LinuxMD/linuxmd

源代码：https://github.com/LinuxMD/linuxmd

linuxmd - 适用于世嘉MegaDrive的Linux

这是个玩笑吗？

不

我需要什么？

• 一台世嘉MegaDrive
• Mega EverDrive Core 或 Pro（Pro版本尚未测试）（参见：https://krikzz.com/our-products/cartridges/）
• 连接EverDrive和电脑的USB线
• 花点时间去折腾

这个能在（普通）模拟器上运行吗？

很可能不行，模拟器需要模拟EverDrive特殊的SSF2映射器（为我们提供4MB RAM）、EverDrive的协议（允许MegaDrive从SD卡加载文件）以及EverDrive提供的定时器寄存器。项目中包含一个QEMU分支，它模拟了足够多的MegaDrive和EverDrive功能，让你无需真实硬件就能体验。但请注意，这并不能真正还原真实硬件的感觉，QEMU模拟CPU的速度过快。

构建说明

• 运行 ./buildtoolchain.sh 构建工具链。这使用了buildroot，但我们并没有用它构建根文件系统。buildroot是获取一份能生成68000可用二进制文件的m68k-linux工具链最省事的方法。
• 运行 ./builduboot.sh 使用工具链构建u-boot。
• 运行 ./buildmedtool.sh 构建 medtool，用于与EverDrive串口控制台交互。
• 运行 ./buildlinux.sh 构建Linux内核镜像。
• 运行 ./buildrootfs.sh 构建根文件系统erofs镜像。

针对模拟版本

• 运行 ./buildqemu.sh 构建QEMU
• 运行 ./runqemu.sh 运行QEMU并启动。

启动说明

• 将 u-boot/u-boot.bin、linux/vmlinux.lz4、smolutils/m68k.erofs 复制到你的EverDrive SD卡中
• 启动MegaDrive电源
• 将USB线连接到电脑（在MegaDrive关闭时连接可能也可以，但我遇到过问题）
• 查看你的dmesg，确保EverDrive被检测到。你应该看到类似下面的信息：

  [1135618.045606] usb 3-2: new full-speed USB device number 5 using xhci_hcd
  [1135618.255415] usb 3-2: New USB device found, idVendor=0483, idProduct=5740, bcdDevice= 2.00
  [1135618.255428] usb 3-2: New USB device strings: Mfr=1, Product=2, SerialNumber=3
  [1135618.255430] usb 3-2: Product: Mega EverDrive
  [1135618.255432] usb 3-2: Manufacturer: STMicroelectronics
  [1135618.255434] usb 3-2: SerialNumber: 00000000001A
  [1135618.307393] cdc_acm 3-2:1.0: ttyACM0: USB ACM device
  [1135618.307472] usbcore: registered new interface driver cdc_acm
  [1135618.307475] cdc_acm: USB Abstract Control Model driver for USB modems and ISDN adapters
  

• 在terminal模式下将 medtool 连接到你的EverDrive：

  ./medtool/medtool -p /dev/ttyACM0 -m terminal
  Opened serial port /dev/ttyACM0
  data out, 4 bytes --> 0x2b 0xd4 0x40 0xbf
  <-- data in, 4 bytes 0x5a 0x05 0x25 0x00
  core
  Creating socket and waiting for connection (minicom -D unix#/tmp/medtool)
  

• 按照提示操作，启动 minicom 并连接到 medtool 的unix socket
• 在EverDrive菜单中选中 u-boot.bin，按下一个按钮，然后按下 start game（见 everdrive_menu_uboot 图）
• 稍等片刻，你应该能在minicom中看到u-boot出现：

  Welcome to minicom 2.10
  
  OPTIONS: I18n
  Port unix#/tmp/medtool
  
  [?] Press CTRL-A Z for help on special keys
  
  md ! a b c
  
  U-Boot 2026.01-00675-g9da66c43e96b-dirty (Jun 24 2026 - 20:10:31 +0900)
  
  DRAM:  3.8 MiB
  SR is 0x2700
  copy from 00000000 to 00398000, 0x27f70 bytes (reloc_off 0x00398000)
  copied from 00000000 to 00398000, 0x27f70 bytes (reloc_off 0x00398000)
  clearing new bss from 003bd000 to 003bff70
  Doing relocation
  Relocation point of no return, new SP 0x003368d0, jump to 0x003a0370
  Core:  5 devices, 5 uclasses, devicetree: embed
  Loading Environment from NVRAM... *** Warning - bad CRC, using default environment
  
