bfgminer/README.FPGA

This README contains extended details about FPGA mining with BFGMiner


ModMiner (MMQ)
--------------

The mining bitstream does not survive a power cycle, so BFGMiner will upload
it, if it needs to, before it starts mining (approx 3min)

The red LED also flashes while it is uploading the bitstream

-

If the MMQ doesn't respond to BFGMiner at all, or the red LED isn't flashing
then you will need to reset the MMQ.

The red LED should always be flashing when it is mining or ready to mine.

To reset the MMQ, you are best to press the left "RESET" button on the
backplane, then unplug and replug the USB cable.

If your MMQ doesn't have a button on the "RESET" pad, you need to join the two
left pads of the "RESET" pad with conductive wire to reset it. Cutting a small
(metal) paper-clip in half works well for this.

Then unplug the USB cable, wait for 5 seconds, then plug it back in.

After you press reset, the red LED near the USB port should blink continuously.

If it still wont work, power off, wait for 5 seconds, then power on the MMQ
This of course means it will upload the bitstream again when you start BFGMiner.

-

Device 0 is on the power end of the board.

-

You must make sure you have an appropriate firmware in your MMQ
Read here for official details of changing the firmware:
 http://wiki.btcfpga.com/index.php?title=Firmware

The basics of changing the firmware are:
 You need two short pieces of conductive wire if your MMQ doesn't have buttons
 on the "RESET" and "ISP" pads on the backplane board.
 Cutting a small (metal) paper-clip in half works well for this.

 Join the 2 left pads of the "RESET" pad with wire and the led will dim.
 Without disconnecting the "RESET", join the 2 left pads of the "ISP" pad with
 a wire and it will stay dim.
 Release "RESET" then release "ISP" and is should still be dim.
 Unplug the USB and when you plug it back in it will show up as a mass storage
 device.
  Linux: (as one single line):
   mcopy -i /dev/disk/by-id/usb-NXP_LPC134X_IFLASH_ISP000000000-0:0
      modminer091012.bin ::/firmware.bin
  Windows: delete the MSD device file firmware.bin and copy in the new one
   rename the new file and put it under the same name 'firmware.bin'
 Disconnect the USB correctly (so writes are flushed first)
 Join and then disconnect "RESET" and then plug the USB back in and it's done.

Best to update to one of the latest 2 listed below if you don't already
have one of them in your MMQ.

The current latest different firmware are:

 Latest for support of normal or TLM bitstream:
  http://btcfpga.com/files/firmware/modminer092612-TLM.bin

 Latest with only normal bitstream support (Temps/HW Fix):
  http://btcfpga.com/files/firmware/modminer091012.bin

The code is currently tested on the modminer091012.bin firmware.
This comment will be updated when others have been tested.

-

On many Linux distributions there is an app called modem-manager that may cause
problems when it is enabled, due to opening the MMQ device and writing to it.

The problem will typically present itself by the flashing led on the backplane
going out (no longer flashing) and it takes a power cycle to re-enable the MMQ
firmware - which then can lead to the problem reoccurring.

You can either disable/uninstall modem-manager if you don't need it or:
a (hack) solution to this is to blacklist the MMQ USB device in
/lib/udev/rules.d/77-mm-usb-device-blacklist.rules

Adding 2 lines like this (just above APC) should help.
# MMQ
ATTRS{idVendor}=="1fc9", ATTRS{idProduct}=="0003", ENV{ID_MM_DEVICE_IGNORE}="1"

The change will be lost and need to be re-done, next time you update the
modem-manager software.


BitForce (BFL)
--------------

--bfl-range         Use nonce range on BitForce devices if supported

This option is only for BitForce devices. Earlier devices such as the single
did not have any way of doing small amounts of work which meant that a lot of
work could be lost across block changes. Some of the Mini Rigs have support
for doing this, so less work is lost across a longpoll. However, it comes at
a cost of 1% in overall hashrate so this feature is disabled by default. It
is only recommended you enable this if you are mining with a Mini Rig on
P2Pool.

BFGMiner also bundles a bitforce-firmware-flash utility on Linux. Using this,
you can change the bitstream firmware on BitForce Singles. It is untested with
other devices. Use at your own risk! Windows users may use Butterfly Labs
EasyMiner to change firmware.

To compile:
 make bitforce-firmware-flash
To flash your BFL, specify the BFL port and the flash file e.g.:
 sudo ./bitforce-firmware-flash /dev/ttyUSB0 alphaminer_832.bfl
It takes a bit under 3 minutes to flash a BFL and shows a progress % counter
Once it completes, you may also need to wait about 15 seconds, then power the
BFL off and on again.

If you get an error at the end of the BFL flash process stating:
 "Error reading response from ZBX"
it may have worked successfully anyway.
Test mining on it to be sure if it worked or not.

You need to give BFGMiner about 10 minutes mining with the BFL to be sure of
the Mh/s value reported with the changed firmware - and the MH/s reported will
be less than the firmware speed since you lose work on every block change.


Icarus (ICA)
------------

There are two hidden options in BFGMiner when Icarus support is compiled in:

--icarus-options <arg> Set specific FPGA board configurations - one set of values for all or comma separated
           baud:work_division:fpga_count:quirks

           baud           The Serial/USB baud rate - 115200 or 57600 only - default 115200
           work_division  The fraction of work divided up for each FPGA chip - 1, 2, 4 or 8
                          e.g. 2 means each FPGA does half the nonce range - default 2
           fpga_count     The actual number of FPGA working - this would normally be the same
                          as work_division - range is from 1 up to 'work_division'
                          It defaults to the value of work_division - or 2 if you don't specify
                          work_division
           quirks         List of quirks to enable and disable (after a minus sign):
                            r  Reopen device regularly to workaround buggy Icarus USB chipset
                               (enabled by default)

If you define fewer comma separated values than Icarus devices, the last values
will be used for all extra devices.

