I was able to compile the binary on the board itself with tinycc (使用TinyCC在（milkv-duo）开发板内编写C程序调试):
tcc -r ssd1306.c -I .
tcc -r linux_i2c.c -I .
tcc -o ssd1306 main.c linux_i2c.o ssd1306.o -I .
./ssd1306 -I 128x64
./ssd1306 -c
./ssd1306 -m "Hello world!\nMilk-V Duo"
Thanks for detailed info you gave @AndrewDB