10 ms·

Curious if this can work on the GBA ARM platform? I’m under the impression that the current gb emulator is a bit lacking.

cottsay 5y ago
I never got that far, but my goal was always to give it a shot. All of the ARM instructions used in this emulator are supported on that CPU. You'd have to implement interface adapters specific for the GBA hardware, but I structured the project such that you shouldn't need to untangle anything.
- ace2358 5y ago
  That’s awesome. Hopefully someone maybe picks it up because goomba is kind of terrible and weird :)
news_to_me 5y ago
I thought the GBA literally included the GB chip and just passed control to it though? Would be cool to see this run on the GBA still.
- Kipters 5y ago
  Some versions don't, like the GameBoy Micro and, in a sense, the Nintendo DS which includes the GBA CPU but not the GB one. There's already an emulator called Goomba that runs on the GBA, even in older GBA models it's useful because you can launch it from a GBA flashcart
- brirec 5y ago
  When playing an 8-bit GB game on a GBA that is indeed what happens. It even uses the Z80 chip for sound in GBA titles. That said, there is a homebrew GB emulator for GBA (Goomba), and at least one reason to use it: neither the Game Boy Micro nor the Nintendo DS can natively play 8-bit Game Boy games. As far as I understand it, the only reason why they can’t is because 8-bit Game Boy carts use 5V power and logic, but GBA carts use 3.3V power and logic, and there’s only so much power and switching circuitry you can fit into a pocket-sized gadget.
  - doubled112 5y ago
    I've always found the "include the old console in the new console" strategy for backward compatibility a really smart implementation idea. PS2 did the same thing for PS1.
    - Kipters 5y ago
      In a sense also the Wii (Wii was basically a GameCube with 1.5x the clock and extra hardware) and Wii U (3 Wii cores strapped together + both the new and Wii GPUs + extra hardware) did so
      - Schinken_ 5y ago
        For the same reason it is actually possible to play GameCube games on a Wii U (through homebrew in the vWii System)
        Kipters 5y ago
        In my opinion one of the best, if not THE best, ways to play GameCube games on modern screens
        ace2358 5y ago
        Is it through homebrew Wii? I thought it was kind of a VM situation but was still the WiiU in control (that’s how you can have the game pad work with GC games). Though I’m not sure. I would love to read a nice breakdown about Nintendont ( the GC comparability software for WiiU homebrew) because I think it’s pure magic.
        Kipters 5y ago
        One thing to note is that Nintendont is not for Wii U only, it's also useful for later Wii models that removed GC support. The Wii has two processors: the main PowerPC one which runs the game bare-metal dubbed Broadway, and a smaller ARM9 core hidden inside the GPU package dubbed Starlet which runs a separate firmware called IOS. The game running on Broadway accesses all the Wii hardware by sending requests to IOS - which also controls clocks etc. Wii U has a similar architecture with the Espresso and Starbuck respectively. On the Wii, Starlet also handles background network activity and