RVL-CPU-20 (also referred to as LU64+, despite there being pre-LU64 consoles with this board) is the second major hardware revision of the Wii. It has simpler power circuitry, which resulted in all versions of IOS being updated for compatibility. These new IOSes were also pushed to RVL-CPU-01 consoles in the 3.3rev03 and 3.4 updates (3.5rev02 in Korea), and came along with fixes for the signing bug, /dev/flash access, and ES_DiVerify access.
They were once referred to as "unsoftmoddable" due to the cheaper power system slowing down IOS reloads and therefore breaking libogc, but this was easily fixed by updating libogc. boot2v4 also created issues in mini, which broke the HackMii Installer, but this was also easily fixed by updating mini.
- boot1c is now installed.
- boot2v4 is the new boot2 version.
- IOS3, IOS4, and IOS254 are now stubbed, even in cases where the latest update does not stub them
- Many older IOS versions (minor versions, not slots) no longer work due to simpler power circuitry, although a few, such as IOS15 and IOS16, can still be safely downgraded.