Miyoo Mini

Links

Emulators, Ports and Applications

• Ports by steward-fu
• Ports and builds by Eggs

System

• Firmware:
  • 20220419 for Mini v1 and v2
  • Community Firmware for Mini v3
  • 20230326 for Mini+
  • Unbrick Guide
• Toolchain:
  • MiyooMini
  • Shauniman
  • OnionUI
• Frontends:
  • Koriki
  • Onion
  • MiniUI

Hardware

• Official store in Aliexpress
• UART mod:
  • steward-fu
  • eduardofilo
• Teardown
• 3D Print:
  • More accessible triggers: V1, V2
• Spare parts

Firmware's rootfs mounting

1. Download the file used to update the console firmware from official site.
2. Locate inside the ZIP the .img file. In the case of the 2022-04-19 update the file is located in The firmware0419 directory and is named myoo283_fw.img.

3. Open the file with an hex editor to read the beginning of it which contains information in text form with the blocks inside the image and where they are flashed on the NAND. In particular we are interested in the section describing the rootfs partition which contains the following information:

   # File Partition: rootfs
   mxp r.info rootfs
   sf probe 0
   sf erase ${sf_part_start} ${sf_part_size}
   fatload mmc 0 0x21000000 $(SdUpgradeImage) 0x1ae000 0x22b000
   sf write 0x21000000 ${sf_part_start} 0x1AE000
   

4. According to the U-boot fatload command documentation, the last two parameters in hexadecimal are the size and the position of the rootfs partition inside the .img file.

5. Create a directory (for example mnt) and run the following command to mount the firmware rootfs in it:

   sudo mount -o loop,sizelimit=0x1ae000,offset=0x22b000,ro,noexec miyoo283_fw.img mnt
   

Using the same method you can also mount the miservice and customer partitions:

sudo mount -o loop,sizelimit=0x32f000,offset=0x3d9000,ro,noexec miyoo283_fw.img mnt2
sudo mount -o loop,sizelimit=0x6c5000,offset=0x708000,ro,noexec miyoo283_fw.img mnt3

Cheatsheets

Interesting firmware directories/files

Directory	Content
/mnt/SDCARD	SD mounting point
/customer/main	Main frontend startup script. It is the one that invokes .tmp_update/updater in case it exists which is the starting point of UIs like Onion or MiniUI
/sys/devices/gpiochip0/gpio/gpio59/value	Flag indicating if the machine is being charged
/sys/class/pwm/pwmchip0/pwm0/duty_cycle	Screen brightness (from 0 to 100)
/sys/devices/system/cpu/cpufreq/policy0/scaling_available_governors	Available governors for processor (userspace, powersave, ondemand, performance)
/sys/devices/system/cpu/cpufreq/policy0/scaling_governor	Current governor
/sys/devices/system/cpu/cpufreq/policy0/scaling_available_frequencies	Available frequencies for processor (400000, 600000, 800000, 1000000, 1100000, 1200000)
/sys/devices/system/cpu/cpufreq/policy0/scaling_min_freq	Minimum frequency for processor
/sys/devices/system/cpu/cpufreq/policy0/scaling_max_freq	Maximum frecuency for processor
/sys/devices/system/cpu/cpufreq/policy0/scaling_cur_freq	Current frecuency
/appconfigs/system.json	System general settings (corresponds to Settings menu)

Interesting OnionUI directories/files

Directory	Content
/mnt/SDCARD/Saves/CurrentProfile/saves/playActivity.db	Play Activity database. To reset the statistics, you can simply delete the file
/mnt/SDCARD/Saves/CurrentProfile/saves/PlayActivityBackup/	Directory containing backups of the previous playActivity.db file. Apparently this directory is not purged, so you will have to do it by hand from time to time.
/mnt/SDCARD/Roms/recentlist.json	Recent list
/mnt/SDCARD/.tmp_update/romScreens/	Screenshots
/mnt/SDCARD/.tmp_update/.disableMenu	Disables the Game Switcher associated with the Menu key

GPIOs

/ # cat /sys/kernel/debug/gpio
gpiochip0: GPIOs 0-90, gpio:
 gpio-1   (                    |GPIO Key Up         ) in  hi
 gpio-5   (                    |GPIO Key Right      ) in  hi
 gpio-6   (                    |GPIO Key B          ) in  hi
 gpio-7   (                    |GPIO Key Y          ) in  hi
 gpio-8   (                    |GPIO Key A          ) in  hi
 gpio-9   (                    |GPIO Key X          ) in  hi
 gpio-10  (                    |GPIO Key START      ) in  hi
 gpio-11  (                    |GPIO Key SELECT     ) in  hi
 gpio-12  (                    |GPIO Key MENU       ) in  hi
 gpio-13  (                    |GPIO Key L          ) in  hi
 gpio-14  (                    |GPIO Key L2         ) in  hi
 gpio-47  (                    |GPIO Key R2         ) in  hi
 gpio-59  (                    |sysfs               ) in  lo
 gpio-69  (                    |GPIO Key Down       ) in  hi
 gpio-70  (                    |GPIO Key Left       ) in  hi
 gpio-72  (                    |                    ) out lo
 gpio-86  (                    |GPIO Key POWER      ) in  lo
 gpio-90  (                    |GPIO Key R          ) in  hi

Keys

Key	GPIO	SDL value	SDL descriptor
Up	1	273	SDLK_UP
Down	69	274	SDLK_DOWN
Left	70	276	SDLK_LEFT
Right	5	275	SDLK_RIGHT
Menu	12	27	SDLK_ESCAPE
A	8	32	SDLK_SPACE
B	6	306	SDLK_LCTRL
X	9	304	SDLK_LSHIFT
Y	7	308	SDLK_LALT
Select	11	305	SDLK_RCTRL
Start	10	13	SDLK_RETURN
L1	13	101	SDLK_e
L2	14	9	SDLK_TAB
R1	90	116	SDLK_t
R2	47	8	SDLK_BACKSPACE

Framebuffer

/ # fbset

mode "640x480-100"
        # D: 45.455 MHz, H: 54.633 kHz, V: 100.060 Hz
        geometry 640 480 640 1440 32
        timings 22000 64 64 32 32 64 2
        accel false
        rgba 8/16,8/8,8/0,8/24
endmode

The frambuffer (/dev/fb0) contains 3 images (640x1440) and is rotated 180º. Each pixel occupies 4 bytes encoded in the following order: BBGGRRAA where AA (alpha) is always FF.