WiiConnect 24. The Wii holds multiple IOS versions in its main NAND flash, and everytime a game loads the System Menu (the one with the channels) reads the required version from the game metadata and reboots both Broadway and Starlet into the game and correct IOS versions. This is why for example early games like Twilight Princess didn't light up the drive led bar when receiving messages like in more recent games: that game was stuck on IOS4, which didn't support that feature. Now, what happens when the user inserts a GameCube disk into a compatible Wii is that the System Menu loads a special IOS called MIOS. This disables access to all Wii-specific hardware, downclocks the CPU and GPU, sets up the memory layout and effectively turns the system into a GameCube (it's been a while, but I think it also completely disables Bluetooth so you can't even use the Wiimote to shut it down, you need to get up and walk to the machine to turn it off). In the initial versions it didn't scrub memory, so the Twiizer Hack happened: in GC mode you can only access 16 of the 64 MB memory, but using tweezers to manipulate the address lines they managed to "move" this window and dump it over the controller port serial, and found keys. IOS can and has been hacked or entirely replaced, the Twiizers team even wrote their own 100% free replacement, but other teams came up with hacked versions that i.e. redirected optical drive calls to USB devices, to enable piracy. Nintendont skips MIOS: it runs with IOS, so it has access to all the hardware as if it was a native Wii application, so it can access the SD, USB, Bluetooth and even the NAND flash or network if it wanted to. The Wii U works similarly: Starbuck runs a firmware called IOSU (not based on IOS). When starting the Virtual Wii mode, a process called cafe2wii is launched. This shuts down IOSU, lowers clocks, disables access to Wii U hardware and reboots into IOS80 to run the Wii System Menu. You can read more at hackmii.com, wiiubrew.org and wiibrew.org
- swetland 5y ago
  Probably challenging given that the GBA's ARM7TDMI core runs at about 17MHz. Perhaps doable if the graphics hardware as accessed from the ARM core can operate in the same modes the Z80 core uses (I forget if it's a strict superset, or what, exactly).
Narishma 5y ago
Can the GBA run Linux?
- Kipters 5y ago
  I remember running a version of uCLinux on my GBA SP back in 2006
- anyfoo 5y ago
  Not in the most meaningful sense of "natively and without heavy modifications", because the GBA's ARM lacks the proper MMU. You could always go the route to just emulate something that runs Linux, but it's probably not going to be very usable for anything.
  - bpye 5y ago
    You can configure Linux to run without an MMU - it seems like that should be doable?
    - anyfoo 5y ago
      Oh I didn't know, indeed: https://www.kernel.org/doc/Documentation/nommu-mmap.txt https://www.kernel.org/doc/Documentation/nommu-mmap.txt
- acjones8 5y ago
  Probably not, but there was a neat project from a while back that got an ancient version of UNIX running on it: https://web.archive.org/web/20060831141959/http://www.kernelthread.com/publications/gbaunix/ https://web.archive.org/web/20060831141959/http://www.kernel...

