PDP-11/45 Minimal Kernel (C + C++ starter)

Target

• PDP-11/45 (MMU-equipped)
• Test: SIMH PDP-11 emulator
• Kernel core: C
• Small C++ helpers: limited features (no exceptions, no RTTI, avoid stdlib)

What this tree provides

• Minimal boot and entry sequence (MACRO-11-style assembly)
• Vector placeholders and timer IRQ hook
• Context save/restore primitives (assembly)
• Kernel core in C: kmain, basic task structure, create_task, timer IRQ -> scheduler
• Tiny C++ helper (no exceptions, no RTTI, avoid STL)
• Linker script and Makefile with placeholders for a PDP-11 cross-toolchain
• SIMH config snippet and a README explaining next steps

Build notes

• PDP-11 cross-toolchains are uncommon; this Makefile uses placeholders:
  • AS = pdp11-as (assembler)
  • CC = pdp11-gcc or pdp11-gcc-like (C compiler)
  • LD = pdp11-ld (linker)
• If you do not have a native cross-toolchain, I can:
  • Suggest and target a specific vintage toolchain (PCC/mac or others), or
  • Produce assembly-only artifacts convertible to SIMH memory load commands.

SIMH

• Use simh pdp11 and load the produced flat binary or use SIMH load/attach commands.
• The README and simh.ini contain quick notes; I can produce a tested SIMH command sequence if you want a runnable image.

Next steps I can do after you confirm:

• Produce the files and attempt to build a SIMH-ready kernel.bin (pick a toolchain or let me pick one).
• Implement MMU initialization and a per-process mapping example for PDP-11/45.
• Implement a simple disk loader to boot from simulated RK/RL disk images in SIMH.