wasm-emu: replace blanket store-TCI with mixed-store fallback (E35-E38)

docs/wasm-inflate-panic.md

@@ -794,3 +794,46 @@ Next useful step: dump or instrument the generated WASM for this exact TB and
 inspect the `sw a2,24(s0)` / following `lbu` fast-path sequence. The current
 node dump helper only captures early boot TBs, so late-reader TB dumping needs a
 browser/open-window trigger or a PC-filtered `wasm_dump_module` path.
+
+
+## E35-E38: TB dump and narrowed production fallback
+
+Added `?dumpstpc=LO-HI`, which dumps generated WASM modules for TBs in a PC
+window. In browser runs the dump is emitted as hex in `_scratch/browser-raw-sd.log`
+and reconstructed with `wasm2wat`.
+
+The relevant dump shows the failing region is split into small restartable TBs
+with qemu load/store slow-path helper machinery. The important isolation remains
+runtime behavior rather than static shape: interpreting the fault-path TB window
+prevents the TLB corruption; compiling it allows a valid DRAM page's TLB entry
+to flip to `TLB_MMIO`/`xlat_section=0`.
+
+Tested a firmware-independent fallback class:
+
+- compile pure store TBs;
+- keep mixed store+load/helper TBs TCI.
+
+Rationale: the bad `uzlib_uncompress` TB is a mixed memory/helper TB, and pure
+store TBs were exonerated by the earlier per-TB and whole-execution differential
+runs.
+
+Results:
+
+- `?nostoretci&storehelpertci`: 4 clean passes plus 1 post-reader close timeout,
+  with no corruption signature.
+- New default (mixed store+load/helper TBs TCI, pure store TBs compiled): 3/3
+  clean reader-open passes (`44.5s`, `44.5s`, `46.5s`).
+- Negative control `?nostoretci`: still crashes at the original
+  `0x4201e210`/`0x3FCB80xx` signature.
+
+This drops the blanket "all store TBs TCI" fallback and replaces it with the
+smallest currently validated generic rule. It is still a conservative fallback,
+not a full codegen fix: the root bug remains in compiled mixed memory/helper TBs
+corrupting the softmmu TLB arrays.
+
+New debug knobs:
+
+- `?dumpstpc=LO-HI` dumps generated WASM for TBs in a PC window.
+- `?storehelpertci` re-enables the mixed store+load/helper fallback even under
+  `?nostoretci` for A/B testing.
+- `?tlbguard=open` remains a negative probe; it did not catch the corruption.

web/app.js

@@ -504,12 +504,17 @@ async function boot(file, variant, setStatus) {
     if (params.get('tlbguard') === 'open') {
       window.xteinkEnableTlbguard = () => options._wasm_tlb_guard_enable();
     } else if (params.has('tlbguard')) options._wasm_tlb_guard_enable();
+    if (params.has('storehelpertci')) options._wasm_set_store_helper_tci();
     if (params.has('sthash')) options._wasm_set_store_tci_hash(Number(params.get('sthash')) || 1);
     if (params.has('stcmask')) options._wasm_set_store_bisect(Number(params.get('stcw')) || 0, Number(params.get('stcmask')) >>> 0, (Number(params.get('stcval')) || 0) >>> 0);
     if (params.has('stpc')) {
       const [lo, hi] = params.get('stpc').split('-').map(v => Number(v));
       options._wasm_set_store_pc_window(lo >>> 0, hi >>> 0);
     }
+    if (params.has('dumpstpc')) {
+      const [lo, hi] = params.get('dumpstpc').split('-').map(v => Number(v));
+      options._wasm_set_dump_pc_window(lo >>> 0, hi >>> 0);
+    }
     options.FS.mkdirTree('/bios');
     options.FS.mkdirTree('/var/tmp');
     options.FS.writeFile('/bios/esp32c3-rom.bin', rom);