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2407e662a9
- rtl/w11a - pdp11.vhd: add cpustat_type in_vecflow - pdp11_sequencer.vhd: BUGFIX: get correct PS after vector push abort - tools - tcode/cpu_details.mac: add test A3.5 - tcode/cpu_mmu.mac: add test C2.5, C2.6, C2.7 - xxdp/ekbee1_patch_1170.scmd: fix test 122 - xxdp/ekbee1_patch_w11a.tcl: fix test 122
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Known differences between w11a and KB11-C (11/70)
MMR0 abort flags are set when stack limit abort done
Let's assume a case where two aborts are present:
- the MMU rejects the access, e.g. because the page is non-resident
- the access is a kernel stack write and violates the stack limit
Both checks run in parallel in hardware. The MMU logic uses the access control field and the page length field to check whether access is allowed. And the effective address is compared with the stack limit.
In the KB11-C processor, the MMR0 abort bits are not set in case of a red
zone stack abort. The case described above leads to a vector 4, as it should
be, and does not set an abort bit in MMR0.
The w11 does not implement this suppression, the MMU logic and the stack limit
check logic are independent. The case described above leads to a vector 4,
but also sets an abort bit in MMR0.
The ekbee1 diagnostic tests this behavior in test 122. This test is
modified when executed on w11
(see patch).