  In:    serial
  Out:   serial,vidconsole
  Err:   serial
  Hit any key to stop autoboot:  0 
  status; 0xa500
  status; 0xa500
  Loading vmlinux.lz4, 744178 bytes
  status; 0xa500
  Done
  Uncompressed size: 1270696 = 0x1363A8
  ELF overwrites reserved memory: 0x00000000 -> 0x0013ff35: -22
  new fdt 003392a8
  L s K
  Linux version 7.1.0-rc6-00250-g29f5b5b8fc12-dirty (daniel@kinako) (m68k-linux-gcc.br_real (Buildroot -gdb75a8eea0bd) 15.2.0, GNU ld (GNU Binutils) 2.46.0.20260210) #374 Wed Jun 24 22:12:37 JST 2026
  Flat model support (C) 1998,1999 Kenneth Albanowski, D. Jeff Dionne
  Generic DT Machine (C) 2024 Daniel Palmer
  OF: reserved mem: Reserved memory: No reserved-memory node in the DT
  Zone ranges:
    DMA      [mem 0x0000000000000000-0x00000000003fffff]
    Normal   empty
  Movable zone start for each node
  Early memory node ranges
    node   0: [mem 0x0000000000000000-0x00000000003fffff]
  Initmem setup node 0 [mem 0x0000000000000000-0x00000000003fffff]
  Kernel command line: console=ttyVDP0 console=ttyED0 root=/dev/edblk -- smolinit.getty=/dev/ttyED0 smolinit.getty=/dev/ttyVDP0 smolinit.hostname=md
  printk: log buffer data + meta data: 4096 + 8704 = 12800 bytes
  Dentry cache hash table entries: 1024 (order: 0, 4096 bytes, linear)
  Inode-cache hash table entries: 1024 (order: 0, 4096 bytes, linear)
  Built 1 zonelists, mobility grouping off.  Total pages: 1024
  mem auto-init: stack:all(zero), heap alloc:off, heap free:off
  SLUB: HWalign=16, Order=0-1, MinObjects=0, CPUs=1, Nodes=1
  NR_IRQS: 32
  clocksource: everdrive-timer: mask: 0xffff max_cycles: 0xffff, max_idle_ns: 29163075000 ns
  printk: console [ttyVDP0] enabled
  printk: console [ttyED0] enabled
  Calibrating delay loop... 0.72 BogoMIPS (lpj=5984)
  pid_max: default: 4096 minimum: 301
  Mount-cache hash table entries: 1024 (order: 0, 4096 bytes, linear)
  Mountpoint-cache hash table entries: 1024 (order: 0, 4096 bytes, linear)
  VFS: Finished mounting rootfs on nullfs
  everdrive fifo thread started
  Memory: 2532K/4096K available (1002K kernel code, 54K rwdata, 108K rodata, 72K init, 39K bss, 1368K reserved, 0K cma-reserved)
  devtmpfs: initialized
  clocksource: jiffies: mask: 0xffffffff max_cycles: 0xffffffff, max_idle_ns: 31854341414376613 ns
  clocksource: Switched to clocksource everdrive-timer
  workingset: timestamp_bits=30 (anon: 26) max_order=10 bucket_order=0
  (anon: 0)
  status 0xa500
  status 0xa500
  status 0xa500
  everdrive-blk everdrive-blk@0: Everdrive blk created for m68k.erofs, size is 90112
  erofs (device edblk): mounted with root inode @ nid 36.
  VFS: Mounted root (erofs filesystem) readonly on device 259:0.
  devtmpfs: mounted
  VFS: Pivoted into new rootfs
  Freeing unused kernel image (initmem) memory: 72K
  This architecture does not have kernel memory protection.
  Run /sbin/init as init process
  smolutils init (Jun 20 2026, 22:01:47)
  cmdline args:
  smolinit.getty=/dev/ttyED0
  Will start getty on TTY /dev/ttyED0
  smolinit.getty=/dev/ttyVDP0
  Will start getty on TTY /dev/ttyVDP0
  smolinit.hostname=md
  Hostname will be md
  environment variables HOME=/ TERM=linux
  mounting filesystems...
  mounted sysfs(sysfs) on /sys
  mounted proc(proc) on /proc
  mounted tmp(tmpfs) on /tmp
  mounted run(tmpfs) on /run
  Starting getty on /dev/ttyED0 with shell /bin/smolsh
  Starting getty on /dev/ttyVDP0 with shell /bin/smolsh
  smolsh / > ls -l
  random: crng init done
  dr-xr-xr-x    2 root     root           447 bin
  drwxr-xr-x    2 root     root             0 dev
  dr-xr-xr-x   61 root     root             0 proc
  drwxr-xr-x    2 root     root             0 run
  dr-x------    2 root     root           112 sbin
  dr-xr-xr-x   11 root     root             0 sys
  drwxr-xr-x    2 root     root             0 tmp
  smolsh / > ps
  USER       PID CMD
  root         1 init
  root         2 kthreadd
  root         3 pool_workqueue_release
  root         4 kworker/R-slub_flushwq
  root         5 kworker/0:0-events
  root         8 kworker/R-mm_percpu_wq
  root         9 everdrive_fifo
  root        10 ksoftirqd/0
  root        11 pr/ttyED0
  root        12 pr/ttyVDP0
  root        13 kworker/0:1
  root        14 kdevtmpfs
  root        15 kworker/R-writeback
  root        16 kworker/R-kblockd
  root        17 kswapd0
  root        18 kworker/u5:0
  root        19 kworker/u4:1-ttyED-ttyED
  root        20 kworker/u4:2-ttyED-ttyED
  root        21 kworker/0:1H-kblockd
  root        24 getty
  root        25 getty
  root        26 smolsh
  root        27 smolsh
  root        29 kworker/u4:3-ttyED-ttyED
  root        30 ps
  root        31 kworker/0:0H
  root        32 kworker/u4:0-ttyED-ttyED
  smolsh / > 
  

  加载和解压内核会花费一些时间。请耐心等待！ 注意：目前速度非常慢。我手头的一个12MHz 68000系统都比现在的MegaDrive好用很多。这需要一些优化。与EverDrive FIFO的交互非常慢。

但如果这只是通过串口实现，那有什么意义呢？谁都能做到。

嗯，还有一套利用MegaDrive视频输出的炫酷控制台。它甚至拥有漂亮的滚动效果.. vdpconsole

• 右上角有一个绿色方框，那是“心跳”指示器，会闪烁以表明内核正在运行。
• 绿色方框下方还有一个红色方框，那是磁盘活动指示灯。