feat: Vfs and Ext2 support. Code style/attribute improvements

Added VFS and Ext2 support.
Optimized attributes of methods to improve code highlighting.
Printf attribute, malloc attribute, etc.

rootfs/.gitignore

@@ -0,0 +1,3 @@
+mnt/*
+!mnt
+rootfs.img

rootfs/mkrootfs.sh

@@ -0,0 +1,52 @@
+#!/bin/bash
+
+IMG_FILE=rootfs.img
+IMG_SIZE=100 # MB
+
+function log() {
+  echo "$*"
+}
+
+function yes_or_no() {
+  while true; do
+    read -p "$* [y/n]: " yn
+    case $yn in
+    [Yy]*) return 0 ;;
+    [Nn]*)
+      echo "Aborted"
+      return 1
+      ;;
+    esac
+  done
+}
+
+function setup_lb() {
+  sudo losetup -fP --show ${IMG_FILE}
+}
+
+if [ ! -d mnt ]; then
+  mkdir mnt
+fi
+
+if [ -f "${IMG_FILE}" ]; then
+  log "${IMG_FILE} already exists"
+  if ! yes_or_no "Continue?"; then
+    exit 1
+  fi
+fi
+
+# build img
+dd if=/dev/zero of=${IMG_FILE} bs=1M count=${IMG_SIZE}
+
+parted -s ${IMG_FILE} mktable msdos
+parted -s ${IMG_FILE} mkpart primary ext2 0 100%
+
+LB_DEV="$(setup_lb)"
+
+if [ -z "${LB_DEV}" ]; then
+  log "Failed to setup loobback"
+  exit 1
+fi
+
+sudo mkfs.ext2 -L rootfs "${LB_DEV}p1"
+sudo mount "${LB_DEV}p1" mnt

rootfs/mount_rootfs.sh

@@ -0,0 +1,39 @@
+#!/bin/bash
+
+IMG_FILE=rootfs.img
+IMG_SIZE=100 # MB
+
+function log() {
+  echo "$*"
+}
+
+function yes_or_no() {
+  while true; do
+    read -p "$* [y/n]: " yn
+    case $yn in
+    [Yy]*) return 0 ;;
+    [Nn]*)
+      echo "Aborted"
+      return 1
+      ;;
+    esac
+  done
+}
+
+function setup_lb() {
+  sudo losetup -fP --show ${IMG_FILE}
+}
+
+if [ ! -f "${IMG_FILE}" ]; then
+  log "${IMG_FILE} doesn't exist"
+  exit 1
+fi
+
+LB_DEV="$(setup_lb)"
+
+if [ -z "${LB_DEV}" ]; then
+  log "Failed to setup loobback"
+  exit 1
+fi
+
+sudo mount "${LB_DEV}p1" mnt

rootfs/umount_rootfsh.sh

@@ -0,0 +1,15 @@
+#!/bin/bash
+
+function log() {
+  echo "$*"
+}
+
+LB_DEV=$(findmnt -n -o SOURCE mnt)
+
+if [ -z "${LB_DEV}" ]; then
+  log "Not mounted"
+  exit 1
+fi
+
+sudo umount mnt
+sudo losetup -d "${LB_DEV%p1}"