proxmark3/armsrc/hfsnoop.c

//-----------------------------------------------------------------------------
// piwi, 2019
//
// This code is licensed to you under the terms of the GNU GPL, version 2 or,
// at your option, any later version. See the LICENSE.txt file for the text of
// the license.
//-----------------------------------------------------------------------------
// Routines to get sample data from FPGA.
//-----------------------------------------------------------------------------
#include "hfsnoop.h"
#include "proxmark3_arm.h"
#include "BigBuf.h"
#include "fpgaloader.h"
#include "ticks.h"
#include "dbprint.h"
#include "util.h"
#include "fpga.h"
#include "appmain.h"
#include "cmd.h"

static void RAMFUNC optimizedSniff(void) {
    int n = BigBuf_max_traceLen() / sizeof(uint16_t); // take all memory

    uint16_t *dest = (uint16_t *)BigBuf_get_addr();
    uint16_t *destend = dest + n - 1;

    // Reading data loop
    while (dest <= destend) {
        if (AT91C_BASE_SSC->SSC_SR & AT91C_SSC_RXRDY) {
            *dest = (uint16_t)(AT91C_BASE_SSC->SSC_RHR);
            dest++;
        }
    }
    //setting tracelen - important!  it was set by buffer overflow before
    set_tracelen(BigBuf_max_traceLen());
}

void HfSniff(int samplesToSkip, int triggersToSkip) {
    BigBuf_free();
    BigBuf_Clear();

    Dbprintf("Skipping first %d sample pairs, Skipping %d triggers.\n", samplesToSkip, triggersToSkip);
    int trigger_cnt = 0;

    LED_D_ON();

    FpgaDownloadAndGo(FPGA_BITSTREAM_HF);

    SetAdcMuxFor(GPIO_MUXSEL_HIPKD);

    // Set up the synchronous serial port
    FpgaSetupSsc();

    // Setting Frame Mode For better performance on high speed data transfer.
    AT91C_BASE_SSC->SSC_RFMR = SSC_FRAME_MODE_BITS_IN_WORD(16);

    FpgaWriteConfWord(FPGA_MAJOR_MODE_HF_SNOOP);
    SpinDelay(100);

    uint16_t r = 0;
    while (!BUTTON_PRESS() && !data_available()) {
        WDT_HIT();

        if (AT91C_BASE_SSC->SSC_SR & (AT91C_SSC_RXRDY)) {
            r = (uint16_t)AT91C_BASE_SSC->SSC_RHR;
            r = MAX(r & 0xff, r >> 8);
            if (r >= 180) {  // 0xB4 ??
                if (++trigger_cnt > triggersToSkip)
                    break;
            }
        }
    }

    if (!BUTTON_PRESS()) {
        int waitcount = samplesToSkip; // lets wait 40000 ticks of pck0
        while (waitcount != 0) {

            if (AT91C_BASE_SSC->SSC_SR & (AT91C_SSC_RXRDY))
                waitcount--;
        }
        optimizedSniff();
        Dbprintf("Trigger kicked! Value: %d, Dumping Samples Hispeed now.", r);
    }

    //Resetting Frame mode (First set in fpgaloader.c)
    AT91C_BASE_SSC->SSC_RFMR = SSC_FRAME_MODE_BITS_IN_WORD(8) | AT91C_SSC_MSBF | SSC_FRAME_MODE_WORDS_PER_TRANSFER(0);

    DbpString("HF Sniffing end");
    FpgaWriteConfWord(FPGA_MAJOR_MODE_OFF);
    LED_D_OFF();
}

void HfPlotDownload(void) {
    uint8_t *buf = ToSend;
    uint8_t *this_buf = buf;

    FpgaDownloadAndGo(FPGA_BITSTREAM_HF);

    FpgaSetupSsc();

    AT91C_BASE_PDC_SSC->PDC_PTCR = AT91C_PDC_RXTDIS;   // Disable DMA Transfer
    AT91C_BASE_PDC_SSC->PDC_RPR = (uint32_t) this_buf; // start transfer to this memory address
    AT91C_BASE_PDC_SSC->PDC_RCR = PM3_CMD_DATA_SIZE;   // transfer this many samples
    buf[0] = (uint8_t)AT91C_BASE_SSC->SSC_RHR;         // clear receive register
    AT91C_BASE_PDC_SSC->PDC_PTCR = AT91C_PDC_RXTEN;    // Start DMA transfer

    FpgaWriteConfWord(FPGA_MAJOR_MODE_HF_GET_TRACE);   // let FPGA transfer its internal Block-RAM

    LED_B_ON();
    for (size_t i = 0; i < FPGA_TRACE_SIZE; i += PM3_CMD_DATA_SIZE) {
        // prepare next DMA transfer:
        uint8_t *next_buf = buf + ((i + PM3_CMD_DATA_SIZE) % (2 * PM3_CMD_DATA_SIZE));

        AT91C_BASE_PDC_SSC->PDC_RNPR = (uint32_t)next_buf;
        AT91C_BASE_PDC_SSC->PDC_RNCR = PM3_CMD_DATA_SIZE;

        size_t len = MIN(FPGA_TRACE_SIZE - i, PM3_CMD_DATA_SIZE);

        while (!(AT91C_BASE_SSC->SSC_SR & (AT91C_SSC_ENDRX))) {}; // wait for DMA transfer to complete

        reply_old(CMD_FPGAMEM_DOWNLOADED, i, len, FPGA_TRACE_SIZE, this_buf, len);
        this_buf = next_buf;
    }

    FpgaWriteConfWord(FPGA_MAJOR_MODE_OFF);

    // Trigger a finish downloading signal with an ACK frame
    reply_mix(CMD_ACK, 1, 0, FPGA_TRACE_SIZE, 0, 0);
    LED_B_OFF();
}