Here are the latest Biffboot CE versions. Please note the license has been changed, and is now as follows:The configuration area layout is as follows:
This Bootloader is copyright (c) 2014 Bifferos.com.
Permission is hereby granted, free of charge, to any person obtaining a copy
of this Bootloader to deal in the Bootloader without restriction, including
the rights to copy, publish, distribute sublicense, and/or sell copies of the
Bootloader and to permit persons to whom the Bootloader is furnished to do so,
subject to the following conditions:
Modification of the Bootloader binary is not permitted, excepting the 12-byte
configuration area found at offset 0xfff4.
THE SOFTWARE IS PROVIDED 'AS IS', WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
AUTHOR OR COPYRIGHT HOLDER BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY,
WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN
CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
Contact firstname.lastname@example.org if custom versions are required.
You can print this license from within biffboot with the 'license' command.
In order to use the binary, you will probably want to first change the MAC address in the configuration section at the end of the file, although if you have a serial cable, on entering the bootloader configuration system you will be invited to set a MAC address that will be one-time programmed to the board. If you never enter the config menus, or bail out of setting the MAC it remains at the default value of 00:01:02:03:04:05.
DW 0x2313 ; setting for etron SDRAM chip, use 0x2315 for old DRAM (pre 2014 boards).
DB 0x00 ; this will auto-detect memory size
DB 0xff ; unused, for future expansion
Pay attention to the buffer strength control register. The Etron DRAM chips that were being used from 2014 onwards require the setting of 0x2313 which is now the default. DRAM chips on the old boards used the value of 0x2315. Unfortunately there is no way to detect the DRAM characteristics as there is with the NOR flash, so this must be set right. If this value is wrong it will manifest itself as occasional memory errors. Use of the value 0x2313 with older boards has not been tested, so there's always a chance this new value will work with either board.