Hacking Updating to EZ Flash IV Kernel 2.x

[rs1n]

It has been a while since I tinkered with my GBA, but I recently got interested in it again and found out that there is now a 2.05 kernel that supposedly supports micro SD cards. Does this mean I can use a micro/mini SD adapter? What happens to my existing GBA ROM files -- will I have to delete my old ROMs and re-transfer them (without the EZ Client patches)?

 

[rs1n]

I didn't bother to test the 2.05 firmware with the previously pre-patched GBA files. Instead, I just copied over unmodified ROM files and they ran fine. However, I did run into an issue:

I have the old miniSD version of EZ Flash IV (white cover) and had previously used the 1.72RESET firmware. I also have a second card that was using 1.77 (which apparently supported microSD cards inside a micro-to-mini adapter) and contained a 16GB SDHC card. I was NOT able to update from 1.77 to 2.05. Instead, I had to use my 2GB miniSD card to update to 2.05. However, after updating to 2.05, the miniSD card was left in there, and my GBA booted to the start screen for EZ Flash IV, only to then have black lines (and eventually a black screen) suggesting that my miniSD card was either not compatible or no longer supported (even though it works fine in the other flash card with 1.72RESET). Now that I think about it, I think the reason I kept two different firmwares was for this reason. Is it the case that after 1.72, only micro cards were supported (or something similar)?

What does this mean for future firmwares? Do I need to keep my miniSD card around for the sole purpose of firmware upgrades? Has anyone successfully used a micro SDHC card to do a firmware upgrade while under the newer 2.x firmwares? Or must it be regular micro SD?

 

[FAST6191]

The micro to mini adapter thing is not a software issue -- SD, miniSD and microSD all read and write in the same ways. It is just that for some reason the micro to mini adapters are so terrible that they are advised against.

SDHC reads differently so it is not a surprise that you would have had to do an update from SD first (it is not like the EZ4's little boot loader would have suddenly known about SDHC after all these years).

Also yeah the SDHC supporting kernels seem to have issues with older SD format cards -- some have them working but others don't, I don't have any patterns in this at this point as to what means what.

I don't know offhand if the update program got SDHC support as part of it all. I would keep a compatible 2 gig or less miniSD setup around though.

 

[rs1n]

The micro to mini adapter thing is not a software issue -- SD, miniSD and microSD all read and write in the same ways. It is just that for some reason the micro to mini adapters are so terrible that they are advised against.

SDHC reads differently so it is not a surprise that you would have had to do an update from SD first (it is not like the EZ4's little boot loader would have suddenly known about SDHC after all these years).

Well, I tried using the card that had kernel 1.77 (which was already working with the micro SDHC card) to update to 2.05 and it never was able to update (hence using the mini card from my other EZ Flash IV cart to do the update). It just seemed strange that 1.77 worked fine playing games from and saving to a micro SDHC card, but was not able to do the firmware update with micro SDHC.

Also yeah the SDHC supporting kernels seem to have issues with older SD format cards -- some have them working but others don't, I don't have any patterns in this at this point as to what means what.

I don't know offhand if the update program got SDHC support as part of it all. I would keep a compatible 2 gig or less miniSD setup around though.

Sound advice -- I will definitely keep my mini cards around just in case.

EDIT: Also, it seems formats changed at some point, too. Kernel 1.72 was still using FAT16 whereas 1.77 and higher was using FAT32.

 

[kuwanger]

It just seemed strange that 1.77 worked fine playing games from and saving to a micro SDHC card, but was not able to do the firmware update with micro SDHC.

The bootloader (that includes the kernel updater) is a small program that never gets updated to avoid possible corruption issues on a kernel update. The kernel itself takes care of loading games so was updated at some point to support FAT32 and larger filesystems. There's at least a few versions of the bootloader (one card I have will attempt updating the kernel even if no kernel is included, erasing the active one), so maybe some were updated at some point to support SDHC natively? In any case, yea, micro->miniSD adapters are flaky, and I'm lucky I've generally had luck with the one I have.

 

[rs1n]

The bootloader (that includes the kernel updater) is a small program that never gets updated to avoid possible corruption issues on a kernel update. The kernel itself takes care of loading games so was updated at some point to support FAT32 and larger filesystems. There's at least a few versions of the bootloader (one card I have will attempt updating the kernel even if no kernel is included, erasing the active one), so maybe some were updated at some point to support SDHC natively? In any case, yea, micro->miniSD adapters are flaky, and I'm lucky I've generally had luck with the one I have.

Thanks for the explanation -- it makes much more sense to me now.