feat: bring SolidSyslog into the build, nothing wired yet

.github/workflows/ci.yml

@@ -4,7 +4,6 @@ on:
   push:
     branches: [ main ]
   pull_request:
-    branches: [ main ]
 
 permissions:
   contents: read

CMakeLists.txt

@@ -33,6 +33,19 @@ endif()
 set(FREERTOS_PORT_DIR "${FREERTOS_KERNEL_PATH}/portable/GCC/ARM_CM3")
 set(LWIP_CONTRIB_FREERTOS_DIR "${LWIP_DIR}/contrib/ports/freertos")
 
+# --- SolidSyslog ---------------------------------------------------------------
+# Naming the platforms is the whole of the selection; anything unnamed is off.
+# https://docs.cososo.co.uk/solid-syslog/getting-started/#path-a--cmake-consumer
+# Pinned to a commit until there is a release tag to pin to.
+set(SOLIDSYSLOG_PLATFORMS "LwipRaw" CACHE STRING "" FORCE)
+
+include(FetchContent)
+FetchContent_Declare(SolidSyslog
+    GIT_REPOSITORY https://github.com/cososo-ltd/solid-syslog.git
+    GIT_TAG        a8d39793fc40a40987268bccccefbdc44f26f0b8
+)
+FetchContent_MakeAvailable(SolidSyslog)
+
 # --- stage FatFs so ff.h's `#include "ffconf.h"` resolves to our integrator config
 # GCC's "" lookup checks the including file's own directory first, so colocating
 # the upstream ff.c/ff.h/diskio.h with our ffconf.h is how our config wins.
@@ -148,7 +161,7 @@ target_include_directories(baseline PRIVATE
 # library, or context struct sizes diverge between consumer and library.
 target_compile_definitions(baseline PRIVATE MBEDTLS_USER_CONFIG_FILE=${MBEDTLS_USER_CONFIG_HEADER})
 
-target_link_libraries(baseline PRIVATE mbedtls mbedx509 mbedcrypto)
+target_link_libraries(baseline PRIVATE mbedtls mbedx509 mbedcrypto SolidSyslog SolidSyslog::LwipRaw)
 
 target_link_options(baseline PRIVATE
     -mcpu=cortex-m3 -mthumb

README.md

@@ -10,16 +10,26 @@ It builds on a baseline that simulates the sort of device you might be adding th
 measures itself: see [docs/baseline.md](docs/baseline.md) for what the baseline is, how the
 figures are made, and how to run it.
 
-## This stage — Baseline
+## This stage — Linked
 
-The device before any of this: networking up, a filesystem mounted, and a mutual-TLS session held
-to its broker. Two application tasks sit idle, ready to be occupied.
+SolidSyslog is linked into the application without any of it being called. The stage is broken out
+for clarity: it separates getting the build to accept the library from getting the device to use
+it, so anything that goes wrong here is a build problem and nothing else.
 
-Nothing is logged and nothing is sent. This is the thing every later figure is measured against.
+Three lines carry it. `FetchContent` nests the library under this build. `SOLIDSYSLOG_PLATFORMS`
+names the platforms rather than letting the library infer them from the environment — lwIP alone,
+because nothing at this stage reaches any other pack. Then one link line, for the core library and
+that pack.
+
+`--gc-sections` discards what nothing calls, so a platform pack that is linked but unused does not
+reach the image.
+
+For now you need only the core and a network platform. The library has no release tag yet, so the
+pin is a commit.
 
