The Mister SD is formatted as FAT32, and then the Linux filesystem is encapsulated inside a file, in linux/linux.img. This is called a "loopback" filesystem, if you see that word used anywhere.
I haven't been using Mister for very long, so I'm not familiar with older releases. I'm assuming that a read-only root filesystem is not normal, because that's not how it works on the current release. Don't do what I say here unless you get further confirmation that this diagnosis is correct.
Again: don't do this yet! Wait until people have seen this and said it sounds like a good idea.
First, back up any data you care about. Looking at the SD from Windows, the directories 'saves', 'savestates', and 'config' all have saved data you probably care about. The directories under 'games' may have images or ROM files you care about; you'll have loaded those yourself. Save all these directories somewhere before you do anything else.
Also grab a copy of linux/linux.img. You may need to restore that to get back to where you are now.
From there, I'm running on the assumption that the Linux loopback filesystem has somehow been damaged, and that Mister is mounting it read-only as a consequence. You could try to fix it from within Mister; this should be safe-ish as long as the filesystem is indeed read-only and not too badly corrupted. Note that the machine could stop booting if the linux filesystem is really hosed, so that's why you took those backups. You may end up having to re-flash the card, and you'll want to restore those.
Open a command prompt (F9 at the main menu), log in as root (the default password is '1', which should be changed if you haven't already done so), and type 'mount'. You should see something like this, possibly on the first line:
Code: Select all
/dev/loop8 on / type ext4 (rw,noatime,nodiratime)
along with a bunch of other irrelevant mountpoints. It's the "on /" that's critical; that's where your root filesystem is. No other line should say that exactly. If it's not "/dev/loop8" on /, abort, don't do anything else, and post back with what you see.
The quote there is what my line looks like; it's showing "rw" for "read/write", which is normal. If yours says "ro", that means it wasn't correctly mounted.
First, for safety, type this:
That makes sure the root filesystem is mounted read-only, so that the Mister system won't make any more changes to it, so you can safely operate on it with fsck. It probably already is, this is just an extra layer of safety net.
Then, type:
You probably want to say "y" to anything you see. When it's done, reboot IMMEDIATELY. (type "reboot" and hit enter.)
If it comes back up, go back to the command prompt and see if your mount line now says rw. If so, yay! You should be able to proceed with your updater of choice.
If it doesn't come back up, shut down the Mister, mount the card under Windows, and restore the linux/linux.img file you saved. Then try rebooting again; you should be back exactly where you were, none the worse for wear.
If you have to restore the linux.img, you'll probably end up having to reflash the card, rebuild your Mister installation, and then restore your save, savestate, and config directories, along with anything you saved from games.