MediaWiki:Common.css

2023-02-20T12:45:35Z

Administrateur:

/* Le CSS placé ici sera appliqué à tous les habillages. */
.breakout {
float: right;
border: 1px solid #888;
background: var(--color-surface-0);
padding: 0.2em;
}

@media screen and (max-width: 893px) {
.breakout {
display: none;
}
}

.research {
background: var(--background-color-framed);
}

.skin-citizen-dark .breakouttitle {
text-align: center;
background: #1a252d;
border-top: 1px solid #6a6;
border-bottom: 1px solid #6a6;
}

.skin-citizen-light .breakouttitle {
text-align: center;
background: #eaecf0;
border-top: 1px solid #6a6;
border-bottom: 1px solid #6a6;
}

.skin-citizen-light .mw-footer {
background: #ffffff;
}

.skin-citizen-dark .mw-footer {
background: #131a21
}

.skin-citizen-dark .last-modified-bar-content {
background: #131a21;
}

.skin-citizen-light .last-modified-bar-content {
background: #f8f9fa;
}

.skin-citizen-dark .last-modified-bar {
background: #131a21;
}

.skin-citizen-light .last-modified-bar {
background: #f8f9fa;
}

.skin-citizen-light .mw-footer a.external {
color: #000000;
}

.skin-citizen-dark .mw-footer a.external {
color: #cfdee8;
}

.skin-citizen-light .online a {
color: #000000;
}

.skin-citizen-dark .online a {
color: #cfdee8;
}

.skin-citizen-light #footer-places-privacy a {
color: #000000;
}

.skin-citizen-dark #footer-places-privacy a {
color: #cfdee8;
}

.skin-citizen-light #footer-places-about a {
color: #000000;
}

.skin-citizen-dark #footer-places-about a {
color: #cfdee8;
}

.skin-citizen-light #footer-places-disclaimer a {
color: #000000;
}

.skin-citizen-dark #footer-places-disclaimer a {
color: #cfdee8;
}

.skin-citizen-light #footer-info-0 {
color: #000000;
}

.skin-citizen-dark #footer-info-0 {
color: #cfdee8;
}

MediaWiki:Common.css

2023-02-20T12:44:53Z

Administrateur:

2023-02-20T12:40:01Z

Administrateur:

MediaWiki:Common.css

2023-02-20T12:38:54Z

Administrateur:

MediaWiki:Citizen-footer-desc

2023-02-20T12:38:19Z

2022-09-13T13:39:59Z

Administrateur:

[[Gotcha Force | ← Gotcha Force]]

''This article is for the DOL file format. See [[DOL (Gotcha Force)]] for current research on Gotcha Force DOL.''

{{ToDo| 1 | Better description sections. }}
{{Research | 3 | We need to fix bug with bad align.}}

'''DOL''' files (from the GameCube codename '''dol'''phin) are files found in [[GCM (File format)|iso/GCM]] GameCube and Wii files. Observations below concern only GameCube dol. Before being a dol the file was in ELF file format compiled from C sources with the GameCube SDK. All libs are staticly linked but in some dols we found some kind of external code loaded in the REL format.

== Boot Info 2 (BI2) dol configuration ==

For performances optimizations it is advisable to keep a max loaded length of 4Mb. This restriction is enabled by default with the DolLimit setting set to 4Mb in the BI2. This limit is often disabled by developpers. Code in .rel can be dynamically relocated and loaded by SDK OS lib (OSSetBootDol).
* In developpement boards we can map sections in virtual memory up to 0x81200000.
* In production boards we can map sections in virtual memory up to 0x80700000.
After this limits the apploader will raise an error.

== Format ==
The dol is a [[GCM (File format)|iso/GCM]] GameCube system file and is placed independently of the mini DVD user space (FST). The dol offset is stored in the boot.bin:0x420 at the beginning of the GCM/iso.

=== Header ===

The dol [http://wiki.tockdom.com/wiki/DOL_(File_Format) header] has a length of 0x100 bytes which describe how the dol must be loaded in virtual memory and how to prepare this memory.

