BlackMark
e4390d2ba8
The pin crosses libavr's phase 6 - the renamed system surface, the named serial configs, the receiver-tolerance table, the paged SPM receipts - and every loader image comes out size-identical: the full matrix on six representative chips (the exhaustive cross product on three of them), the stock and autobaud columns untouched, the four tsb tiers back on their recorded floors at 510/526/638/836. Byte parity was not free, and the two libavr defects it surfaced were fixed there rather than absorbed here. The EEPROM write procedure's step 2 - the SPMEN spin - had landed unconditionally and cost every build six bytes for a wait a polled loader can never take; it is scoped now, and the loaders state the datasheet's own omission clause (spm_interlock::omitted, DS40002061B 8.6.3). The blocking page erase/write grew an internal wait the tiers' settle() already provides, so the tiers issue the command form and pureboot keeps its host-driven sp_spm path. What the port states rather than inherits: the stock 115200 at 16 MHz sits +2.1 % past the receiver-tolerance table libavr now holds rates to, so the hardware links say .allow_baud_error = true - the same 2.5 % envelope pureboot_baud_feasible() has always enforced, proven on silicon across the fleet. rx_ready() reads readable() now. Alongside the pin: rule 33's ASCII sweep over every source (docs keep their typography), rule 34's InsertBraces in .clang-format with the tree reformatted, std::array over the simavr runners' raw buffers, and the stale Studio size in ide/README.md replaced by the claim its check-flags gate actually holds. Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>
79 lines
3.9 KiB
Markdown
79 lines
3.9 KiB
Markdown
# Atmel Studio
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`master` carries `bootloader.atsln`, so this branch does too: `ide/bootloader.atsln`
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builds the loaders from the same sources Ninja does, to a **byte-identical
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`.text`** — the stock 328P pureboot deployment and the `tsb_asm` tier in its
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512-byte section (`check-flags.py` below is what holds the flag sets equal, so
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the sizes are Ninja's own). CMake remains the build system; the solution is
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here so the port opens in Studio as its predecessor did.
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## The two projects, and why two
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pureboot is a chip × backend × clock × baud matrix — `pureboot_add_loader()`
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resolves a deployment into compile definitions — and a `.cppproj` is one binary
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at one set of flags, so a project can only ever be one point of it. `pureboot`
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is that point: the stock 328P deployment, USART0 at 115200 on a 16 MHz crystal,
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an 8-second activation window. `tsb_asm` is the TinySafeBoot tier that occupies
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the same 512-byte section `master`'s `tsb` project targeted.
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The other three tsb tiers (`tsb_pure`, `tsb_tricks`, `tsb_policy`) are not here.
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They differ from `tsb_asm` in their source file, their section size, and — for
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`tsb_policy` — two loop flags; nothing about that is a Studio concern, and what
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they exist to demonstrate is a size gradient only the CMake size tests measure.
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Adding one is a copy of `tsb_asm/tsb_asm.cppproj` in its own directory, with its
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name, its GUID, its source path and its `--section-start` changed (`0x7c00` for
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the 1 KiB tiers), plus four lines in the solution.
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`avrdevice` is a project property, so each project gets its own directory:
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Studio builds into `<project dir>/<Configuration>` whatever `OutputDirectory`
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says, and two projects sharing a directory would share one object file.
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## Debug keeps `-Os`
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Both configurations compile at `-Os`; Debug adds only `-gdwarf-4`. The `.text`
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is therefore identical in both, which is the point — a loader's section is a
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**correctness** bound and not a budget. `-Og` builds this same source to 590 B,
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and linking it at `--section-start=.text=0x7e00` on a 32 KiB part puts 78 bytes
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past flash end **without a diagnostic**: `rcall`/`rjmp` targets there wrap
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modulo flash size, so the image dies right after activation. A debug
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configuration that silently produces that is worse than none, and DWARF costs no
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flash, so the optimisation level stays where correctness needs it.
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## What Studio needs from the machine
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libavr from the **submodule**, found at
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`$(MSBuildProjectDirectory)\..\..\libavr\include` — correct by construction, and
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anchored to the project because a plain relative path resolves against the
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generated makefile's directory (the configuration's output directory), not the
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project's. There is no `LIBAVR_ROOT` escape hatch: a variable exported in a
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shell is invisible to Studio launched from the Start menu, and the failure reads
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as a missing `libavr/libavr.hpp` — which is what the submodule answers.
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A GCC 16.1 toolchain registered as flavour `avr-g++-16.1.0`, nothing older
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reaching `-std=c++26`.
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## Generating and gating
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One generated file is required before a project will load at all, and one command
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per project checks the flags have not drifted (both from libavr's
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`tools/atmelstudio/`):
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```sh
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for name in pureboot tsb_asm; do
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python libavr/tools/atmelstudio/componentinfo.py \
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"ide/$name/$name.componentinfo.xml" --device ATmega328P
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python libavr/tools/atmelstudio/check-flags.py \
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--solution ide/bootloader.atsln --project "$name" --target "$name" \
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--compile-commands build/atmega328p-generated/compile_commands.json \
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--log "build/as-$name.log"
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done
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```
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`--project` because one reference describes one binary; `--target` because
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`pureboot.cpp` is compiled by every point of the size matrix and the flags
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differ per point, so the basename alone does not name a reference. Release is
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what the gate compares — the presets define no debug build, and Debug differs
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from Release only in `-gdwarf-4`.
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Legacy (the yazoalfa-era submodules) stays on `master`.
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