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Topics - tnt

1
Bus Pirate Development / Howto rebuild the firmware
Hi,

I was wondering if there was something special needed to rebuild the firmware ?

I downloaded MPLAB and the C compiler evaluation, installed them. Then cloned the SVN and loaded the project file in source/ and build that.
Then I tried flashing the output/busPirate.hex resulting of this but the loaded doesn't even want to load the .hex file ...

    Sylvain
2
OpenOCD JTAG / JTAG quite slow and ideas to make it go faster
Hi,

Yesterday I had to dump the NOR from a target with JTAG. It took about 8 hours to dump 64 Mo of flash. That's pretty long !

When looking at the jtag bus, I notices that it is currently the limiting factor. (the with 'fast' uart mode, the uart keeps up but is slowed down by the bit-banging).

The JTAG bus is aroung 100-125 kHz  right now (with a very un-even duty cycle). I think that by using an optimized loop, we could bring that to 500 - 600 kHz. Which should provide a pretty nice speed up.

I haven't programmed PIC in a long time ... (back when the 16f84 was a new product), but I tried estimating what could be done by a quick look at the datasheet. Below is what I came up with (probably buggy but that's just to estimate the cycle count) :

Basically there would be several 'layers' of loop to avoid doing the uart test or handling #bits != 16 ... and you'd have one very fast function doing just the bit bang for a certain number of 16 bits words and for the 'end' and when uart flushes are needed, we'd just have an outer loop in C.


[tt:]params:
        W0      inBuffer
        W1      outBuffer
        W2      bits

                # Main full 16 bits loop
                # ----------------------

                SL      W2, #4, W3              # W3 = W2 >> 4;
_loop_f16:                                      # do {

                #  Fetch & organize 2x16 bits
                MOV     [W0++], W5              #   W5 = *((uint16_t*)W0++);
                MOV     [W0++], W6              #   W6 = *((uint16_t*)W0++);

                        # W5 has one byte TMS and one byte TDO
                        # W6 has one btes TMS and one byte TDO
                        #  -> We must reorgonize that !
                SWAP    W6                      #   W6 = swap_bytes(W6);
                XOR     W5, W6, W7              #   W7 = W5 ^ W6;
                AND     #0xff, W7               #   W7 &= 0xff;
                XOR     W5, W7, W5              #   W5 = W5 ^ W7;
                XOR     W6, W7, W6              #   W6 = W6 ^ W7;
                SWAP    W6                      #   W6 = swap_bytes(W6);

                #  Clear destination register
                CLR     W7

                #  Inner loop
                MOV     #15, W4
_loop_f16_inner:

                #   Clear TCK
                BCLR    IOPOR, OOCD_TCK

                #   Set TDO & TMS
                MOV     IOPOR, W8
                BTST.Z  W5, W4
                BSW.Z   W8, OOCD_TDO
                BTST.Z  W6, W4
                BSW.Z   W8, OOCD_TMS
                MOV     W8, IOPOR1

                #   Set TCK
                BSET    IOPOR, OOCD_TCK

                #   Read TDI
                BTST    IOPOR, OOCD_TDI
                BSW.Z   W7, W4

                #   Loop condition
                DEC     W4
                BRA     NZ, _loop_f16_inner

                #  Store result
                MOV     W7, [W1++]

                #  Loop condition
                DEC     W3, W3
                BRA     NC, _loop_f16           # } while (W2--);



                # FIXME: Do the rest 0..15 bits[/tt:]
3
OpenOCD JTAG / [solved: use v5.1] OpenOCD Broken with FW V5.0
Hi,

I just tried the OpenOCD with the v5 firmware ( BPv3-Firmware-v5.0.hex ) and it doesn't work (not even the IDCODE)
Looking at it with a logic analyzer shows the the commands sent to the JTAG bus are correct, the TDO signal is correct on the bus but does _not_ match the bits received by openocd.

With the exact same setup and just reflashing to BPv3-Firmware-v4.2.OpenOCD.hex and things work fine.

Cheers,

   Sylvain

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