Control UART from QEMU

[caipiblack]

Dear sir,

When I try to get the output of the UART's of the ESP32, i can only get the results from the first one.

Example using TCP Server:

qemu/xtensa-softmmu/qemu-system-xtensa -nographic -s -S -machine esp32 -drive file=final.bin,if=mtd,format=raw -nic user,model=open_eth -serial tcp::8880,server,nowait -serial tcp::8881,server,nowait

Example using files:

qemu/xtensa-softmmu/qemu-system-xtensa -nographic -s -S -machine esp32 -drive file=final.bin,if=mtd,format=raw -nic user,model=open_eth -serial file:/tmp/uart0.txt -serial file:/tmp/uart1.txt

Did we have to implement somthing in esp32.c ?

[caipiblack]

I found that i can receive the data from transmit by the ESP32 from UART 1 & 2 by doing these modifications:

in the function “esp32_soc_init()”(esp32.c), add these lines:

object_property_add_alias(obj, "serial1", OBJECT(&s->uart[1]), "chardev", &error_abort);
object_property_add_alias(obj, "serial2", OBJECT(&s->uart[2]), "chardev", &error_abort);

in the function “esp32_machine_inst_init()”(esp32.c), add these lines:

qdev_prop_set_chr(DEVICE(s), "serial1", serial_hd(1));
qdev_prop_set_chr(DEVICE(s), "serial2", serial_hd(2));

Then I can receive the data transmit by the ESP32 on UART's.

Using TCP servers:
-serial tcp::8880,server,nowait -serial tcp::8881,server,nowait -serial tcp::8882,server,nowait

Using files:
-serial file:/tmp/uart0.txt -serial file:/tmp/uart1.txt -serial file:/tmp/uart2.txt

Using /dev/tty..:
-serial /dev/ttyS4 -serial /dev/ttyS5 -serial /dev/ttyS6

I arrive to get the data transmit by the emulated ESP32, but I don't arrive to transmit data to the ESP32.

Did you know if we have something else to change somewhere ?

Thanks

[caipiblack]

I got a response about it on the esp32 forum:

https://www.esp32.com/viewtopic.php?f=2&t=18358

It seems that we have to implement the interruption UART_RXFIFO_TOUT, but i don't know how to implement this on QEMU, did you have any ideas?

[igrr]

@caipiblack RXFIFO_TOUT interrupt is implemented in the latest esp-develop branch. I have also included your suggestion for exposing UART1 and UART2, thanks for that!

[manimathma]

@caipiblack , couldn't get this to work. Do we need to call some init function from main?