Dec 302008
 

The other day I found out that XCode breakpoints were not working anymore under iPhone Simulator, still worked fine with the device. Reinstalled XCode: nothing better. Removed all XCode settings files in the user directory as well as the /Library/Preferences directory: nothing better. Looking at the output from gdb I found it was reporting a certain number of errors related to finding symbols for the iPhone framework libraries: the messages read like this:

Unable to read symbols for "/System/Library/Frameworks/UIKit.framework/UIKit" (file not found).
warning: Unable to read symbols from "UIKit" (not yet mapped into memory).
warning: Unable to read symbols for "/System/Library/Frameworks/CoreGraphics.framework/CoreGraphics" (file not found).
warning: Unable to read symbols from "CoreGraphics" (not yet mapped into memory).
warning: Unable to read symbols for "/System/Library/Frameworks/OpenGLES.framework/OpenGLES" (file not found).
warning: Unable to read symbols from "OpenGLES" (not yet mapped into memory).
Program loaded.
Pending breakpoint 1 - ""aPointSystem.m:395" resolved
sharedlibrary apply-load-rules all


After a few google searches I realized a lot of people are reporting the same messages, but there was never a real solution on how to get rid of this and the rare solutions suggested to remove some rogue breakpoints and everything would be solved… So not so surprisingly I focused on solving this problem first because i thought it was very likely to be the reason for my breakpoints not working. Well yeah indeed if I remove all breakpoints all ‘file not found’ messages go away, but all debugging also goes away, as soon as the breakpoints are back, so are the messages !!

So after a couple days of scrambling I still had in the back of my mind the idea that the only thing I had done lately to the system was to upgrade the mac os X kernel to the newest voodoo kernel. Some rare intermittent crashes (see screenshots) occuring while debugging, together with the problem occuring only on the iphone smulator (hence host code and possible kernel hooks failures) and reinstallation/settings erasure independent it seemed to be a consistent explanation to my woes….

occasional Voodoo kernel panic

Sure enough, after I returned to the old kernel the breakpoints started working again, it turns out the ‘file not found’ messages are completely normal the reason being the iphone framework code is private to apple and therefore debug symbols are inexistent. You got to admit the ‘file not found’ messages are somewhat misleading.

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Dec 132008
 

So over thanksgiving I’ve taken some time to work a little more on my secret iPhone project (or I should just say “my secret project” abstracting the iPhone altogether since until recently almost no iPhone API’s were called), and I’m pretty glad I’ve made a little progress from the point where I was stuck for a while now. I’ve started implementing things in OpenGL ES in the hopes to see things go very fast and some impressive rendering speeds however I was pretty disappointed by the outcome, I’m guessing the bottleneck is the arithmetic I’m doing so I’ve started considering using the vfp for the iPhone.

Lately as a result I’ve been looking into using the hardware a little more and that probably means that I will have to rewrite some parts of the engine 🙁 to make hardware acceleration more doable. 

I thought I’d share my little bit of research on google which gave me the following pointer to a very good place to start in order to exploit the iPhone vfp:  

update: I’ve been researching a bit more and it seems the iPhone vfp is more specifically a vfp11 co-processor for the iPhone’s processor (ARM1176JZF), for which I pulled the doc on the arm website:

arm 1176jzf-s pdf doc

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Mar 202008
 

Today I was just approved for the iphone sdk developer program, which makes me one of a “select few” developers that can do native development on the iphone. I was pretty sure my application was going to be denied since there is nothing special about me or my application which could have made a difference. Anyways that’s very good news since that will give me a little head start to continue developing my app (for the moment I’m not giving any details about my app until I have something presentable and I know it’s going somewhere – or nowhere). After succesfully installing osX on my pc I was able to quickly port all my code over to the iphone sdk and I must say I was pretty impressed with it; it has all a developer could dream of to create apps really productively…

Anyways I haven’t been able to touch the sweet stuff yet as I’m still waiting on my order to be processed but will try to get back here to post some update.