Alek wrote an article about how to port PSP homebrew over to the latest 4.x kernel.

Quote:

As we spoke some days ago the 1.50 kernel would probably disappear. Therefore, we spoke about migrating homebrews to 3.xx kernels, and i linked to this post on ps2dev.

So, what’s new when porting to 4.xx kernels instead of 3.xx ones? Following the same guide as CpuWhiz on his post;

1. Homebrew must be in prx format. To do that, after the PSPSDK includes (include $(PSPSDK)/lib/build.mak), add this two lines:
BUILD_PRX = 1
PSP_FW_VERSION = 401

The last line (PSP_FW_VERSION) isn’t really needed in this case, just for the compilation when making #ifdef branches or not; but as 4.00/4.01 hasn’t included anything relevant on that affairs, you can skip that line.

2. Homebrew must be in user mode. On your main.c code, for the proper pbp compilation,
PSP_MODULE_INFO(“module1”, 0, 1, 0);

Remember that the PSP_MODULE_INFO system goes like this -> PSP_MODULE_INFO(“module_name”, mode, mayor_revision, minor_revision), and we put an “0” on mode for user mode; meanwhile 0x1000 would be for kernel mode. And also, add this line;
PSP_HEAP_SIZE_MAX();

Considering that you have a newer PSPSDK that can compile within it.

3. That would be enough for what it takes. Got any problem within running it, once compiled? Re-check latest steps from that ps2dev post to check for your kernel calls.

So, to sum up, due to the poor changes from 3.xx to 4.00/4.01, you just need to keep on the prx format, AND the user mode on the pbp code. Probably some of you already knew this, but bleh, this can’t be bad to have in mind, as one user commented on the “Bye Bye, 1.50” post.

Thanks to http://www.dcemu.co.uk for this interesting article.

http://alek.dark-alex.org/index.php?itemid=158