StrongED on OMAP

Recently I’ve received a bug report against StrongED 4.69a1 running on OMAP.

Apparently there’s an Undefined instruction abort but the dump file sent to me doesn’t show any undefined instructions around the abort address.

So, my question is; is anyone running StrongED on OMAP and if so have you seen the above abort (it occurs when trying to create a new text)?

The abort was easy to reproduce, but slightly trickier to track down!

At &27624 there’s the instruction LDMNEIA R13!,{R0-R12,PC}^. This causes unpredictable behaviour when executed in user mode (The combination of loading the PC and using the ^ flag causes the CPU to try and restore the PSR to the value of SPSR, but there is no SPSR in USR32). On an Iyonix this “unpredictable behaviour” doesn’t seem to make the code malfunction in any noticeable way, but on OMAP it can cause strange things to happen – such as forcing the CPU into thumb mode. This is why the address of the crash (&3414?) doesn’t contain any undefined instruction – you were looking at ARM disassembly and not Thumb disassembly. The fact that the CPU often gets put into thumb mode also makes bugs like this a pain to track down, because you’ve got even less of an idea of where the CPU’s been or what registers are valid :(

If I get rid of the ^ then the code works fine. A quick search of the binary suggests that that’s the only bug of its kind in the program.

I’ll update my compatibility primer in a minute (I’ve already got MOVS pc, lr in there as being unpredictable in USR32 mode, but obviously didn’t think about LDM ...PC}^ being exactly the same)

Jeffrey has nailed it (again!)

After changing the instruction at &27624 !StrongED seems to run fine.

For those using !StrongED with the ‘dump’ mode it seems that assembler listings have 16 bit addresses. This can be changed to 32 bit addresses by adding a line “Lineos_Width:8” as the last line in !StrongED.Defaults.Modes.Dump.Choices.

Hope this will be of any help to others :-)

Now all i hope for is !StrongED to gain antialiased fonts like !Zap has ;-)

My, my…

I really need to look further into menus if I use software. !StrongED apparently does support anti-aliased fonts after all! I just needed to find the right settings.

The only difference is that !Zap renders the characters less spaced out which i.m.h.o. makes it a bit easier on the eyes.

I was trying out StrongED late last week. Although I found references in its help to its ability to use outline fonts, I couldn’t find anywhere in its user interface to configure fonts at all. Any pointers would be appreciated.

Dave, I agree that it is a bit obscure to find.

In the menu on the view of a file choose the bottom entry “basemode” then choose “Choices” → Font

This can be done for each mode seperately.

Jeffrey, thanks a lot for looking into this. As you say the code doesn’t seem to go wrong noticeably on the Iyonix (although I did see some redraw failures from time to time when opening a new text, which might be caused by this). I’m a bit surprised though that it slipped through when StrongED was 32-bitted.

As for outline fonts; whilst they can be used fine for reading text, editing is a bit of a hit and miss at the moment. A lot more work is needed to make editing with outline fonts work reliably.

To configure StrongED simply click on the ‘tick’ icon on the toolbar. Use Select to set the global choices, use Adjust to change the mode options.

If anyone has any further queries then please use the StrongED mailing list as that’s a more appropriate place for discussing StrongED matters.

I sent you it directly. I’ve managed to ioremap the gpmc area but im having trouble getting into supervisor mode in C!

os_swi0(OS_EnterOS) is crashing. Ideas?

ops wrong topic. Sorry!