cottsay 5y ago

I never got that far, but my goal was always to give it a shot. All of the ARM instructions used in this emulator are supported on that CPU. You'd have to implement interface adapters specific for the GBA hardware, but I structured the project such that you shouldn't need to untangle anything.

ace2358 5y ago
That’s awesome. Hopefully someone maybe picks it up because goomba is kind of terrible and weird :)

news_to_me 5y ago

I thought the GBA literally included the GB chip and just passed control to it though? Would be cool to see this run on the GBA still.

Kipters 5y ago
Some versions don't, like the GameBoy Micro and, in a sense, the Nintendo DS which includes the GBA CPU but not the GB one. There's already an emulator called Goomba that runs on the GBA, even in older GBA models it's useful because you can launch it from a GBA flashcart
brirec 5y ago
When playing an 8-bit GB game on a GBA that is indeed what happens. It even uses the Z80 chip for sound in GBA titles. That said, there is a homebrew GB emulator for GBA (Goomba), and at least one reason to use it: neither the Game Boy Micro nor the Nintendo DS can natively play 8-bit Game Boy games. As far as I understand it, the only reason why they can’t is because 8-bit Game Boy carts use 5V power and logic, but GBA carts use 3.3V power and logic, and there’s only so much power and switching circuitry you can fit into a pocket-sized gadget.
- doubled112 5y ago
  I've always found the "include the old console in the new console" strategy for backward compatibility a really smart implementation idea. PS2 did the same thing for PS1.
  - Kipters 5y ago
    In a sense also the Wii (Wii was basically a GameCube with 1.5x the clock and extra hardware) and Wii U (3 Wii cores strapped together + both the new and Wii GPUs + extra hardware) did so
    - Schinken_ 5y ago
      For the same reason it is actually possible to play GameCube games on a Wii U (through homebrew in the vWii System)
      - Kipters 5y ago
        In my opinion one of the best, if not THE best, ways to play GameCube games on modern screens
      - ace2358 5y ago
        Is it through homebrew Wii? I thought it was kind of a VM situation but was still the WiiU in control (that’s how you can have the game pad work with GC games). Though I’m not sure. I would love to read a nice breakdown about Nintendont ( the GC comparability software for WiiU homebrew) because I think it’s pure magic.
        Kipters 5y ago
        One thing to note is that Nintendont is not for Wii U only, it's also useful for later Wii models that removed GC support. The Wii has two processors: the main PowerPC one which runs the game bare-metal dubbed Broadway, and a smaller ARM9 core hidden inside the GPU package dubbed Starlet which runs a separate firmware called IOS. The game running on Broadway accesses all the Wii hardware by sending requests to IOS - which also controls clocks etc. Wii U has a similar architecture with the Espresso and Starbuck respectively. On the Wii, Starlet also handles background network activity and WiiConnect 24. The Wii holds multiple IOS versions in its main NAND flash, and everytime a game loads the System Menu (the one with the channels) reads the required version from the game metadata and reboots both Broadway and Starlet into the game and correct IOS versions. This is why for example early games like Twilight Princess didn't light up the drive led bar when receiving messages like in more recent games: that game was stuck on IOS4, which didn't support that feature. Now, what happens when the user inserts a GameCube disk into a compatible Wii is that the System Menu loads a special IOS called MIOS. This disables access to all Wii-specific hardware, downclocks the CPU and GPU, sets up the memory layout and effectively turns the system into a GameCube (it's been a while, but I think it also completely disables Bluetooth so you can't even use the Wiimote to shut it down, you need to get up and walk to the machine to turn it off). In the initial versions it didn't scrub memory, so the Twiizer Hack happened: in GC mode you can only access 16 of the 64 MB memory, but using tweezers to manipulate the address lines they managed to "move" this window and dump it over the controller port serial, and found keys. IOS can and has been hacked or entirely replaced, the Twiizers team even wrote their own 100% free replacement, but other teams came up with hacked versions that i.e. redirected optical drive calls to USB devices, to enable piracy. Nintendont skips MIOS: it runs with IOS, so it has access to all the hardware as if it was a native Wii application, so it can access the SD, USB, Bluetooth and even the NAND flash or network if it wanted to. The Wii U works similarly: Starbuck runs a firmware called IOSU (not based on IOS). When starting the Virtual Wii mode, a process called cafe2wii is launched. This shuts down IOSU, lowers clocks, disables access to Wii U hardware and reboots into IOS80 to run the Wii System Menu. You can read more at hackmii.com, wiiubrew.org and wiibrew.org
swetland 5y ago
Probably challenging given that the GBA's ARM7TDMI core runs at about 17MHz. Perhaps doable if the graphics hardware as accessed from the ARM core can operate in the same modes the Z80 core uses (I forget if it's a strict superset, or what, exactly).

Narishma 5y ago

Can the GBA run Linux?

Kipters 5y ago
I remember running a version of uCLinux on my GBA SP back in 2006
anyfoo 5y ago
Not in the most meaningful sense of "natively and without heavy modifications", because the GBA's ARM lacks the proper MMU. You could always go the route to just emulate something that runs Linux, but it's probably not going to be very usable for anything.
- bpye 5y ago
  You can configure Linux to run without an MMU - it seems like that should be doable?
  - anyfoo 5y ago
    Oh I didn't know, indeed: https://www.kernel.org/doc/Documentation/nommu-mmap.txt https://www.kernel.org/doc/Documentation/nommu-mmap.txt
acjones8 5y ago
Probably not, but there was a neat project from a while back that got an ancient version of UNIX running on it: https://web.archive.org/web/20060831141959/http://www.kernelthread.com/publications/gbaunix/ https://web.archive.org/web/20060831141959/http://www.kernel...