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DS development > Shared Library in wram ARM7

#162020 - hacker013 - Sat Aug 23, 2008 12:10 pm

Hey,

I'm buzy with Mighty Maxs os but i game by a problem, the arm9 wram is to small to load a kernel with libfat so i want to load that library in the wram of arm7 and so that the kernel can use it, and also other programs.

Anybody an idea to do this??
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#162021 - eKid - Sat Aug 23, 2008 1:14 pm

ARM9 WRAM being mainram? which is 4MB? The ARM7 WRAM is 64KB+32KB. Too small for anything major.

#162023 - hacker013 - Sat Aug 23, 2008 2:55 pm

eKid wrote:
ARM9 WRAM being mainram? which is 4MB? The ARM7 WRAM is 64KB+32KB. Too small for anything major.


no, ARM9/ARM7 wram = 32KB and i have given ARM9 32KB but it is to small to have libfat include zo i want to load libfat + dldi in ARM7 wram (64kb) because the main ram is to execute user programs.

WRAM ARM9/ARM7 (32kb) = 0x3000000
WRAM ARM7 (64kb) = 0x3800000
Main RAM = 0x2000000

see: http://nocash.emubase.de/gbatek.htm#dsmemorymaps
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#162024 - tepples - Sat Aug 23, 2008 3:11 pm

There are two ways to slim libfat's disc I/O code:
  • Cut out the built-in drivers. This has already happened in the next libfat.
  • Shrink the DLDI space to 16 KiB. This breaks compatibility with the SLOT-2 G6, which has a big DLDI because its controllerless NAND chip needs big error-correction lookup tables, but I don't think a lot of people have that card.

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#162025 - hacker013 - Sat Aug 23, 2008 3:40 pm

tepples wrote:
Shrink the DLDI space to 16 KiB. This breaks compatibility with the SLOT-2 G6, which has a big DLDI because its controllerless NAND chip needs big error-correction lookup tables, but I don't think a lot of people have that card.


How do i do that??

EDIT:

I've compiled the kernel with all fat library:

libfat (normal) = 80 kb kernel
libfat (stripped) = 97 kb kernel
GBA_NDS_FAT (zonder dldi) = 34 kb

i don't unstand something, why is the stripped version from libfat bigger then the normal one??
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#162035 - hacker013 - Sat Aug 23, 2008 7:44 pm

has nobody a solution for this??, i need this....
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#162060 - simonjhall - Sun Aug 24, 2008 3:56 pm

I couldn't get libfat working for ARM7 when I last tried and instead did some IPC lovin' in order to get my ARM7 code to read stuff off disk. Things may have changed since, but here's the thread I started a while back:
http://forum.gbadev.org/viewtopic.php?t=12398&
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#162133 - hacker013 - Tue Aug 26, 2008 6:40 pm

simonjhall wrote:
I couldn't get libfat working for ARM7 when I last tried and instead did some IPC lovin' in order to get my ARM7 code to read stuff off disk. Things may have changed since, but here's the thread I started a while back:
http://forum.gbadev.org/viewtopic.php?t=12398&


it helped much but it didn't resolve the problem because the loader won't load the kernel anymore:(
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