#48031 - chishm - Sat Jul 16, 2005 9:03 am
Hi,
I have run into a problem. I need to be able to write to the GBA ROM address space to access the CF cards. This is fine for programs that are built using DevKitARM, as it enables these writes. However, I need to be able to write at startup, from ASM code, without using ds_arm9_crt0, using the ARM7. Is this possible? If so, what is the easiest, shortest way to do this?
If I can only enable write access using the ARM9, what is the least amount of code needed to do this? I have tried looking through ds_arm9_crt0 to see how it does it, but a lot of the code does not seem applicable, but I don't know which parts.
Thanks for any help,
Chishm
EDIT: It seems I can read and write the GBA cart in DS mode from the ARM7. I am not sure about the SRAM though. I will keep working on it.
EDIT2: Of course, the cart has no SRAM! I assumed it would just have 0 bytes when read (like in GBA mode) but it doesn't seem to be the case. Oh well.
I have run into a problem. I need to be able to write to the GBA ROM address space to access the CF cards. This is fine for programs that are built using DevKitARM, as it enables these writes. However, I need to be able to write at startup, from ASM code, without using ds_arm9_crt0, using the ARM7. Is this possible? If so, what is the easiest, shortest way to do this?
If I can only enable write access using the ARM9, what is the least amount of code needed to do this? I have tried looking through ds_arm9_crt0 to see how it does it, but a lot of the code does not seem applicable, but I don't know which parts.
Thanks for any help,
Chishm
EDIT: It seems I can read and write the GBA cart in DS mode from the ARM7. I am not sure about the SRAM though. I will keep working on it.
EDIT2: Of course, the cart has no SRAM! I assumed it would just have 0 bytes when read (like in GBA mode) but it doesn't seem to be the case. Oh well.