RISC-V CoPro BBC BASIC memory map

[gerph]

I've created a diagram showing the memory map as used for the RISC-V CoPro's BBC BASIC, from https://github.com/hoglet67/PiTubeDirect/wiki/RISC-V-Co-Pro-Notes#rvbasic-memory-map using my 'memory layout' tool.

The output looks like this.

This is using the memory layout tool I wrote - https://pypi.org/project/memory-layout/

Generating the output

1. Create a file called riscv-bbcbasic.mld:

%YAML 1.1
---
# BBC BASIC for RISC-V memory map, from https://github.com/hoglet67/PiTubeDirect/wiki/RISC-V-Co-Pro-Notes#rvbasic-memory-map
defaults:
  # Layout options
  unit_size: 0x10000
  unit_height: 0.3
  min_height: 0.3
  max_height: 1.0
  discontinuity_height: 2
  region_width: 3.25

  # Presentation options
  background: "#FFF"
  fill: "#FFF"
  outline: "#487748"
  outline_width: 2pt
  colour: "#487748"
  position: l

  # Address labels
  address_format: acorn

layout:

  0x00000000:
    size: 0x10000
    labels:
      "l": Basic String Buffer (64KB)

  0x00010000:
    size: 0xC00
    labels:
      "l": Basic Miscellaneous Buffers (3KB)

  0x00010C00:
    size: 0x76F400
    labels:
      "er,ib": "&00010C00 = default PAGE"

  0x00780000:
    size: 0x780000
    labels:
      "er,ib": "&00780000 = default HIMEM"
      "er,it": "&00F00000 = maximum HIMEM"
      "b": "BASIC Program/Workspace"
    junction_low: ticks

  0x00F00000:
    size: 0x40000
    labels:
      "l": C language heap (256KB, grows upwards)

  0x00F40000:
    size: 0x40000
    labels:
      "l": RISC-V stack (256KB, grows downwards)

  0x00F80000:
    size: 0x40000
    labels:
      "l": BBC Basic (256KB, 140KB used)

  0x00FC0000:
    size: 0x3FFE0
    labels:
      "l": Tube ROM (256KB, 5K used)
  0x00FFFFE0:
    size: 0x20
    labels:
      "l": Tube Registers

automatic:
  discontinuities:
    outline: "#487748"
    style: cut-out

  addresses:
    side: left
    start: true
    final_end: true
    end_exclusive: false

2. Install the memory layout tool:

pip install memory_layout

3. Generate an SVG:

python -m memory_layout riscv-bbcbasic.mld

I'm not sure if it's at all useful to you, but it was fun, and this is exactly the sort of thing that I created the tool for. If it's not useful, feel free to close. If it is useful, feel free to use, and close... It's just fun after all :-)

[hoglet67]

Thanks for this Charles,

I'll add it in to the wiki page tomorrow.

Dave

[hoglet67]

This is now included in the wiki page, thanks.