46 lines
2.1 KiB
Text
46 lines
2.1 KiB
Text
|
|
||
|
|
# DasOS Concepts
|
||
|
|
|
||
|
|
## Memory Layout
|
||
|
|
|
||
|
|
| Start | Length | Length -h | Description |
|
||
|
|
|------------|------------|-----------|--------------------------------------------------------------------------|
|
||
|
|
| 0x00000000 | 0x40000000 | 1 GB | Kernel Space. This is where the kernel and its functionality is located. |
|
||
|
|
| 0x00100000 | ??? | ??? | Kernel entry point and load target. Here the kernel will be loaded. |
|
||
|
|
| 0x20000000 | 0x20000000 | 512 MB | Kernel Heap. This memory is used for dynamic allocations in the kernel. |
|
||
|
|
| 0x40000000 | 0xC0000000 | 3 GB | User Space. This is where Artifacts are loaded and executed. |
|
||
|
|
|
||
|
|
### Kernel Heap
|
||
|
|
|
||
|
|
A simple storage allocator.
|
||
|
|
|
||
|
|
Storage of:
|
||
|
|
- Task Descriptions
|
||
|
|
- Memory Mapping Information
|
||
|
|
- Location of loaded artifacts
|
||
|
|
- ...
|
||
|
|
|
||
|
|
## Starting a Task
|
||
|
|
|
||
|
|
### Requirements
|
||
|
|
|
||
|
|
- allocate task structure
|
||
|
|
- allocate mapping directory
|
||
|
|
- fill mapping directory with
|
||
|
|
- Lower End: Copy kernel mappings
|
||
|
|
- Upper End: Copy artifact data
|
||
|
|
- allocate task stack
|
||
|
|
|
||
|
|
## Executables, Libraries and Stuff
|
||
|
|
|
||
|
|
Artifact = Executable + Library + Shared Memory
|
||
|
|
|
||
|
|
### Artifact Types
|
||
|
|
|
||
|
|
| Type | Entry Point | Description |
|
||
|
|
|------------|-------------|--------------------------------------------------------------------------------------------------------------------------------------|
|
||
|
|
| Program | _main | A program targeted at user or system administrator. Can be executed with command line arguments. Uses stdin, stdout, stderr. |
|
||
|
|
| Library | _libmain | Can be loaded by other artifacts and allows utilization of a shared set of functions. |
|
||
|
|
| Service | _svcmain | A service is a background worker that won't be terminated when its main function returns. Can be 'woken up' by an external artifact. |
|
||
|
|
| Driver | _drvinit | A driver is loaded at system start and is allowed to request and dispatch interrupts. Can be used to create a flexible OS. |
|