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Reimplement the procedure chain stacks hardware top #8

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opened 2021-07-21 20:52:22 +02:00 by numas13 · 0 comments
numas13 commented 2021-07-21 20:52:22 +02:00
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In Embox, writing to controls registers is done before writing to procedure stack pointers registers. Currently qemu-e2k have no hardware tops for the stacks and the last write to the control registers is lost after writing to PCSP. It is unknown whether this is a bug due to the lack of ISA specification for the E2K architecture. It is assumed that reimplementation of stacks hardware tops is requred for the system emulation.

  • Add PCSHTP register.
  • Implement procedure chain stack hardware top.
  • Rework read/write to the control registers.
  • Rework procedure calls.
  • Rework stack manupulation syscalls.

The minimum required size is unknown for PCSHT, but one set of CRs will be enough to solve the problem.

In Embox, [writing to controls registers](https://github.com/embox/embox/blob/ccc3fad676e21439b3a162be93ca57c3cf797949/src/arch/e2k/context_switch.S#L60-L63) is done before [writing to procedure stack pointers registers](https://github.com/embox/embox/blob/ccc3fad676e21439b3a162be93ca57c3cf797949/src/arch/e2k/context_switch.S#L72-L77). Currently qemu-e2k have no hardware tops for the stacks and the last write to the control registers is lost after writing to PCSP. It is unknown whether this is a bug due to the lack of ISA specification for the E2K architecture. It is assumed that reimplementation of stacks hardware tops is requred for the system emulation. - [ ] Add PCSHTP register. - [ ] Implement procedure chain stack hardware top. - [ ] Rework read/write to the control registers. - [ ] Rework procedure calls. - [ ] Rework stack manupulation syscalls. The minimum required size is unknown for PCSHT, but one set of CRs will be enough to solve the problem.
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a1batross was assigned by numas13 2021-07-21 20:52:22 +02:00
numas13 added this to the System Emulation project 2021-07-21 20:52:22 +02:00
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Reference: OpenE2K/qemu-e2k#8
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