149
edits
Difference between revisions of "HOWTO-Debug-Endian-Issues"
Jump to navigation
Jump to search
HOWTO-Debug-Endian-Issues (view source)
Revision as of 09:24, 27 October 2022
, 09:24, 27 October 2022→Linux big-endian PowerPC emulation with QEMU: 3D games not that bad for big-endian debugging; from aquadran feedback
(→Linux big-endian PowerPC emulation with QEMU: Add some performance numbers) |
(→Linux big-endian PowerPC emulation with QEMU: 3D games not that bad for big-endian debugging; from aquadran feedback) |
||
| Line 24: | Line 24: | ||
* Security support updates have been discontinued for Debian 8 in late 2018. Older cryptographic ciphers and certificates (such as in TLS or SSH) in the base system may also cause various issues. For this reason, this VM should only be run ''on a local, trusted environment''. | * Security support updates have been discontinued for Debian 8 in late 2018. Older cryptographic ciphers and certificates (such as in TLS or SSH) in the base system may also cause various issues. For this reason, this VM should only be run ''on a local, trusted environment''. | ||
* ''' | * '''Audio content will be hard to debug''' on this environment, since QEMU has no sound card support for this architecture yet<ref>Actually, PPC audio support has been added in [https://gist.github.com/akemin-dayo/0e9bdcd74b2ad7f0bcf56e0680256103 an experimental QEMU fork]. It may also be possible to force the VM to use an external USB DAC, thanks to [https://qemu-project.gitlab.io/qemu/system/devices/usb.html QEMU USB pass-through], but this requires more work and is untested.</ref>. 3D games will also have a slow framerate, since QEMU only provides a limited, unaccelerated framebuffer for PPC. Make sure that the ScummVM component you want to debug/test won't be impacted by these limitations. | ||
* '''The bigger your host CPU clock rate, the better''': a 4 GHz CPU will bring some improvement over a 3 GHz CPU, which is itself much better than a 2 GHz CPU, and so on<ref>For reference, a full build of ScummVM with only the SCUMM engine takes around 26 minutes in QEMU on an Intel i7 or an Apple M1, while the same build on a native PowerPC G4 7447A takes 13 minutes (all single-threaded).</ref>. Note that QEMU emulation is mostly single-threaded, so having many CPU cores isn't really useful for this. | * '''The bigger your host CPU clock rate, the better''': a 4 GHz CPU will bring some improvement over a 3 GHz CPU, which is itself much better than a 2 GHz CPU, and so on<ref>For reference, a full build of ScummVM with only the SCUMM engine takes around 26 minutes in QEMU on an Intel i7 or an Apple M1, while the same build on a native PowerPC G4 7447A takes 13 minutes (all single-threaded).</ref>. Note that QEMU emulation is mostly single-threaded, so having many CPU cores isn't really useful for this. | ||