{| class="wikitable"
!colspan="3"| Dol header
|-
! Offset !! Length !! Description
|-
| 0x000 || style="width:10%;" | 4 × 18 || Sections offsets - It tells where the section datas begin relative from the dol start. 0 for unused section.
|-
| 0x048 || 4 × 18 || Sections virtual addresses - It tells where we load section datas in virtual memory. 0 for unused section.
|-
| 0x090 || 4 × 18 || Sections length in bytes. 0 for unused section.
|-
| 0x0d8 || 4 || bss virtual address - Where bss start in virtual memory. bss areas are 0 initialized.
|-
| 0x0dc || 4 || bss length in bytes.
|-
| 0x0e0 || 4 || Entry point - Virtual address where we start executing when the dol has been loaded. This function shouldn't terminate.
|-
| 0x0e4 || 0x1c || Padding.
|-
| 0x100 || colspan="2"| Header end. Start of section datas.
|}

The first 7 sections are .text section containing executable code. We can find interrupts handlers or padding in it.

The 11 next sections are for .data containing initialized datas.

The .bss interval can contain .data or .text sections in it. If this is the case then the .bss is splited to not override existing sections and only out parts are keeped.

All section have to be aligned to 32 bytes. The [https://www.gc-forever.com/wiki/index.php?title=Apploader apploader] align all section length to upper 32 bytes

=== Memory organization ===
[https://www.gc-forever.com/yagcd/chap4.html#sec4 Yet Another GameCube Documentation / YAGCD] provide a very good documentation on memory organization.

==== Memory global organization ====

Global memory organization describe how addressing used in the dol allow to access the differents GameCube hardware composants. This is really interesting to understand the bus / interfaces access.

{| class="wikitable"
! colspan=4 | Memory mapping
|-
! Begin !! End !! Length !! Description
|-
| 0x00000000 || 0x017fffff || 24MB || Physical address of the RAM
|-
| 0x80000000 || 0x817fffff || 24MB || Logical address of the RAM, cached
|-
| 0xC0000000 || 0xC17fffff || 24MB || Logical address of the RAM, not cached
|-
| 0xc8000000 || || 2MB || Embedded Framebuffer (EFB)
|-
| 0xCC000000 || || || Hardware registers
|-
| 0xCC000000 || || || CP - Command Processor
|-
| 0xCC001000 || || || PE - Pixel Engine
|-
| 0xCC002000 || || || VI - Video Interface
|-
| 0xCC003000 || || || PI - Processor Interface (Interrupt Interface)
|-
| 0xCC004000 || || || MI - Memory Interface
|-
| 0xCC005000 || || || AI - Audio Interface
|-
| 0xCC006000 || || || DI - DVD Interface
|-
| 0xCC006400 || || || SI - Serial Interface
|-
| 0xCC006800 || || || EXI - External Interface
|-
| 0xCC006C00 || || || Streaming Interface
|-
| 0xCC008000 || || || GX FIFO (Graphic display lists)
|-
| 0xe0000000 || 0xe0003fff || 16k || L2 Cache
|-
| 0xfff00000 || || 1MB || IPL (mapped here at bootup)
|}

Hardware registers length and composition is detailed [https://www.gc-forever.com/yagcd/chap5.html#sec5 here].

==== User program area (dol) ====
As seen above the dol is mapped in the 24MB of RAM in virtual cached address space from 0x80003100 to 0x80700000 in production boards, and 0x81200000 in development boards.

The first 0x3100 bytes contains system informations [https://www.gc-forever.com/yagcd/chap4.html#sec4.2.1 ("Dolphin OS Globals")] with globals variables and also interrupts handlers specific to powerpc architecture. This informations are interesting when creating a dol loader resolving cross references inside the code.

{| class="wikitable"
! colspan=4 | Memory map
|-
! Adress !! Description
|-
| 0x80003100 || Start of mapped sections .text (usually)
|-
| 0x80003140 || Entry point (early SDK v1.0 applications)
|-
| ? || Stack - After the last section with a default length of 0x10000 bytes
|-
| ? || ArenaLo - Bottom of the Area initialized by the OS (SDK) after the Stack
|-
| 0x81200000 || Load Address of the Apploader
|-
| 0x81300000 || Load Address of Bootrom/IPL
|-
| ? || ArenaHi - Top of the Area initialized by the OS (SDK) stuck to the FST
|-
| ? || FST - Variable length - Stuck to the end of virtual cached memory space.
|-
| 0x81800000 || End of the virtual cached memory space (24MB)
|}

The Area contains the apploader and the bootrom/IPL. This area is allocated by the SDK api and is used to create and destroy Heaps in it.