An example would be: --icarus-options 57600:2:1:-r
This would mean: use 57600 baud, the FPGA board divides the work in half however
only 1 FPGA actually runs on the board, and don't reopen the device (e.g. like
an early CM1 Icarus copy bitstream).

--icarus-timing <arg> Set how the Icarus timing is calculated - one setting/value for all or comma separated
           default[=N]   Use the default Icarus hash time (2.6316ns)
           short         Calculate the hash time and stop adjusting it at ~315 difficulty 1 shares (~1hr)
           long          Re-calculate the hash time continuously
           value[=N]     Specify the hash time in nanoseconds (e.g. 2.6316) and abort time (e.g. 2.6316=80)

If you define fewer comma separated values than Icarus devices, the last values
will be used for all extra devices.

Icarus timing is required for devices that do not exactly match a default
Icarus Rev3 in processing speed.
If you have an Icarus Rev3 you should not normally need to use --icarus-timing
since the default values will maximise the Mh/s and display it correctly.

Icarus timing is used to determine the number of hashes that have been checked
when it aborts a nonce range (including on a longpoll).
It is also used to determine the elapsed time when it should abort a nonce
range to avoid letting the Icarus go idle, but also to safely maximise that
time.

'short' or 'long' mode should only be used on a computer that has enough CPU
available to run BFGMiner without any CPU delays (an active desktop or swapping
computer would not be stable enough).
Any CPU delays while calculating the hash time will affect the result
'short' mode only requires the computer to be stable until it has completed
~315 difficulty 1 shares, 'long' mode requires it to always be stable to ensure
accuracy, however, over time it continually corrects itself.

When in 'short' or 'long' mode, it will report the hash time value each time it
is re-calculated.
In 'short' or 'long' mode, the scan abort time starts at 5 seconds and uses the
default 2.6316ns scan hash time, for the first 5 nonces or one minute
(whichever is longer).

In 'default' or 'value' mode the 'constants' are calculated once at the start,
based on the default value or the value specified.
The optional additional =N specifies to set the default abort at N 1/10ths of a
second, not the calculated value, which is 112 for 2.6316ns

To determine the hash time value for a non Icarus Rev3 device or an Icarus Rev3
with a different bitstream to the default one, use 'long' mode and give it at
least a few hundred shares, or use 'short' mode and take note of the final hash
time value (Hs) calculated.
You can also use the RPC API 'stats' command to see the current hash time (Hs)
at any time.

The Icarus code currently only works with an FPGA device that supports the same
commands as Icarus Rev3 requires and also is less than ~840Mh/s and greater
than 2Mh/s.
If an FPGA device does hash faster than ~840Mh/s it should work correctly if
you supply the correct hash time nanoseconds value.

The timing code itself will affect the Icarus performance since it increases
the delay after work is completed or aborted until it starts again.
The increase is, however, extremely small and the actual increase is reported
with the RPC API 'stats' command (a very slow CPU will make it more noticeable).
Using the 'short' mode will remove this delay after 'short' mode completes.
The delay doesn't affect the calculation of the correct hash time.


X6500

Since X6500 FPGAs do not use serial ports for communication, the --scan-serial
option instead works with product serial numbers. By default, any devices with
the X6500 USB product id will be used, but some X6500s may have shipped without
this product id being configured. If you have any of these, you will need to
specify their serial numbers explicitly, and also add -S x6500:auto if you
still want to use the autodetection for other properly-configured FPGAs.
The serial number of X6500s is usually found on a label applied to the ATX
power connector slot. If yours is missing, devices seen by the system can be
displayed by starting bfgminer in debug mode. To get a simple list of devices,
with the debug output shown, you can use: bfgminer -D -d? -T

ZTEX FPGA Boards
---------------- 
http://www.ztex.de sells two boards suitable for mining: the 1.15x with 1 FPGA
and the 1.15y with 4 FPGAs. ZTEX distributes their own mining software and
drivers.  BFGMiner has full support for these boards.  To get started, you'll
need to install the Java JDK version 6 or later.

--- Windows ---
Upon first powering up and connecting the board via USB, windows will attempt
and fail to find the appropriate drivers.  To load the initial firmware on the
board, you'll need the EZ-USB FX2 SDK from here:
    http://www.ztex.de/downloads/#firmware_kit
Extract the firmware kit and use the driver within libusb-win32/ztex.inf.
Windows should now recognize the board and you're ready to program it.  Grab
the latest miner jar from http://www.ztex.de/btcminer/#download and program the
appropriate dummy firmware for your board.  The command should look something
like (for a single FPGA board):

java -cp ZtexBTCMiner-120417.jar BTCMiner -m p -f ztex_ufm1_15d.ihx -s 01-02-01

At this point, you're ready to mine with ZTEX's miner.  However, if you'd like
to use BFGMiner, you'll have to swap the USB drivers.  The BFGMiner compatible
WinUSB drivers for the board can be generated with this tool:
    http://sourceforge.net/projects/libwdi/files/zadig/
Basic usage instructions for Zadig can be found here:
    https://github.com/pbatard/libwdi/wiki/Zadig
Once Zadig generates and installs a WinUSB driver, ensure everything is working
by running:

bfgminer -D -d? -T

You should see something like this in the output:
[2013-01-22 20:19:11] Found 1 ztex board
[2013-01-22 20:19:11] ZTX 0: Found Ztex (ZTEX 0001-02-01-1)

Now you're ready to mine.  It's usually useful to mine with the -D -T options
and watch for ZTEX related messages.