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More detailed tests with the JTAG-lock-pick Tiny 2

Message ID 20210803025131.245dfba6@primarylaptop.localdomain
State New
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Series More detailed tests with the JTAG-lock-pick Tiny 2 | expand

Commit Message

Denis 'GNUtoo' Carikli Aug. 3, 2021, 12:51 a.m. UTC 
Hi,

I've tried to make the Distortec JTAG-lock-pick Tiny 2[1][2] work with
flashrom and for some reason it always read the same thing.

Back in April there was also a thread about it[0], but not much details
were shared about the setup, so since I tried things, I also took the
occasion to try to share them here.

The JTAG-lock-pick Tiny 2 connector is similar to the one of the Olimex
ARM-USB-TINY that is described in the wiki[3].

Even if the connector is the same, there are some differences between
both hardware designs:
- On the JTAG-lock-pick Tiny 2, VREF and VTARGET are connected
  together according to its schematics that are in its manual[4].
- Users are supposed to connect a reference voltage to any of these two
  pins (VREF and VTARGET).
- The pins 17 and 19 are not connected (NC) at all.
- The JTAG-lock-pick Tiny 2 uses an FTD232HL chip (among with other
  chips like a CPLD and some chips to isolate the target device from
  it).

I've made the following patch to try to use it:


I've connected it in the same way described in the wiki for the Olimex
ARM-USB-TINY[3], with wires that are about 10 centimeters, and I've
provided 3.3v on VREF/VTARGET. When doing that flashrom always reads
0xff:

> ./flashrom -p ft2232_spi:type=JTAG-lock-pick,divisor=131072 --verbose
> [...]
> Probing for Sanyo unknown Sanyo SPI chip, 0 kB: RDID byte 0 
>         parity violation. compare_id: id1 0xff, id2 0xffff
> Probing for Winbond unknown Winbond (ex Nexcom) SPI chip, 0 kB: RDID
>         byte 0 parity violation. compare_id: id1 0xff, id2 0xffff
> Probing for Generic Variable Size SPI chip, 64 kB: Probing for Generic
>         unknown SPI chip (RDID), 0 kB: RDID byte 0 parity violation.
>         compare_id: id1 0xff, id2 0xffff
> Probing for Generic unknown SPI chip (REMS), 0 kB: compare_id: 
>         id1 0xff, id2 0xff
> No EEPROM/flash device found.
> Note: flashrom can never write if the flash chip isn't found
> automatically.
> Releasing I/Os

If instead I remove the power source, flashrom always reads zeros
(0x00) instead of ones (0xff).

If I go to about 1volt, flashrom still reads 0xff.

That device is also supported by openocd and there I managed to use it
to reprogram a microcontroller through SWD.

With the same connection, on an openmoko debug board (connecting the
3.3v source to VTARGET), I get the following result:
> ./flashrom -p ft2232_spi:type=openmoko,divisor=131072 --verbose
> Probing for Winbond unknown Winbond (ex Nexcom) SPI chip, 0 kB:
>         compare_id: id1 0xef, id2 0x4017
> Probing for Generic Variable Size SPI chip, 64 kB: 
> Probing for Generic unknown SPI chip (RDID), 0 kB: 
>         compare_id: id1 0xef, id2 0x4017 
> Probing for Generic unknown SPI chip (REMS), 0 kB: 
>         compare_id: id1 0xef, id2 0x16
> Found Winbond flash chip "W25Q64.V" (8192 kB, SPI).
> This chip may contain one-time programmable memory. flashrom cannot
> read and may never be able to write it, hence it may not be able to
> completely clone the contents of this chip (see man page for
> details). 
> No operations were specified. 
> Releasing I/Os

So something is probably wrong somewhere.

Note that in the distribution I use (Parabola i686), the FT232H support
seems to be supported in libftdi as when running make in the flashrom
source directory I have:
> Checking for FTDI support... found.
> Checking for FT232H support in libftdi... found.

I wonder if there is some easy way to make the JTAG-lock-pick Tiny 2
work, as it is quite small and it also does JTAG and SWD, and it'd
probably be more reliable than the Arduino that I use at 3.3v (which
also needs a 3.3v power source to run at 3.3v).

References:
-----------
[0]https://www.mail-archive.com/flashrom@flashrom.org/msg14801.html
[1]https://distortec.com/jtag-lock-pick-tiny-2/
[2]https://shop.sysmocom.de/products/jtag-lock-pick-tiny-2
[3]https://www.flashrom.org/FT2232SPI_Programmer#Olimex_ARM-USB-TINY.2F-H_and_ARM-USB-OCD.2F-H
[4]https://distortec.com/download/70/
[5]https://ftdichip.com/products/ft232hl/
[6]https://ftdichip.com/wp-content/uploads/2020/07/DS_FT232H.pdf
[7]https://www.mail-archive.com/flashrom@flashrom.org/msg14801.html

Denis.
diff mbox series

Patch

diff --git a/ft2232_spi.c b/ft2232_spi.c
index e32d7f81..d986e0a2 100644
--- a/ft2232_spi.c
+++ b/ft2232_spi.c
@@ -38,6 +38,7 @@ 
 #define FTDI_FT2232H_PID       0x6010
 #define FTDI_FT4232H_PID       0x6011
 #define FTDI_FT232H_PID                0x6014
+#define DISTORTEC_JTAG_LOCK_PICK_TINY_2_PID    0x8220
 #define TIAO_TUMPA_PID         0x8a98
 #define TIAO_TUMPA_LITE_PID    0x8a99
 #define AMONTEC_JTAGKEY_PID    0xCFF8
@@ -66,6 +67,7 @@  static const struct dev_entry devs_ft2232spi[] = {
        {FTDI_VID, TIAO_TUMPA_PID, OK, "TIAO", "USB Multi-Protocol Adapter"},
        {FTDI_VID, TIAO_TUMPA_LITE_PID, OK, "TIAO", "USB Multi-Protocol Adapter Lite"},
        {FTDI_VID, AMONTEC_JTAGKEY_PID, OK, "Amontec", "JTAGkey"},
+       {FTDI_VID, DISTORTEC_JTAG_LOCK_PICK_TINY_2_PID, OK, "Distortec", "JTAG-lock-pick"},
        {GOEPEL_VID, GOEPEL_PICOTAP_PID, OK, "GOEPEL", "PicoTAP"},
        {GOOGLE_VID, GOOGLE_SERVO_PID, OK, "Google", "Servo"},
        {GOOGLE_VID, GOOGLE_SERVO_V2_PID0, OK, "Google", "Servo V2 Legacy"},
@@ -350,6 +352,13 @@  static int ft2232_spi_init(void)
                        ft2232_vid = GOEPEL_VID;
                        ft2232_type = GOEPEL_PICOTAP_PID;
                        channel_count = 2;
+               } else if (!strcasecmp(arg, "JTAG-lock-pick")) {
+                        ft2232_type = DISTORTEC_JTAG_LOCK_PICK_TINY_2_PID;
+                       /* It contains an FTD232HL chip. Its datasheet has
+                        * "FT232H SINGLE CHANNEL HI-SPEED USB TO MULTIPURPOSE
+                        * UART/FIFO IC"
+                        */
+                       channel_count = 1;
                } else if (!strcasecmp(arg, "tumpa")) {
                        /* Interface A is SPI1, B is SPI2. */
                        ft2232_type = TIAO_TUMPA_PID;