# Rust often needs a bit of an extra main task stack size compared to C (the default is 3K) # You might have to increase this further if you allocate large stack variables in the main task. # Bumped for the TLS handshake (Spike 6): mbedtls runs on the calling task and # wants several KB of stack on top of the app's own usage. 12 KB ran the editor # AND a full TLS-on-main handshake on hardware — the last-known-good value for # this shared stack. # # Spike 7 briefly bumped this to 96 KB because libgit2's push chain is far deeper # (~67 KB measured for a trivial config write: nearly every function puts a 4 KB # `char path[GIT_PATH_MAX]` on the stack and init→config→FATFS→wear-leveling # nests ~10 deep). But this sdkconfig is SHARED with the editor build, so that # forced the editor to over-reserve ~80 KB for nothing. Git now runs on its own # large-stack thread instead (git_push.rs — GIT_STACK via # std::thread::Builder::stack_size), so this drops back to the Spike-6 value. # (The "time() only works on the main task" theory was a misdiagnosis: that # iteration ran git on a std::thread with the DEFAULT 4 KB stack and just # overflowed sooner — it was always stack depth, never thread-vs-main.) CONFIG_ESP_MAIN_TASK_STACK_SIZE=12288 # Increase a bit these stack sizes as they are also a bit too small by default CONFIG_ESP_SYSTEM_EVENT_TASK_STACK_SIZE=4096 CONFIG_FREERTOS_IDLE_TASK_STACKSIZE=4096 # You might have to increase this further if you spawn your own Rust threads # that allocate large stack variables; or better yet - use # `std::thread::Builder::new().stack_size(XXX)` for spawning CONFIG_PTHREAD_TASK_STACK_SIZE_DEFAULT=4096 # FatFS long filenames (Spike 3 — SD). Default is 8.3-only, which rejects the # persistence module's atomic-save temp name (`notes.md.tmp` has two dots). # LFN on the heap keeps the working buffer off the (small) task stack. CONFIG_FATFS_LFN_HEAP=y # PSRAM (Spike 7 — the git working set needs it; the docs memory plan budgets # ~1.5 MB PSRAM for pack/delta work, and the rope buffer lives there too). This # board is an ESP32-S3-WROOM-1-N16R8 → 8 MB *octal* PSRAM, so OCT mode is # required (quad would fail to init). USE_MALLOC adds PSRAM to the heap # allocator, so large allocations (Box, Rope, libgit2 buffers) land there # instead of the ~339 KB internal DRAM Spike 6 measured. Octal PSRAM occupies # GPIO 33–37; the EPD/SD pins (4–13) deliberately avoid that range, so no wiring # conflict. Speed left at the 40 MHz default (safe first-enable; 80 MHz needs # matching flash-freq config and is a later tuning step). CONFIG_SPIRAM=y CONFIG_SPIRAM_MODE_OCT=y CONFIG_SPIRAM_USE_MALLOC=y # FatFS fast seek (sync-latency root cause, 2026-07-12). Without it, lseek # resolves by walking the file's FAT cluster chain over SPI — forward from the # current position, from the CHAIN HEAD on any backward seek. sd_bench measured # ~190 ms per long seek into the 263 MB packfile (5.8 ms at offset 0), and # libgit2 pays ~8 such seeks per loose-object write via p_mmap's lseek+read → # the ~1.5 s/object commit cost (docs/tradeoff-curves/sync-commit-staging.md). # Fast seek builds an in-memory cluster-link map (CLMT) per READ-mode file, # making lseek O(1); write-mode files transparently fall back to the walk. The # buffer is per-open-file, 4 B × size: 256 words = 1 KB, covering ~127 fragments # (the default 64 covers ~31 — a freshly-provisioned pack is near-contiguous, # but don't let card aging silently disable the fix; vfs_fat falls back to slow # seeks when the map doesn't fit). CONFIG_FATFS_USE_FASTSEEK=y CONFIG_FATFS_FAST_SEEK_BUFFER_SIZE=256 # Silence the legacy-I2C boot warning. esp-idf-hal's i2c.rs is always compiled # and binds the old `driver/i2c.h` API, so the legacy driver's TU (and its # `__attribute__((constructor))` deprecation warning) gets linked into every # image — even though Typoena uses no I2C at all (EPD/SD are SPI, keyboard is # USB). This flag wraps that constructor out. Safe here: we link neither the # new i2c_master driver nor call the old one, so the conflict-abort check it # also removes can never fire. CONFIG_I2C_SKIP_LEGACY_CONFLICT_CHECK=y # TLS trust store (Spike 6 — Wi-Fi + TLS, the gate for Spike 7 git push). # The certificate bundle backs esp_crt_bundle_attach so an HTTPS GET to # api.github.com validates against real roots. FULL rather than the common # subset so a less common CA in the chain can't surprise us on the bench. CONFIG_MBEDTLS_CERTIFICATE_BUNDLE=y CONFIG_MBEDTLS_CERTIFICATE_BUNDLE_DEFAULT_FULL=y