Thanks for quick replay - all makes sense... But I don't see u-boot feeding it... It always reboots after 2-3min, when I wait in the u-boot terminal. This sadly does not give me enough time for serial upload.
best,
Got it...
I do not know much about how u-boot works in detail, but: If I don't set the boardmodel env var, the rtk network on command lists me all available boards and forces me to set the env var before it tries to init the network...
Are you sure it's gpio 21? (and not 0?)
gpioPin = 0x15;
if (2 < port_type - 0x14U) {
gpioPin = 0;
}
I haven't traced back to try to work out where port_type is set, and what the value would be (i.e. > 0x16 then gpio=0)
Strange. Never thought about such a dependency. All my devices simply bring up the network in the right way. Maybe in your case it is the rtk library that does it after system boot.
Everything I see in this thread sounds a lot like the S1300WP-8GT-2S+ I've been messing with, including the timing of this watchdog reset.
If you have i2c-poe.ko loaded into ghidra, have a look at the g_poe_scl_pin and g_poe_sda_pin or the rtk_i2c_poe_init function - maybe they are different in your case and that's why the script didn't work? The imi binary, the imi_mcu_watchdog_* functions are the interesting ones.
Also I didn't check if the MMIO registers are different, since this seems to be a mango chip while mine is a longan.