Reduce TLS memory requirements for KOReader sync

Split heap gate into separate free-memory (50KB) and largest-block (20KB) thresholds based on field measurements. Enable wolfSSL single-precision ECC to use fixed 256-bit arrays instead of heap-allocated fast-math bignums, reducing TLS handshake memory footprint. Reclaim ~7KB by right-sizing ESP timer task stacks and move WiFi code out of IRAM to free ~25-30KB for heap. Add memory audit landmarks for font and EPUB allocations.
2026-07-14 14:53:41 -04:00
parent 02398c8a96
commit a86a644adc
16 changed files with 200 additions and 75 deletions
@@ -12,8 +12,12 @@ OVERRIDES = f"""
 #ifndef HAVE_FFDHE_2048
 #define HAVE_FFDHE_2048
 #endif
+/* MEMFIX-PORT: 8192 handles up to RSA-4096 keys (the public-CA maximum,
+   ISRG Root X1 included) with half the per-bignum heap of 16384: with
+   WOLFSSL_SMALL_STACK each fast-math temp is FP_MAX_BITS/8 * 2 bytes on the
+   heap, and TLS cert verification allocates dozens at once. */
 #undef FP_MAX_BITS
-#define FP_MAX_BITS 16384
+#define FP_MAX_BITS 8192
 """