The dol can be mapped from 0x80003100 to 0x80700000 in production boards leaving 7.3 MB for the program.

The FST is loaded in virtual memory deppending to it's position from the dol in the [[GCM (File format)|GCM/iso]]:
* FST_offset(iso) < dol_offset(iso) -> FST_virtual_address > dol_virtual_address
* FST_offset(iso) > dol_offset(iso) -> FST_virtual_address < dol_virtual_address

==== Sections ====

The PowerPc Embedded Application Binary Interface (EABI) describe 4 special registers:
* R1 is the stack pointer. We substract the space needed from it when entering in a function (Stack Frame). Terminal functions (thoose which don't call any functions) don't always need a frame.
* R2 is the read only Small Data Anchor __SDA2_BASE__ addressed with a signed short offset. It correspond to the .sdata2 (initialized constants) or .sbss2 (uninitialized constants).
* R13 is the Read / Write Small Data Anchor __SDA_BASE__ also addressed with a signed short offset. It correspond to the .sdata (initialized variables) or .sbss (uninitialized variables).
* R0 when used with an offset don't care about it's value. It allow to address 0x8000 first bytes of memory space and 0x7fff last bytes (signed short).

As said above SDA are used with a signed short offset (-0x8000 +0x7FFF). When we reach the entry_point then R1 R2 and R13 are pointer in the Bootrom/IPL. The first function __init_registers initialize them for executing the dol and we can see that it's set to the beginning of some .data and .bss sections.

We found this section originally build in the ELF32 file format:
* .ctors
* .dtors
* .rodata
* .data
* .bss
* .sdata (should correspond to -0x8000(R13)
* .sbss
* .sdata2 (should correspond to -0x8000(R2)
* .sbss2
* Followed by the stack (by default 0x10000 bytes length)
* Followed by ArenaLo initialized by the SDK
* Apploader loaded at address 81200000
* Bootrom/IPL loaded at address 81300000
* ArenaHi stuck to the FST
* FST stuck to the end of memory (81800000)

The SDK offer two functions for handling Arena: OSAllocFromArenaHi & OSAllocFromArenaLo. But the main program initialize a number of Heaps in it and Create / Destroy them as it need.

== DI - DVD Interface ==
The driver handling DVD accesses use the chip [https://wiibrew.org/wiki/Hardware/Disc_Drive#Hardware MN102] documented on [https://www.gc-forever.com/yagcd/chap5.html#sec5.7 yagcd]. The Hitmen team has programmed a plugin for it: [http://hitmen.c02.at/html/gc_releases.html MN102 IDA Pro].

Some more documentation on [http://hitmen.c02.at/files/docs/gc/Ingenieria-Inversa-Understanding_WII_Gamecube_Optical_Disks.html disc reads].

== EXI - External Interface ==
[https://github.com/dolphin-emu/dolphin/blob/master/Source/Core/Core/HW/EXI/EXI_Device.h Dolphin Emulator sources] show how EXI is used: MemoryCard, MaskROM, AD16, Microphone, Ethernet, AGP, EthernetXLink, EthernetTapServer.

== SI - Serial Interface ==
[https://github.com/dolphin-emu/dolphin/blob/master/Source/Core/Core/HW/SI/SI_Device.h Dolphin Emulator sources] show devices using SI. We found this devices: GBA (Game Boy Advance), CONTROLLER, KEYBOARD, STEERING, TARUKONGA. The Serial Interface use the [https://n64brew.dev/wiki/Joybus_Protocol Joybus] protocol.

== Softwares ==

This softwares can handle dol files:
* [https://github.com/Virtual-World-RE/NeoGF/tree/main/doltool doltool.py] - Virtual World RE.
* [https://github.com/sup39/GeckoLoader GeckoLoader], - JoshuaMKW, sup32.

[[Category:File format]]