PRODINFO: Revamp blanking/write disallow policy. (#913)

* exo/fusee: hookup new prodinfo settings

* fusee: new scheme doesn't need FLAGS_DEFAULT

* fusee: fix c/p errors

* ams.mitm: completely revamp prodinfo backup mechanism

* ams.mitm: Implement revamped blanking/write policy

* strat: make early boot more debuggable

* exo: condense flag logic

libraries/libstratosphere/source/ams/ams_bpc.c

@@ -24,6 +24,11 @@ NX_GENERATE_SERVICE_GUARD(amsBpc);
 Result _amsBpcInitialize(void) {
     Handle h;
     Result rc = svcConnectToNamedPort(&h, "bpc:ams"); /* TODO: ams:bpc */
+    while (R_VALUE(rc) == KERNELRESULT(NotFound)) {
+        svcSleepThread(50000000ul);
+        rc = svcConnectToNamedPort(&h, "bpc:ams");
+    }
+
     if (R_SUCCEEDED(rc)) serviceCreate(&g_amsBpcSrv, h);
     return rc;
 }
@@ -44,3 +49,11 @@ Result amsBpcRebootToFatalError(void *ctx) {
         .buffers = { { ctx, 0x450 } },
     );
 }
+
+
+Result amsBpcSetInitialPayload(const void *src, size_t src_size) {
+    return serviceDispatch(&g_amsBpcSrv, 65001,
+        .buffer_attrs = { SfBufferAttr_In | SfBufferAttr_HipcMapAlias },
+        .buffers = { { src, src_size } },
+    );
+}