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

config_templates/exosphere.ini

@@ -0,0 +1,45 @@
+# Key: debugmode, default: 1.
+#  Desc: Controls whether kernel is debug mode.
+#   Disabling this may break Atmosphere's debugger in a future release.
+
+# Key: debugmode_user, default: 0.
+#  Desc: Controls whether userland is debug mode.
+
+# Key: disable_user_exception_handlers, default: 0.
+#  Desc: Controls whether user exception handlers are executed on error.
+#  NOTE: This will cause atmosphere to not fail gracefully.
+#   Support may not be provided to users tho disable these.
+#   If you do not know what you are doing, leave them on.
+
+# Key: enable_user_pmu_access, default: 0.
+#  Desc: Controls whether userland has access to the PMU registers.
+#  NOTE: It is unknown what effects this has on official code.
+
+# Key: blank_prodinfo_sysmmc, default: 0.
+#  Desc: Controls whether PRODINFO should be blanked in sysmmc.
+#   This will cause the system to see dummied out keys and
+#   serial number information.
+#  NOTE: This is not known to be safe, as data may be
+#   cached elsewhere in the system. Usage is not encouraged.
+
+# Key: blank_prodinfo_emummc, default: 0.
+#  Desc: Controls whether PRODINFO should be blanked in emummc.
+#  NOTE: This is not known to be safe, as data may be
+#   cached elsewhere in the system. Usage is not encouraged.
+
+# Key: allow_writing_to_cal_sysmmc, default: 0.
+#  Desc: Controls whether PRODINFO can be written by homebrew in sysmmc.
+#  NOTE: Usage of this setting is strongly discouraged without
+#    a safe backup elsewhere. Turning this on will also cause Atmosphere
+#    to ensure a safe backup of calibration data is stored in unused
+#    mmc space, encrypted to prevent detection. This backup can be used
+#    to prevent unrecoverable edits in emergencies.
+
+[exosphere]
+debugmode=1
+debugmode_user=0
+disable_user_exception_handlers=0
+enable_user_pmu_access=0
+blank_prodinfo_sysmmc=0
+blank_prodinfo_emummc=0
+allow_writing_to_cal_sysmmc=0