[TadW]

So I poked around the sources a little bit, and here is what I've discovered so far (pardon the disorder, my mind sometimes works in mysterious ways):

• Lab126 is the developer (software, hardware?) of the Kindle (notice, it's now assimilated by the Amazon Borg) - hint: they are hiring
• Of particular interest: u-boot-1.1.2.tar.bz2 (contains boot loader code) and linux-2.6.10-lab126.tar.bz2 (obvious)
• The Kindle is referred to as the Fiona computer platform
• The u-boot code contains customized code for the Kindle; for example, it allows you to go into maintenance mode during booting (more about this later)
• Some packages not only contain source and header files, but also precompiled libraries: /u-boot-1.1.2/bml/xsr.a, /u-boot-1.1.2/common/cmd_util.a
• The Kindle is based on the older E Ink Apollo controller architecture (rather than the newer Metronome)
• /u-boot-1.1.2/board/fiona/recovery.S contains the code to step into recovery/diagnostics mode
• /u-boot-1.1.2/board/fiona/images contains images of various booting options (including recovery) in binary hex (gzipped content)
• /u-boot-1.1.2/common/main.c describes the booting sequence. Notice the important keys for initiating maintenance/diagnostic mode.
• Various board revisions of the Kindle exist. At one point, the power switch was a slide-switch as opposed to a toggle (see /linux-2.6.10/arch/arm/mach-pxa/fiona.c)
• AnyData DTEV dual modem module used for Sprint's wireless EVDO network
• Misc snippets:
  

  #ifdef CONFIG_ARCH_FIONA
  #define BOARD_SERIALNUM_SIZE  32

  //#define USER_DIAGNOSTIC_RAM_BASE    (0xA2000000-USER_DIAGNOSTIC_SIGNATURE_SIZE)
  #define USER_DIAGNOSTIC_RAM_BASE    0xA2000000
  #define USER_DIAGNOSTIC_CODE_ENTRY_PT   (USER_DIAGNOSTIC_RAM_BASE+USER_DIAGNOSTIC_SIGNATURE_OFFSET+USER_DIAGNOSTIC_SIGNATURE_SIZE)
  #define USER_DIAGNOSTIC_VECTOR_TABLE_ADDR (USER_DIAGNOSTIC_RAM_BASE+USER_DIAGNOSTIC_VECTOR_TABLE_OFFSET)
  
  #define CONFIG_RECOVER_CONSOLE_KEY    'R' // Force recovery bootloader into console.
  
  #define CONFIG_DIAGS_KEY      'D' // Go into diagnostics mode (if CONFIG_BOOT_DIAGS defined).
  #define CONFIG_DIAGS_IOC_KEY      0x23  // Key code for 'd'.
  
  #define CONFIG_FW_RESET_KEY     '?' // Force recovery bootloader to do a firmware reset.
  #define CONFIG_FW_RESET_IOC_KEY     0x27  // Key code for '/'
  
  #define CONFIG_SW_UPDATE_KEY      'U' // Force recovery bootloader to do a firmware update.
  #define CONFIG_SW_UPDATE_IOC_KEY    0x22  // Key code for 'u'.
  
  #define CONFIG_FACTORY_UPDATE_KEY   '%' // Force recovery bootloader to do a factory update.
  #define CONFIG_FACTORY_UPDATE_IOC_KEY   0x20  // Key code for '5'.
  
  #define CONFIG_MENU_SCROLL_IOC_KEY    0x07  // Force recovery bootloader into service menu.
  #define CONFIG_MENU_HOME_IOC_KEY    0x2F  // Force recovery bootloader into service menu.
  #define CONFIG_MENU_KEY       0x1B  // Force recovery bootloader into service menu (ESC, ^[).
  
  #define CONFIG_MENU_DIAG_BOOT_KEY   '0' // Service menu's diag selection key.
  #define CONFIG_MENU_DIAG_BOOT_IOC_KEY   0x19  // Key code for '0'.
  
  #define CONFIG_MENU_UPDATE_BOOT_KEY   '1' // Service menu's firware update selection key.
  #define CONFIG_MENU_UPDATE_BOOT_IOC_KEY   0x00  // Key code for '1'
  
  #define CONFIG_MENU_RESET_BOOT_KEY    '2' // Service menu's firmware reset selection key.
  #define CONFIG_MENU_RESET_BOOT_IOC_KEY    0x08  // Key code for '2'
  
  #define CONFIG_MENU_STANDARD_BOOT_KEY   '3' // Service menu's normal boot (exit) selection key.
  #define CONFIG_MENU_STANDARD_BOOT_IOC_KEY 0x10  // Key code for '3'

  static bool fiona_preserve_boot_key(void)
  {
      // Check to see whether the user has hit a key on either the
      // device or the console, and then decide what to do, depending
      // on the keys they've hit.
      //
      bool boot_key_preserved = true, console = false;
      int boot_key = get_boot_ioc_key();
  
      // The boot key is either an IOC key or it's coming from the
      // console.
      //
      if ( 0 == boot_key )
      {
          boot_key = get_boot_key();
          console = true;
      }
      else
      {
          // For device keys, we need to ensure that the key is still down
          // to prevent stray key presses on boot from snagging.
          //
          if ( !ioc_key_still_down(boot_key) )
              boot_key = 0;
      }