title: unable to login buildroot
body: <p>i use buildroot and compile linux kenrenl and when i run QEMU,i cann't login to builroot, because i cann't see message "Welcome to buildroot" for login,</p>
  
  <pre><code>ata2.01: NODEV after polling detection
  ata2.00: ATAPI: QEMU DVD-ROM, 2.5+, max UDMA/100
  ata1.01: NODEV after polling detection
  ata1.00: ATA-7: QEMU HARDDISK, 2.5+, max UDMA/100
  ata1.00: 11502 sectors, multi 16: LBA48 
  ata1.00: configured for MWDMA2
  ata2.00: configured for MWDMA2
  scsi 0:0:0:0: Direct-Access     ATA      QEMU HARDDISK    2.5+ PQ: 0 
  ANSI: 5
  sd 0:0:0:0: [sda] 11502 512-byte logical blocks: (5.89 MB/5.62 MiB)
  scsi 1:0:0:0: CD-ROM            QEMU     QEMU DVD-ROM     2.5+ PQ: 0 
  ANSI: 5
  sd 0:0:0:0: [sda] Write Protect is off
  sd 0:0:0:0: [sda] Mode Sense: 00 3a 00 00
  sd 0:0:0:0: [sda] Write cache: enabled, read cache: enabled, doesn't 
  support DPO or FUA
  sd 0:0:0:0: [sda] Attached SCSI disk
  input: ImExPS/2 Generic Explorer Mouse as 
  /devices/platform/i8042/serio1/input/input3
  EXT4-fs (sda): couldn't mount as ext3 due to feature incompatibilities
  EXT4-fs (sda): mounting ext2 file system using the ext4 subsystem
  EXT4-fs (sda): mounted filesystem without journal. Opts: (null)
  VFS: Mounted root (ext2 filesystem) readonly on device 8:0.
  devtmpfs: mounted
  Freeing unused kernel memory: 832K (ffffffff8186e000 - 
  ffffffff8193e000)
  Write protecting the kernel read-only data: 8192k
  Freeing unused kernel memory: 1212K (ffff8800014d1000 - 
  ffff880001600000)
  Freeing unused kernel memory: 536K (ffff88000177a000 - 
  ffff880001800000)
  random: fast init done
  EXT4-fs (sda): warning: mounting unchecked fs, running e2fsck is 
  recommended
  EXT4-fs (sda): re-mounted. Opts: 
  block_validity,barrier,user_xattr,errors=remount-ro
  Starting logging: OK
  Initializing random number generator... done.
  Starting network: OK
  
  ### here, i was unable to see message command for login,
  </code></pre>
  
  <p>QEMU:</p>
  
  <pre><code>qemu-system-x86_64 -hda buildroot/buildroot 2017.02.2/output/images/rootfs.ext2  -m 2G -smp 2 -nographic -kernel buildroot/buildroot-2017.02.2/output/images/bzImage -append "console=ttyS0 root=/dev/sda debug earlyprintk=serial slub_debug=QUZ"
  </code></pre>
  
  <p>i don't understand why i am unable to see message "Welcome to buildroot" ??</p>