thejayman77
ec82764bef
RTL (GS rasterizer, EE core stub, platform bridge, LPDDR4B path), sim regression (272 TBs), docs, and tooling. Copyrighted PS2 content (BIOS, game code, GS dumps, and all dump-derived textures/traces) is excluded via .gitignore and stays local. Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>
47 lines
1.1 KiB
Markdown
47 lines
1.1 KiB
Markdown
# Decision 0002: BIOS Policy
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Status: `Locked`
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## Context
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The project needed a firmware strategy that balanced authenticity with
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bring-up practicality.
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Main approaches considered:
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- real BIOS only,
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- HLE-only BIOS behavior,
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- real BIOS with narrowly-scoped debug stubs.
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## Options considered
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1. Real BIOS only.
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2. HLE-only BIOS strategy.
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3. Real BIOS plus narrow debug stubs.
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## Decision
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Adopt `real BIOS plus narrow debug stubs`.
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Policy details:
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- Real user-supplied BIOS images remain the primary firmware path.
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- Debug stubs are allowed only where they materially shorten early bring-up.
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- Stubs must be narrow, explicit, and temporary.
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Every stub must be tracked in a decision record or equivalent design note with:
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- owner,
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- purpose,
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- scope boundary,
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- removal condition.
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## Consequences
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- The project stays anchored to real PS2 boot behavior.
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- Early bring-up may proceed without waiting for every subsystem to be complete.
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- There is a maintenance cost: stub behavior must not silently become the
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architecture.
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- The repository must never include Sony BIOS images.
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- The stub-module plan must call out which stubs are in play for each phase.
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