Changes

== How it works ==

== How it works ==

BootMii-boot2 is a modified version of [[boot2]]'s [[NANDLoader]], which is loaded by [[boot1]], which is loaded by [[boot0]]. boot0 is part of [[Hollywood]] and read-only. boot1, although stored on the [[NAND]], is signed by a value in write-once memory and therefore cannot be changed without rendering a console unable to boot. boot2, however, can be modified (with some restrictions). This means it can be hacked, updated, and corrupted. BootMii hijacks the [[boot process]] before the normal boot2 is run, optionally allowing code to be run directly from the SD Card. This has many advantages, such as making it very difficult to [[brick]], and slowing Nintendo from blocking homebrew. Unfortunately, the only way we could completely stop Nintendo from blocking homebrew is by patching updates on-the-fly, or somehow preventing overwriting boot2. Along with the [[4.2]] update, Nintendo released a new version of boot2 ([[boot2v4]]); there is nothing in boot2v4 that prevents BootMii from working, but it will overwrite an existing BootMii installation when it is installed.

BootMii-boot2 is a modified version of [[boot2]]'s [[Starlet ELF Loader|ELF loader]], which is loaded by [[boot1]], which is loaded by [[boot0]]. boot0 is part of [[Hollywood]] and read-only. boot1, although stored on the [[NAND]], is signed by a value in write-once memory and therefore cannot be changed without rendering a console unable to boot. boot2, however, can be modified (with some restrictions). This means it can be hacked, updated, and corrupted. BootMii hijacks the [[boot process]] before the normal boot2 is run, optionally allowing code to be run directly from the SD Card. This has many advantages, such as making it very difficult to [[brick]], and slowing Nintendo from blocking homebrew. Unfortunately, the only way we could completely stop Nintendo from blocking homebrew is by patching updates on-the-fly, or somehow preventing overwriting boot2. Along with the [[4.2]] update, Nintendo released a new version of boot2 ([[boot2v4]]); there is nothing in boot2v4 that prevents BootMii from working, but it will overwrite an existing BootMii installation when it is installed.

The space normally allocated for the NANDLoader is split into two sections itself for technical reasons; the first section is a custom NANDLoader that loads the second section. The second section checks to see if an SD card is inserted; if so, it loads <code>/bootmii/armboot.bin</code> and executed it. Otherwise, it loads the real boot2, which remains intact when BootMii-boot2 is installed.

The space normally allocated for the ELF loader is split into two sections itself for technical reasons; the first section is a custom ELF loader that loads the second section. The second section checks to see if an SD card is inserted; if so, it loads <code>/bootmii/armboot.bin</code> and executed it. Otherwise, it loads the real boot2, which remains intact when BootMii-boot2 is installed.

BootMii also only installs into the first copy of boot2. There are two major advantages to this: first, if the installation is interrupted, the second copy will still function normally to boot; second, when boot2 is loaded by [[BC]], an updated version of BC will reject BootMii due to an invalid signature, but the second copy can still be loaded fine. For versions of BC with fakesigning, [[mini]] includes code to go directly to boot2 to ensure [[MIOS]] loads fine.

BootMii also only installs into the first copy of boot2. There are two major advantages to this: first, if the installation is interrupted, the second copy will still function normally to boot; second, when boot2 is loaded by [[BC]], an updated version of BC will reject BootMii due to an invalid signature, but the second copy can still be loaded fine. For versions of BC with fakesigning, [[mini]] includes code to go directly to boot2 to ensure [[MIOS]] loads fine.