[FEATURE] Look at QEMU vm states

[vintagepc]

Is your feature request related to a problem? Please describe.

QEMU supports saving and restoring states. Now that things are mostly working, perhaps we can implement that for easier testing.

• [x] parts/encoder_input.c
• [x] parts/fan.c
• [x] parts/heater.c
• [x] parts/irsensor.c
• [x] parts/mini_visuals.c
• [x] parts/st7789v.c
• [x] parts/thermistor.c
• [x] parts/tmc2209.c
• [x] stm32f407/stm32_clktree.c
• [x] stm32f407/stm32f2xx_crc.c
• [x] stm32f407/stm32f2xx_dma.c
• [x] stm32f407/stm32f2xx_flashint.c
• [x] stm32f407/stm32f2xx_gpio.c
• [x] stm32f407/stm32f2xx_i2c.c
• [x] stm32f407/stm32f2xx_pwr.c
• [x] stm32f407/stm32f2xx_rcc.c
• [x] stm32f407/stm32f2xx_rtc.c
• [x] stm32f407/stm32f2xx_tim.c
• [x] stm32f407/stm32f4xx_adc.c
• [x] stm32f407/stm32f4xx_eth.c
• [x] stm32f407/stm32f4xx_itm.c
• [x] stm32f407/stm32f4xx_iwdg.c
• [x] stm32f407/stm32f4xx_otp.c
• [x] stm32f407/stm32f4xx_spi.c
• [x] stm32f407/stm32f4xx_usb.c
• [x] stm32f407/stm32_rcc.c
• [x] stm32f407/stm32_uart.c

[vintagepc]

@wavexx you'll be happy to know this looks pretty straightforward, just need to add load/save handlers to the various components. :+1:

[vintagepc]

I have most of this implemented in "our" parts but there's something wrong with restoring the states. Need to investigate whether there is missing support somewhere else or whether it's a bug in the state saving definitions.