View source for HAI-IOS

HAI-IOS (sometimes also called IOS255) is a heavily modified IOS used for the [[WiiMode]] in [[cafe2wii#HAI|HAI mode]]. It is bundled individually with each HAI title as a giant ELF file containing every IOS module.

== Modules ==
Most modules are very similar to the modules found in normal IOS versions. There are some exceptions listed below.

=== DI2SD ===
This replaces the DI module. DVD commands sent to '''/dev/di''' are emulated, and disc content is read from either MLC or UMS (using '''/dev/usb/msc''').

=== OHCI1 ===
This is a modified version of the OHCI1 module which handles communicating with the [[GamePad]]. It emulates HCI to handle virtual Bluetooth controllers which can be controlled with the GamePad.

=== SDI ===
This modified SDI module adds '''/dev/sdio/MLC01''' to allow reading and writing to the MLC, which is used by DI2SD.

== Hai params ==
The Wii U mode passes some parameters to this IOS which are referred to as "HaiParam" or "Hai params" (see [[cafe2wii#HAI|HAI mode]]).

=== Format ===
These parameters are stored in memory at 0xfffff000 and their format is described below.

==== Header ====
{| class="wikitable"
|-
! Start
! Length
! Description
|-
| 0x00
| 4
| Magic value: "Hai" (0x48616900)
|-
| 0x04
| 2
| Total size of the parameters (including header) in bytes
|-
| 0x06
| 2
| Parameter count
|}
The parameters follow after the header.

==== Parameter ====
{| class="wikitable"
|-
! Start
! Length
! Description
|-
| 0x00
| 2
| ID (see table below)
|-
| 0x02
| 2
| Size of parameter data in bytes
|}
The parameter data follows after the structure described above.

==== Parameter IDs ====
{| class="wikitable"
|-
! ID
! Description
|-
| 0x0
| Ticket of the title to boot
|-
| 0x1
| TMD of the title to boot
|-
| 0x100
| This is a string in the following format: <code>target:/path</code>.<br>Where target is either <code>mlc</code>, <code>usb</code>, <code>ahci</code> or <code>file</code> and path is the path to the imginf.bin file containing offsets to the nfs files (usually <code>/shared2/sys/hai/imginf.bin</code> on the slccmpt).
|-
| 0x101
| DI2SD "umsblk devId" (0x10 bytes)
|-
| 0x200
| DI2SD "keep-alive" (4 byte integer which is either 0 or 1)
|-
| 0x201
| APD (Auto Power Down) seconds (4 byte integer)
|-
| 0x300
| DRC controller on or off (1 byte which is always set to 1 by the IOSU)
|}

=== Syscall 7A ===
To retrieve these parameters HAI-IOS has an additional syscall in the following format: <code>IOSError syscall_7a(u16 id, void *data, u32 *size)</code>.

== Companion File ==
The Companion file usually <code>/shared2/sys/hai/imginf.bin</code> on the slccmpt contains the information about the extends of the nfs files.

=== Format ===
The companion file starts with a 8 byte header, followed by a variable number of extends and ends with a 1 byte footer
==== Header ====
The companion file starts with a 8 byte header
{| class="wikitable"
|-
! Start
! Length
! Description
! Example
|-
| 0x00
| 4
| Number of extends
| 1
|-
| 0x04
| 2
| Address Unit Base
| 0x13
|-
| 0x06
| 2
| Seems to be ignored by HAI-IOS, but had same value as the Address Base Unit
| 0x13
|}

The Address Unit is obtained by raising 2 to the power of the address unit base: pow(2,address_unit_base) or just <code>1<<address_unit_base</code>

==== Extends ====
The header is followed by the Array of Extends
The format of one extend is:
{| class="wikitable"
|-
! Start
! Length
! Description
! Example
|-
| 0x00
| 4
| Start Address
| 0x0000a575
|-
| 0x04
| 4
| Length
| 0x00000684
|}

The start address and length of an extend needs to be multiplied by the address unit obtained from the header to obtain the byte address, which can be divided by the lba size to obtain the lba address:

start_lba = start_address * pow(2,address_unit_base) / lba_size

==== Footer ====
The extends are followed by one byte with varying values, which is also ignored by HAI-IOS