[BeaglePlay] Wrong hostname on beagleplay

[microhobby]

This beagleplay-recovery-mode does not sounds correct. We need to investigate and get the actual serial number instead, as all the other models.

[charles2910]

I'll leave things here as an investigation log :-)

Things related to hostname happens in meta-toradex-bsp-common/recipes-core/set-hostname. There we have the sethostname file with the following contents:

#!/bin/sh
if [ ! -f /proc/device-tree/serial-number ]; then
    serial="recovery-mode"
else
    serial=$(tr -d '\0' </proc/device-tree/serial-number)

    #if serial number is empty we append no-serial-number string
    if [ -z "$serial" -a "$serial" != " "  ]; then
        serial="no-serial-number"
    fi
fi

hostname=@@MACHINE@@"-"${serial}

if [ -f /usr/bin/hostnamectl ]; then
    /usr/bin/hostnamectl set-hostname ${hostname}
else
    hostname ${hostname}
fi

So, we need to get the correct serial number for it wherever beagleplay make it available for us

[charles2910]

There is a project whose goal is to get the serial of various boards. It's called boardid. It supports reading beagleplay serial and also gives us a hint on how to get it:

static void extract_beagleplay_serial(const unsigned char *data, char *buffer)
{
    // BeaglePlay EEPROM Layout
    // See https://git.beagleboard.org/beagleplay/beagleplay/-/blob/main/EEPROM.md
    //
    // Multibyte integers are little endian
    //
    // Offset Size Contents
    // 0      4    Header (AA,55,33,EE)
    // 4      1    Type (1)
    // 5      2    Payload size (0x37)
    // 7      1    BRD_INFO (0x10)
    // 8      2    0x2e
    // 10     16   Board_Name (BEAGLEPLAY-A0-\0\0)
    // 26     2    Design_Rev (0x02)
    // 28     4    PROC_Nbr
    // ...
    // 40     2    VendorID (ASCII "64")
    // 42     2    Build_Week (ASCII)
    // 44     2    Build_Year (ASCII)
    // 46     6    Board_ID (ASCII)
    // 52     4    Serial_Nbr (ASCII "SSSS")
    //
    // The serial number is set to all S's, so use the Board_ID.
    // The Board_ID is the last 6 digits on the QRCode sticker.
    // E.g., BPVA2022510000123 where 2022 is the Build_Year and 51 is the
    // Build_Week.

    const int digits = 6;
    memcpy(buffer, &data[46], digits);
    buffer[digits] = 0;
}

// Read the serial number from the Beaglebone's EEPROM
bool beagleboneblack_id(const struct boardid_options *options, char *buffer)
{
    // Try both the Linux 3.8 and 4.1 EEPROM locations
    FILE *fp = fopen_helper("/sys/bus/i2c/devices/0-0050/eeprom", "r");
    if (!fp)
        fp = fopen_helper("/sys/bus/i2c/devices/0-0050/at24-0/nvmem", "r");

    if (!fp)
        return 0;

    unsigned char data[56];
    if (fread(data, 1, sizeof(data), fp) != sizeof(data)) {
        fclose(fp);
        return false;
    }

    fclose(fp);

    // Verify that the EEPROM was programmed
    if (data[0] != 0xaa ||
            data[1] != 0x55 ||
            data[2] != 0x33 ||
            data[3] != 0xee)
        return false;

    // BeaglePlay has a non-ASCII 1 at offset 4 and follow it with the data
    // size. Beagleboards should have ASCII letters there.
    if (data[4] == 0x01 && data[5] == 0x37 && data[6] == 0)
        extract_beagleplay_serial(data, buffer);
    else
        extract_bbb_serial(data, buffer);

    return true;
}

We can't even get from uboot env, it's all set to SSSS

[charles2910]

This command does the trick, but it's a pretty poor solution in my opinion:

tail -c +47 /sys/bus/i2c/devices/0-0050/eeprom | head -c 6

@microhobby do you have any recommendations on how to proceed at this point?

[microhobby]

@charles2910 did you think that there is some issue on u-boot side? I mean, u-boot should fill the env with the serial, or no?