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add memory lib + maps

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Frater 2026-02-07 16:03:29 +01:00
commit 4b62e01e82
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doc/MEMORY_MAP.md
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@ -8,18 +8,20 @@ The processor starts in Real Mode, addressing 1 MB of memory.
| Physical Start | Physical End | Size | Description | Segment | Source File |
| :--- | :--- | :--- | :--- | :--- | :--- |
| **`0x00000`** | **`0x003FF`** | 1 KB | **IVT** (Interrupt Vector Table) | `0x0000` | `boot.asm` / `generic.asm` |
| **`0x00400`** | **`0x004FF`** | 256 B | **BDA** (BIOS Data Area) Standard | `0x0040` | `common/bda.asm` |
| **`0x00500`** | **`0x005FF`** | ~256 B | **Custom BDA** (Driver Data) | `0x0050` | `common/bda.asm` |
| ... | ... | ... | *Free / Reserved* | | |
| **`0x08000`** | **`0x09FFF`** | 8 KB | **Stack Bottom** | `0x0800` | `boot.asm` |
| **`0x0A000`** | **`0x0AFFF`** | ~4 KB | **GUI RAM** (Widget Allocation) | `0x0A00` | `gui/lib.asm` |
| **`0x0B000`** | **`0x17FFE`** | ~52 KB | **Stack Top** (Grows downwards) | `0x0800` | `boot.asm` |
| ... | ... | ... | *Conventional RAM Free* | | |
| **`0xB8000`** | **`0xBFFFF`** | 32 KB | **VRAM** (CGA / MCGA) | `0xB800` | `drivers/gfx_cgam.asm` |
| **`0xC0000`** | **`0xDFFFF`** | 128 KB | **Option ROMs** (e.g., VGA BIOS) | `0xC000` | `boot.asm` |
| ... | ... | ... | *System Reserved* | | |
| **`0xF0000`** | **`0xFFFFF`** | 64 KB | **System BIOS ROM** (Code) | `0xF000` | `boot.asm` |
| **`0x00000`** | **`0x003FF`** | 1 KB | **IVT** (Interrupt Vector Table) | `0x0000` | `memory.asm` |
| **`0x00400`** | **`0x004FF`** | 256 B | **BDA** (BIOS Data Area) Standard | `0x0040` | `memory.asm` |
| **`0x00500`** | **`0x005FF`** | ~256 B | **Custom BDA** (Driver Data) | `0x0050` | `memory.asm` |
| **`0x00600`** | **`0x07FFF`** | 30.5 KB | **Free** (Low Memory) | | |
| **`0x08000`** | **`0x17FFF`** | 64 KB | **Stack** (Grows downwards) | `0x0800` | `memory.asm` |
| **`0x18000`** | **`0x18FFF`** | ~4 KB | **GUI RAM** (Widget Allocation) | `0x0A00` | `gui/lib.asm` |
| **`0x19000`** | **`0x9FBFF`** | 539 KB | **Free** (Conventional RAM) | | |
| **`0x9FC00`** | **`0x9FFFF`** | 1 KB | **EBDA** (Extended BIOS Data Area) | `0x9FC0` | `memory.asm` |
| **`0xA0000`** | **`0xAFFFF`** | 64 KB | **VGA RAM** (Graphics Modes) | `0xA000` | `Hardware` |
| **`0xB0000`** | **`0xB7FFF`** | 32 KB | **MDA RAM** (Monochrome Text) | `0xB000` | `Hardware` |
| **`0xB8000`** | **`0xBFFFF`** | 32 KB | **VRAM** (CGA / MCGA) | `0xB800` | `memory.asm` |
| **`0xC0000`** | **`0xDFFFF`** | 128 KB | **Option ROMs** (e.g., VGA BIOS) | `0xC000` | `memory.asm` |
| **`0xE0000`** | **`0xEFFFF`** | 64 KB | **System Reserved** (BIOS Extension) | `0xE000` | `Hardware` |
| **`0xF0000`** | **`0xFFFFF`** | 64 KB | **System BIOS ROM** (Code) | `0xF000` | `memory.asm` |
### Detailed Zones
@ -50,6 +52,10 @@ The project separates the standard IBM BDA from its own variables to avoid confl
* **Even Lines (0, 2, 4...)**: Offset `0x0000` - `0x1F3F` (Bank 0).
* **Odd Lines (1, 3, 5...)**: Offset `0x2000` - `0x3F3F` (Bank 1).
#### VGA RAM & System Reserved
* **VGA RAM (`0xA0000`)**: Standard 64 KB memory window for VGA graphics modes. Although this project primarily uses the CGA memory at `0xB8000`, this area is physically present when the VGA hardware is emulated.
* **System Reserved (`0xE0000`)**: Reserved memory area, typically used for motherboard BIOS extensions or specific hardware mapping.
#### ROM
* **Option ROMs (`0xC0000`)**: Scanned by `setup_load_rom` to initialize the VGA BIOS.
* **System ROM (`0xF0000`)**: Contains the compiled binary code. The Reset Vector is at `0xFFFF0`.
