Q&A related to OS4

How do I run a shell script from AmiDock?
Even though you would usually use IconX to give a shell script an icon and have it run by clicking on it, this won't work in AmiDock. Instead, set the default tool to "execute" and select "Start from Shell".

I cant use Aminet with Ibrowse!
In the Pre-Release Ibrowse is a demo version and doesnt have support for FTP, you need to register it for that. Most aminet mirrors default to use ftp for file transfers, but many work through http too, just change the URL yourself, or use a mirror that defaults to http to begin with. Or an even better idea, register Ibrowse, you wont regret it :-)

Does the Prerelease include Petunia JIT 68k emulator?
No. Only interpretive emulator included, and it has nothing to do with the Petunia emulator. Those two emulators were developed independently. Final version will include both emulators for the sake of handling compatibility issues.

How do I install (pre)amigaOS4 and debian/linux on the same HD ?
Please read this article written by William White and submited to our articles section on how to go about doing it.

How to I stop/start my internet connection ?
To start, type addnetinterface "name of the interface" (e.g. eth3com) to stop, type in a shell netshutdown to see the status, type in a shell shownetstatus

After I have installed OS4 and reboot, I can't get further than the loading Kickstart screen
This can occur if your UBoot setting are incorrect. An example being the serial address settings. Make sure that they match EXACTLY to the install guide, but beware becuase they are very similar.

My internet connection keeps going dead when im browsing the web!
Theres a bug in the eth3com.device, you can improve the situation by typing "AddNetInterface" followed by the name of your interface e.g. eth0 into a shell. Hopefully this will be sorted out shortly and this FAQ can be deleted.

Why does it boot from CD even if the CD is not in the first position in Uboot boot options ?
After the kickstart is loaded, the Kickstart boots and looks for volumes to mount. If you have a CD in the drive and it has a higher boot priority than your hard drives boot partition it will boot from the CD. So if you leave a CD in your CD drive and it has a higher boot priority than your bootable partition then it will boot from that.

Can I use my old MUI keyfile to register the MUI that comes with OS4?
simple answer is yes :-)

I have 512Mb of RAM in my A1 but when I type avail I only see 132Mb of physical RAM and 388Mb of virtual RAM. Why is this?
Virtualised memory is necessary in OS4. We use different address ranges to differentiate between native PPC code and 68k code. So there's always some RAM directly mapped (the 128 MB here), and the rest is virtualised.

So not all of the address space is virtual(ised) then?
No. Some memory is kept that is mapped physically, i.e. the physical address matches the virtual address. This is to keep in sync with the original MEMF_PUBLIC flag which says the memory will not be (re)mapped.

Can the amount of physical/virtual memory can be set manually?
On the CSPPC/BPPC yes, but not on the A1. I guess I'll add an option to do that, though. Currently, it selects according to the size of main memory, with 128 being the largest.

So memory has to be assigned as virtual to maintain computability with 68K stuff, even though it really is physical memory and will still perform like physical memory?
Short answer: Basically yes.

Long answer: It works like this: Some memory is physically mapped, just like on old Exec.
OTOH, some of the physical memory is set aside to serve as pages for the virtual memory
system (This page pool is not mapped, so it's invisible to the CPU). Currently, this means that
these pages are just mapped somewhere in the address space to provide memory for virtual
addresses. As there's currently no pager, they remain there until unmapped.

Once we have a pager, this will move pages in and out of memory to disk, remapping existing
pages. That's why right now, you're limited to the physical memory you have (the virtual
memory is just a "reordering" of the current memory layout).

The point about 68k is as follows: The PPC can mark memory as executable. Only memory
with this attribute can hold code. So what we do is, we set aside some area of addresses
which have this attribute. PPC code is always allocated from this virtual region (and backed
up with memory from the page pool just like any virtual memory). So just by looking at the
address (actually, it's a bit more complicated, but boils down to this) we can determine if an
address holds PPC code or not.

This mechanism is used by all sort of "untyped" calls, for example Hooks. If you want to use a
hook in OS4, you just set h_Entry to the code you want to be called (68k or PPC), and use
utility.library/CallHookPkt. CallHookPkt determines if the code is PPC or not, and either
directly calls the function, or emulates it. The same works for interrupt handlers; you can
actually set a 68k function as interrupt handler. The code that determines the type is actually
quite fast, in the best case, it's just a table lookup, making this a viable solution.

The whole idea was to be able to make Hooks available where you just set the h_Entry
pointer, without the need to go through specific emulator traps. I didn't like the idea of having
to go through an emulator trap every time a PPC function is called (after all, 68k is to be
considered legacy). Plus, you don't need to change your source code, then.

Does OS4 support Altivec?
Short answer : Yes.

Long answer : When a task starts, it's launched with Altivec disabled, thus no vector
registers are stored during context switch. The first Altivec instruction then generates an
exception, and the enable bit is set. From then on, the task saves/restores Altivec context
whenever it is scheduled. vrsave is used to keep track of the registers.

How big should my workbench partition be?
Well the basic OS install itself should take up around 40MB of space, so set up a partition a bit bigger than that and you'll be fine. Personally I would use a 250MB partition leaving lots of space for future addons and the like.

Can I install OS4 on the same disk as Linux?
It is recommended to use separate drives for OS4 and Linux. However, if you have RDB (RigidDiskBlocks - AmigaOS partition table) on your hard drive then it is possible to install Debian and OS4 on the same drive.

It is easiest to install OS4 first and partition with MediaToolBox. The partition DOSTypes are as follows:

Linux system 0x4c4e5800 LNX
Linux swap 0x53575000 SWP

The full instructions are at Ross Vumbaca' site
http://members.optusnet.com/au/amigaone/ and it is recommended to follow these. Note that you can drop to a command line at the end of the Debian install and run the dd command from there,
rather than creating a boot floppy. Alternatively you can reboot and use OS4 if installed. These methods may be useful on floppyless systems.

You can use the "ide part" or "scsi part" command in U-Boot to view your partition table, which will also tell you whether it is MBR (DOS) or RDB (Amiga).

When will OS4 be released?
When it is done (tm)