45 lines
2.1 KiB
Text
45 lines
2.1 KiB
Text
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# DasOS Concepts
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## Memory Layout
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| Start | Length | Length -h | Description |
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|------------|------------|-----------|--------------------------------------------------------------------------|
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| 0x00000000 | 0x40000000 | 1 GB | Kernel Space. This is where the kernel and its functionality is located. |
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| 0x00100000 | ??? | ??? | Kernel entry point and load target. Here the kernel will be loaded. |
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| 0x20000000 | 0x20000000 | 512 MB | Kernel Heap. This memory is used for dynamic allocations in the kernel. |
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| 0x40000000 | 0xC0000000 | 3 GB | User Space. This is where Artifacts are loaded and executed. |
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### Kernel Heap
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A simple storage allocator.
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Storage of:
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- Task Descriptions
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- Memory Mapping Information
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- Location of loaded artifacts
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- ...
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## Starting a Task
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### Requirements
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- allocate task structure
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- allocate mapping directory
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- fill mapping directory with
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- Lower End: Copy kernel mappings
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- Upper End: Copy artifact data
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- allocate task stack
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## Executables, Libraries and Stuff
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Artifact = Executable + Library + Shared Memory
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### Artifact Types
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| Type | Entry Point | Description |
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|------------|-------------|--------------------------------------------------------------------------------------------------------------------------------------|
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| Program | _main | A program targeted at user or system administrator. Can be executed with command line arguments. Uses stdin, stdout, stderr. |
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| Library | _libmain | Can be loaded by other artifacts and allows utilization of a shared set of functions. |
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| 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. |
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| 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. |
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