_ifetch_gate.nx

_ifetch_gate.nx -- gate for INSTRUCTION-FETCH translation (virtual-memory-paging-mmu completion). NO mocks. (1) FETCH TRANSLATION -- emits the ifetch test (nx_ifetch_emit) + runs it on the sovereign emu: after csrrw satp (MODE=Sv39), mret lands the PC at a VIRTUAL address 0xC0000000+cont_off; the CPU FETCHES the continuation through the page table (VA 0xC00000xx -> PA 0x800000xx) and runs it in S-mode -> "IOK". VA != PA, so "IOK" proves the fetch itself was translated. (2) TAMPER bad code-PTE -- re-emit with the code page's Valid bit cleared (0x20000006): the mret targets an unmapped virtual PC -> the FETCH walk faults -> instruction-page-fault (mcause=12) -> the M-mode handler emits "IPF". "IPF" present + "IOK" gone = the fetch genuinely walks + validates the page table on every instruction (translation is not a rubber stamp). Evidence -> knowledge/status/paging.log (IFETCHGATE row). Sovereign. license_tier: ORIGINAL