz) {
     if (hdr.filename[0]=='\0') break;
     uint32_t size=getsize(hdr.size);
     pos+=512;
-    if (strcmp(hdr.filename,"init")==0) {
-      vga_write_string("Init found");
+    if (strcmp(hdr.filename,"vfs")==0) {
+      vga_write_string("VFS found");
     }
     pos+=size;
+    if (pos%512!=0) {
+      pos+=512-(pos%512);
+    }
   }
   for (;;);
 }

kernel/kernel.c

@@ -71,6 +71,9 @@ void kmain(struct multiboot_boot_header_tag* hdr) {
       break;
     }
     pos+=size;
+    if (pos%512!=0) {
+      pos+=512-(pos%512);
+    }
   }
   elf_header header;
   pos=datapos;

vfs/Makefile

@@ -0,0 +1,14 @@
+C_SOURCES = $(wildcard *.c)
+OBJ = $(C_SOURCES:.c=.o ../kernel/start.o)
+CFLAGS = -I../sysroot/usr/include -Wall -g -ffreestanding
+CC = i386-elf-gcc
+
+vfs: $(OBJ)
+	@i386-elf-ld -o $@ $^ ../libc/libc.a
+	@rm -rf *.o
+
+%.o: %.c
+	@$(CC) $(CFLAGS)  -c $< -o $@
+
+clean:
+	@rm -rf *.o prog.elf

vfs/main.c

@@ -0,0 +1,3 @@
+int main() {
+  for (;;);
+}