@ -64,18 +70,20 @@ Le processeur démarre en mode réel, adressant 1 Mo de mémoire.
| Adresse Physique (Début) | Adresse Physique (Fin) | Taille | Description | Segment | Fichier Source |
| :--- | :--- | :--- | :--- | :--- | :--- |
| **`0x00000`** | **`0x003FF`** | 1 Ko | **IVT** (Interrupt Vector Table) | `0x0000` | `boot.asm` / `generic.asm` |
| **`0x00400`** | **`0x004FF`** | 256 o | **BDA** (BIOS Data Area) Standard | `0x0040` | `common/bda.asm` |
| **`0x00500`** | **`0x005FF`** | ~256 o | **Custom BDA** (Données Drivers) | `0x0050` | `common/bda.asm` |
| ... | ... | ... | *Mémoire Libre / Réservée* | | |
| **`0x08000`** | **`0x09FFF`** | 8 Ko | **Bas de la Pile** (Stack Bottom) | `0x0800` | `boot.asm` |
| **`0x0A000`** | **`0x0AFFF`** | ~4 Ko | **GUI RAM** (Allocation Widgets) | `0x0A00` | `gui/lib.asm` |
| **`0x0B000`** | **`0x17FFE`** | ~52 Ko | **Haut de la Pile** (Stack Top) | `0x0800` | `boot.asm` |
| ... | ... | ... | *RAM Conventionnelle Libre* | | |
| **`0xB8000`** | **`0xBFFFF`** | 32 Ko | **VRAM** (CGA / MCGA) | `0xB800` | `drivers/gfx_cgam.asm` |
| **`0xC0000`** | **`0xDFFFF`** | 128 Ko | **Option ROMs** (ex: VGA BIOS) | `0xC000` | `boot.asm` |
| ... | ... | ... | *Réservé Système* | | |
| **`0xF0000`** | **`0xFFFFF`** | 64 Ko | **System BIOS ROM** (Code) | `0xF000` | `boot.asm` |
| **`0x00000`** | **`0x003FF`** | 1 Ko | **IVT** (Interrupt Vector Table) | `0x0000` | `memory.asm` |
| **`0x00400`** | **`0x004FF`** | 256 o | **BDA** (BIOS Data Area) Standard | `0x0040` | `memory.asm` |
| **`0x00500`** | **`0x005FF`** | ~256 o | **Custom BDA** (Données Drivers) | `0x0050` | `memory.asm` |
| **`0x00600`** | **`0x07FFF`** | 30.5 Ko | **Libre** (Mémoire Basse) | | |
| **`0x08000`** | **`0x17FFF`** | 64 KB | **Stack** (Grows downwards) | `0x0800` | `memory.asm` |
| **`0x18000`** | **`0x18FFF`** | ~4 KB | **GUI RAM** (Widget Allocation) | `0x0A00` | `gui/lib.asm` |
| **`0x19000`** | **`0x9FBFF`** | 539 Ko | **Libre** (RAM Conventionnelle) | | |
| **`0x9FC00`** | **`0x9FFFF`** | 1 Ko | **EBDA** (Extended BIOS Data Area) | `0x9FC0` | `memory.asm` |
| **`0xA0000`** | **`0xAFFFF`** | 64 Ko | **VGA RAM** (Modes Graphiques) | `0xA000` | `Matériel` |
| **`0xB0000`** | **`0xB7FFF`** | 32 Ko | **MDA RAM** (Texte Monochrome) | `0xB000` | `Matériel` |
| **`0xB8000`** | **`0xBFFFF`** | 32 Ko | **VRAM** (CGA / MCGA) | `0xB800` | `memory.asm` |
| **`0xC0000`** | **`0xDFFFF`** | 128 Ko | **Option ROMs** (ex: VGA BIOS) | `0xC000` | `memory.asm` |
| **`0xE0000`** | **`0xEFFFF`** | 64 Ko | **Réservé Système** (Extension BIOS) | `0xE000` | `Matériel` |
| **`0xF0000`** | **`0xFFFFF`** | 64 Ko | **System BIOS ROM** (Code) | `0xF000` | `memory.asm` |
### Détails des Zones
@ -106,6 +114,10 @@ Le projet sépare la BDA standard IBM de ses propres variables pour éviter les
* **Lignes Paires (0, 2, 4...)** : Offset `0x0000` à `0x1F3F` (Bank 0).
* **Lignes Impaires (1, 3, 5...)** : Offset `0x2000` à `0x3F3F` (Bank 1).
#### VGA RAM & Réservé Système
* **VGA RAM (`0xA0000`)** : Fenêtre mémoire standard de 64 Ko pour les modes graphiques VGA. Bien que ce projet utilise principalement la mémoire CGA à `0xB8000`, cette zone est physiquement présente lorsque le matériel VGA est émulé.
* **Réservé Système (`0xE0000`)** : Zone mémoire réservée, typiquement utilisée pour les extensions du BIOS de la carte mère ou le mappage de matériel spécifique.
#### ROM
* **Option ROMs (`0xC0000`)** : Espace scanné par `setup_load_rom` pour initialiser le BIOS VGA.
* **System ROM (`0xF0000`)** : Contient le code binaire compilé. Le Vecteur de Reset est situé à `0xFFFF0`.