All custom BIOS'es doesn't have passed protection checking by Holly, so G1 bus is blocked and any G1 devices doesn't work. I'm still not find solution for this.
For working G1-ATA and GD-ROM you can use only "sd_loader_with.bios" firmware for now
Just put DS_CORE.BIN on SD, for other data you can use HDD.
If you boot console from "sd_loader_with.bios", you need to run games from IP.BIN mode.
If you have working GD drive, you can burn boot loader to CD and just boot from original bios.
Once I get the BIOS passes Holly protection checking, I'll post an update, but for now nobody knows how to get around this problem.
For first I need to get working "boot_loader_wsc_bfont.bios", this BIOS setup all original syscalls and have full original fonts.
For "SD only" users, G1 bus is not a problem. I updated archives with release now (download it again) and add "ds_core_sd.bios" and "SD_DS_CORE.BIN" (need rename it to DS_CORE.BIN) it's not will be initialize G1 devices.
If you boot console from "boot_loader_wsc_bfont_sd.bios" and load "SD_DS_CORE.BIN" from SD, you can solve all old troubles for boot games from custom bios.