TPM 1.2 at U-BOOT

Autonomous Machines Jetson & Embedded Systems Jetson TK1
1

Hello Dear,

I attached TPM 1.2 module via I2C to GEN2_I2C, on the J3A1 expansion socket.
TPM chip is Infineon’s SLB9645.
To enable TPM, required configurations are added as follow:

#define CONFIG_TPM
#define CONFIG_TPM_TIS_I2C
#define CONFIG_TPM_TIS_I2C_BUS_NUMBER 2
#define CONFIG_TPM_TIS_I2C_SLAVE_ADDRESS 0x20
#define CONFIG_CMD_TPM
#define CONFIG_TPM_TARGET_TK1

After flash fusing, I probed I2C firstly.

Tegra124 (Jetson TK1) # i2c dev 2
Setting bus to 2
Tegra124 (Jetson TK1) # i2c probe
Valid chip addresses: 20

probing done.

But TPM commands failed during tpm_transmit () of drivers/tpm/tpm.c:396.
By investigation, it seems like request_locality() failed.

Tegra124 (Jetson TK1) # tpm init
Tegra124 (Jetson TK1) # tpm startup TPM_ST_CLEAR
ERROR: tpm_transmit: tpm_send: error 4294967280

at /home/ubuntu/build_src/u-boot/drivers/tpm/tpm.c:396/tpm_transmit()

How can I resolve this issue in this case?

Thanks,

2

Hi mipsan,

What are the connections of other signals of TPM, such as RESET#, DAVINT# and PP pin?

3

Hi Trumany,

RESET is not connected.
3.3V, GND, SCL and SDA 4 pins are connected.

During debugging, if fails request_locality() which is done before TX/RX job.

update!
PP is connected to VDD, 3.3V.

update again!
PP pin is connected to a jumper.
Then I tested it both open and close.
Same result I have.

4

Hi Trumany,

2014.10 U-Boot version is used for my Jetson-TK1 currently.
Does it matter with TPM?

5

Hi mipsan

  1. Seems the tpm_send will call the tpm_tis_i2c_send(), could you check which code failed?
  2. Does the i2c tools can recognize it by i2c tools.
6

Hi Shane,

  1. YES True.
static ssize_t tpm_transmit(const unsigned char *buf, size_t bufsiz)
{
....
        rc = chip->vendor.send(chip, (u8 *)buf, count);
        if (rc < 0) {
                error("tpm_transmit: tpm_send: error %zd\n", rc);
                goto out;
        }

The send() function calls tpm_tis_i2c_send(), because of this,

static struct tpm_vendor_specific tpm_tis_i2c = {
        .status = tpm_tis_i2c_status,
        .recv = tpm_tis_i2c_recv,
        .send = tpm_tis_i2c_send,
        .cancel = tpm_tis_i2c_ready,
        .req_complete_mask = TPM_STS_DATA_AVAIL | TPM_STS_VALID,
        .req_complete_val = TPM_STS_DATA_AVAIL | TPM_STS_VALID,
        .req_canceled = TPM_STS_COMMAND_READY,
};

I’ve got a screenshot. However, no idea how to upload it here.

  1. U-BOOT has simple I2C command, not i2c-tools as Linux.
    If I down I2C speed around 30000bps, I2C command can read VID from TPM chip.
7

Replied in [url]https://devtalk.nvidia.com/default/topic/1015194/tpm-1-2-at-u-boot-tk1/[/url]