 <!-- STAGE-COST:START (generated by scripts/gen-cost-table.py — do not edit by hand) -->
 
-This is the baseline itself: Flash 350,308 B, RAM 111,192 B.
+**Cost above baseline: Flash +0 B, RAM +0 B.**
 
 <!-- STAGE-COST:END -->
 
@@ -33,6 +43,7 @@ committed as [`run-report.md`](run-report.md), and rewritten by every stage.
 | Stage | What it gives you | Flash | RAM |
 |---|---|---|---|
 | Baseline | a device that already networks, stores, and holds an mTLS session — before any syslog | — | — |
+| Linked | the core library and lwIP raw-mode networking, linked but not yet called | +0 | +0 |
 
 *Deltas are bytes above the baseline, which is itself Flash 350,308 B, RAM 111,192 B.*
 
@@ -45,3 +56,7 @@ This example's own code is [0BSD](LICENSE) — completely open, no conditions.
 Third-party code keeps its own license: the vendored Arm SMSC9220 driver (`app/net/smsc9220/`) is
 Apache-2.0 (see its `LICENSE`). FreeRTOS, lwIP, mbedTLS, and FatFs are consumed from the build
 container under their own upstream licenses and are not redistributed here.
+
+SolidSyslog is fetched at build time and is likewise not redistributed here. It is offered under
+three alternative licenses, which its own
+[LICENSE.md](https://github.com/cososo-ltd/solid-syslog/blob/main/LICENSE.md) sets out.

measurements/linked.csv

@@ -4,8 +4,8 @@ flash_text,349992
 flash_data,316
 static_bss,110876
 heap_used,4440
-mbedtls_peak,21324
-mbedtls_free,11444
+mbedtls_peak,21280
+mbedtls_free,11488
 lwip_mem_free,7576
 lwip_pbufs_free,13
 stack_log,120

measurements/stages.tsv

@@ -8,5 +8,6 @@
 # out and says so rather than publishing a blank row.
 #
 # Slugs, not numbers: a stage inserted mid-history would renumber every file
-# after it, and this history has already had one inserted.
+# after it.
 Baseline	Baseline	a device that already networks, stores, and holds an mTLS session — before any syslog
+linked	Linked	the core library and lwIP raw-mode networking, linked but not yet called

run-report.md

@@ -1,4 +1,4 @@
-# solid-syslog-example — run (Baseline)
+# solid-syslog-example — run (linked)
 
 ## Device (self-measured)
 
@@ -13,10 +13,10 @@
 [report] flash_data,316,316,0
 [report] static_bss,110876,110876,0
 [report] heap_used,4440,4440,0
-[report] mbedtls_peak,21340,21332,8
-[report] mbedtls_free,11428,11436,-8
+[report] mbedtls_peak,21232,21332,-100
+[report] mbedtls_free,11536,11436,100
 [report] lwip_mem_free,7576,7576,0
-[report] lwip_pbufs_free,14,14,0
+[report] lwip_pbufs_free,13,14,-1
 [report] stack_log,120,120,0
 [report] stack_service,52,52,0
 [report] stack_harness,2840,2840,0
@@ -49,17 +49,17 @@
 (nothing — this device sends no records yet)
 ```
 
-## Self-check (vs measurements/Baseline.csv)
+## Self-check (vs measurements/linked.csv)
 
 ```text
   OK    flash_text: 349992 (expected 349992, Δ0)
   OK    flash_data: 316 (expected 316, Δ0)
   OK    static_bss: 110876 (expected 110876, Δ0)
   OK    heap_used: 4440 (expected 4440, Δ0)
-  OK    mbedtls_peak: 21340 (expected 21332, Δ8)
-  OK    mbedtls_free: 11428 (expected 11436, Δ8)
+  OK    mbedtls_peak: 21232 (expected 21280, Δ48)
+  OK    mbedtls_free: 11536 (expected 11488, Δ48)
   OK    lwip_mem_free: 7576 (expected 7576, Δ0)
-  OK    lwip_pbufs_free: 14 (expected 14, Δ0)
+  OK    lwip_pbufs_free: 13 (expected 13, Δ0)
   OK    stack_log: 120 (expected 120, Δ0)
   OK    stack_service: 52 (expected 52, Δ0)
   OK    stack_harness: 2840 (expected 2840, Δ0)