Lenovo S2 support

[Johnmcenroyy]

Hello
I have bought Lenovo S2 for experiments with Pinetime's firmwares.

Lenovo S2
soc NRF52832
nor flash XT25F64B (8mb)
display 240x240 (ST7789 ?)
touchscreen Hynitron CST816S
accelerometer ST LIS2DW12 (3-axis, temperature)
heart rate sensor PixArt PAH8011ET (2 green + 1 ir, dsp)

I have connected with SWD to Openocd-spi with Raspberry Pi.
Unlocked flash with scripts from:
https://github.com/lupyuen/pinetime-updater
Flashed with these scripts then Infinitime bootloader and firmware, but black screen on boot.

According to InfiniTimeOrg/pinetime-mcuboot-bootloader#10
The P8 watch for example differs from the Pinetime in a few minor points:
1. Different pins for the button (Now configurable via libs/pinetime_boot/syscfg.yml)
2. Some variants have no external low frequency crystal
3. Different SPI flash chips are used

So I have build fork https://github.com/StarGate01/pinetime-mcuboot-bootloader/tree/p8b
which solves 2 and 3, flashed it but also black screen.

How I understand I can connect UART (with compiled UART bootloader) to see logs what happens,
but need to search on what pin UART is, for example Pinetime pin TX is number 11.

I have these settings for bootloader:
UART_0: 1
UART_0_PIN_TX: 11 # must find correct pin for Lenovo S2 UART
CONSOLE_UART: 1
Is it sufficient for get UART logs or need something else, for example LOG_CLI and LOG_LEVEL settings ?

Any ideas ?
Thanks.

[Johnmcenroyy]

It seems that a better way to use Real Time Transfer (RTT) through SWD interface.

[Avamander]

Yes, Semihosting or RTT.

[Johnmcenroyy]

Hi Avamander.
Does Semihosting will give log of MCUBoot ?
Thanks.

[Johnmcenroyy]

Ok, found: https://lupyuen.github.io/pinetime-rust-mynewt/articles/mcuboot#enable-sysinit-hook
Display debugging messages from MCUBoot via the Arm Semihosting Console (in OpenOCD)

[Johnmcenroyy]

What is the best way to find unknown pinout of watch to make it support in Infinitime ?
Multimeter, i2c scanner etc. ?

Thanks

[SteveAmor]

atc1441 is the expert at reverse engineering these types of watches. A couple of things he has done are a) strip all components off the PCB to check nrf connections and b) intercept companion Android app to get the source of firmware updates, download the firmware update and reverse engineer the code using Ghidra IIRC.

[Johnmcenroyy]

Thanks for info. I am read some info at atc1441 github. For b) Unfortunately, I have erased all firmware in flash by deleting APPROTECT security and a) I have just remove all and now check connections to nrf52832. Will see :)

[ildar]

I suggest skipping the bootloader for this stage and work with the InfiniTime fw only (i.e. pinetime-app-image-*.bin). And to get help on hacking a new device ask at https://matrix.to/#/!xchlMpnFYulPioyGdI:gitter.im

[Johnmcenroyy]

Thank you very much. I just found also that is better for debug without bootloader,
but for now can't reduce size of firmware for compile with debug enabled.