How to install a root file system to a Hard Disk

First I want to let you know that you must have serial port installed to your DSM-G600! Also I want to let you know that getting a regular (Gentoo or Debian) linux work on DSM-G600 can be extremely hard and It is recommended that you have very good knowledge about how Gentoo and Debian really work (boot process, initrd, inittab, services, runlevels).

1. Install a serial console or look up loader.o method for kernel loading.
2. Install Gentoo chroot or a Debian chroot into sda3 root.
3. Get Kernel source.
4. Apply a kernel patch. After that your kernel is going to ignore U-Boot bootargs and you will be able to set a CONFIG_CMDLINE parameter.

   --- arch/ppc/kernel/setup.c.orig        2005-04-11 05:50:07.000000000 +0300
   +++ arch/ppc/kernel/setup.c     2007-02-17 16:06:16.000000000 +0200
   @@ -607,8 +611,8 @@
           init_mm.brk = (unsigned long) klimit;
    
           /* Save unparsed command line copy for /proc/cmdline */
   -       strcpy(saved_command_line, cmd_line);
   -       *cmdline_p = cmd_line;
   +       strcpy(saved_command_line, CONFIG_CMDLINE);
   +       *cmdline_p = CONFIG_CMDLINE;
    
           /* set up the bootmem stuff with available memory */
           do_init_bootmem();

5. Additional kernel .config entries you might want to add/change.

   CONFIG_CMDLINE_BOOL=y
   CONFIG_CMDLINE="root=/dev/sda3 console=ttyS0,9600"
   CONFIG_DEVFS_FS=y
   CONFIG_UNIX=y
   CONFIG_FILTER=y
   CONFIG_UNIX98_PTYS=y
   CONFIG_DEVPTS_FS=y
   # CONFIG_NTFS_FS is not set
   # CONFIG_NTFS_RW is not set
   # CONFIG_TULIP is not set

   If you want to also enable reiserfs then you need to disable NFS for example to get more space. Remember that maximum U-Boot formated kernel size is 936KB!

6. Guide for compiling kernel.
7. Guide for uploading new kernel or loading it with loader.o.

By default you don't need to do nothing with ramdisk. Ramdisk will be loaded into memory as usual. To go around this problem you can boot with bootm FFF10000 U-Boot parameter which will only load a kernel image. Also it may be convenient to replace the RAMDisk image at 0xFFC20000 by an empty U-Boot image, like this one (do not forget to uncompress it with gunzip(1)).

Forum thread
loader.o method without flashing