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Replace placeholder content in doc/compat/, doc/lvglh/, and doc/toolchain/ with comprehensive documentation derived from the source files. - compat: document Wasuro WASM VM compatibility shims - lvglh: document LVGL v9.2.2 configuration, fonts, and patches - toolchain: document all 13 build pipeline scripts
48 lines
2.2 KiB
Markdown
48 lines
2.2 KiB
Markdown
# compile_link.sh
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Links all object files and libraries into the final kernel binary.
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## Overview
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`compile_link.sh` collects every `.o` object file in `lib/`, locates `libgcc` for i386, and invokes the GNU linker (`ld`) to produce `bin/kernel.bin`. The linker script `toolchain/linker.script` controls the memory layout of the resulting binary.
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## Prerequisites
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- `ld` (GNU linker) and `gcc` must be available.
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- All object files must have been produced by prior build steps (`compile_stub.sh`, `compile_sources.sh`).
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- `lib/liblvgl.a` must exist (produced by `compile_lvgl.sh`).
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- `toolchain/linker.script` must exist.
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- The `bin/` output directory must exist.
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## Inputs
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| Source | Description |
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|--------|-------------|
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| `lib/*.o` | All ELF object files (boot stub, Pascal units, splash screen, etc.). |
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| `lib/liblvgl.a` | Static LVGL library archive. |
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| `libgcc` (system) | GCC runtime support library for i386, located via `gcc -m32 -print-libgcc-file-name`. |
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| `toolchain/linker.script` | Linker script defining section layout and entry point. |
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## Outputs
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| File | Description |
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|------|-------------|
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| `bin/kernel.bin` | The final linked, stripped kernel binary. |
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## Behavior
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1. Collects all `.o` files from `lib/`, excluding `lib/stub.o` from the general list.
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2. Prepends `lib/stub.o` to the front of the object list so the boot entry point is linked first.
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3. Locates `libgcc` for the 32-bit target using `gcc -m32 -print-libgcc-file-name`.
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4. Invokes `ld` with the following flags:
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- `-m elf_i386` -- Target i386 ELF format.
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- `-s` -- Strip all symbol information.
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- `--gc-sections` -- Remove unused sections (works with FPC's `-CX -XXs` smart-linking).
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- `-T toolchain/linker.script` -- Use the project linker script.
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- `--start-group` / `--end-group` -- Wraps `liblvgl.a` and `libgcc` to resolve circular references between them.
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## Notes
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- `stub.o` must be first in the link order because it contains the multiboot header and the initial entry point that GRUB transfers control to.
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- The `--start-group` / `--end-group` construct allows the linker to iterate over `liblvgl.a` and `libgcc` multiple times to resolve all symbols, which is necessary when C library objects have mutual dependencies.
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