Merge pull request #141 from venomix666/nano6502

Port to the nano6502

README.md

@@ -31,6 +31,8 @@ to the 6502. So far it runs on:
 
   - Olimex' neo6502 6502-based computer.
 
+  - nano6502 6502-based SoC for the Tang Nano 20K FPGA board; TPA is 55kB.
+
 Unlike the original, it supports relocatable binaries, so allowing unmodified
 binaries to run on any system: this is necessary as 6502 systems tend to be
 much less standardised than 8080 and Z80 systems. (The systems above all load
@@ -57,6 +59,7 @@ No, it won't let you run 8080 programs on the 6502!
 <a href="doc/oric.png"><img src="doc/oric.png" style="width:40%" alt="CP/M-65 running on an Tangerine Oric 1"></a>
 <a href="doc/sorbus.png"><img src="doc/sorbus.png" style="width:40%" alt="CP/M-65 running on the Sorbus Computer"></a>
 <a href="doc/neo6502.png"><img src="doc/neo6502.png" style="width:40%" alt="CP/M-65 running on the Olimex neo6502"></a>
+<a href="doc/nano6502.png"><img src="doc/nano6502.png" style="width:40%" alt="CP/M-65 running on the nano6502"></a>
 </div>
 
 
@@ -309,6 +312,22 @@ the same time.
 
   - The console is 53x30. It has a SCREEN driver.
 
+### nano6502 notes
+
+  - The [nano6502](https://github.com/venomix666/nano6502/) is a 65C02-based SoC for the Tang Nano 20K FPGA board.
+   
+  - The CPU is running at 25.175 MHz (i.e. the pixel clock).
+
+  - It is using CPMFS directly on the microSD-card, with 15x1Mb partitions (drives `A` to `O`).
+
+  - The text output is over HDMI, with 640x480 video output and a 80x30 console. It has a SCREEN driver.
+
+  - The input is currently using the built in USB serial port. This way, this port can be run with only the Tang Nano 20K board without any specific carrier board.
+
+  - To use, write the `nano6502.img` file into the SD-card using `dd` or your preferred SD-card image writer. If you are updating the image and want to preserve the data on all drives except `A`, write the `nano6502_sysonly.img` instead.
+
+  - User area 1 on drive `A` contains utilities for setting the text and background colors, and a demo application which blinks the onboard LEDs.
+
 ### Supported programs
 
 Commands include `DUMP`, `STAT`, `COPY`, `SUBMIT`, `ASM`, `QE` and `BEDIT` plus

build.py

@@ -30,6 +30,8 @@
         "vic20.d64": "src/arch/commodore+vic20_diskimage",
         "x16.zip": "src/arch/x16+diskimage",
         "sorbus.zip": "src/arch/sorbus+diskimage",
+	"nano6502.img": "src/arch/nano6502+diskimage",
+	"nano6502_sysonly.img": "src/arch/nano6502+sysimage",
     },
     deps=[
         "tests"

src/arch/nano6502/build.py

@@ -0,0 +1,65 @@
+from build.ab import normalrule
+from tools.build import mkdfs, mkcpmfs
+from build.llvm import llvmrawprogram
+from config import (
+    MINIMAL_APPS,
+    MINIMAL_APPS_SRCS,
+    BIG_APPS,
+    BIG_APPS_SRCS,
+    SCREEN_APPS,
+    PASCAL_APPS,
+)
+
+llvmrawprogram(
+    name="nano6502",
+    srcs=["./nano6502.S"],
+    deps=["include", "src/lib+bioslib"],
+    linkscript="./nano6502.ld",
+)
+
+mkcpmfs(
+    name="cpmfs",
+    format="generic-1m",
+    items={"0:ccp.sys@sr": "src+ccp",
+	   "1:colorfg.com": "src/arch/nano6502/utils+colorfg",
+	   "1:colorbg.com": "src/arch/nano6502/utils+colorbg",
+	   "1:ledtest.com": "src/arch/nano6502/utils+ledtest"}
+    | MINIMAL_APPS
+    | MINIMAL_APPS_SRCS
+    | BIG_APPS
+    | BIG_APPS_SRCS
+    | SCREEN_APPS
+    | PASCAL_APPS,
+)
+
+mkcpmfs(
+    name="emptycpmfs",
+    format="generic-1m",
+    items="",
+)
+
+normalrule(
+    name="diskimage",
+    ins=[
+        ".+cpmfs",
+        ".+emptycpmfs",
+        ".+nano6502",
+        "src/bdos",
+    ],
+    outs=["nano6502.img"],
+    commands=["rm -f {outs[0]}","./src/arch/nano6502/buildimage.py"],
+    label="IMG",
+)
+
+normalrule(
+    name="sysimage",
+    ins=[
+        ".+cpmfs",
+        ".+nano6502",
+        "src/bdos",
+    ],
+    outs=["nano6502_sysonly.img"],
+    commands=["rm -f {outs[0]}","./src/arch/nano6502/buildsysimage.py"],
+    label="IMG",
+)
+

src/arch/nano6502/buildimage.py

@@ -0,0 +1,114 @@
+#!/usr/bin/python3
+
+import sys
+import os
+
+bootsector_size = 512
+bdos_offset = 512*256
+cpmfs_offset = 512*256
+cpmfs_size = 1024*1024
+
+bios_filename = '.obj/src/arch/nano6502/+nano6502/+nano6502'
+bdos_filename = '.obj/src/bdos/+bdos/+bdos'
+cpmfs_filename = '.obj/src/arch/nano6502/+cpmfs/src/arch/nano6502/+cpmfs.img'
+cpmfs_empty_filename = '.obj/src/arch/nano6502/+emptycpmfs/src/arch/nano6502/+emptycpmfs.img'
+output_filename = '.obj/src/arch/nano6502/+diskimage/nano6502.img'
+
+size = os.path.getsize(bios_filename)
+
+outfile=open(output_filename, "wb")
+
+# Write boot sector
+# Boot sector format
+# Magic number: 0x6E, 0x61, 0x6E, 0x6F
+# SD sector to load - 4 bytes
+# Number of pages to load - 1 byte
+# Page to load data to - 1 byte
+# Total 10 bytes
+# Padding 502 bytes
+
+bootsector_data = [0x6E, 0x61, 0x6E, 0x6F, 0x00, 0x00, 0x00, 0x01, 0x05, 0x03]
+
+for d in bootsector_data:
+    outfile.write(d.to_bytes(1, "little"))
+
+out=0
+for i in range(bootsector_size - len(bootsector_data)):
+    outfile.write(out.to_bytes(1, "little"))
+
+# Write BIOS
+
+infile=open(bios_filename, "rb")
+byte=infile.read(1)
+
+# Write BIOS
+while byte:
+    outfile.write(byte)
+    byte=infile.read(1)
+
+padding = bdos_offset - size - bootsector_size
+out = 0
+
+while padding:
+    outfile.write(out.to_bytes(1,"little"))
+    padding = padding - 1;
+
+infile.close()
+
+# Write BDOS
+size = os.path.getsize(bdos_filename)
+
+infile = open(bdos_filename, "rb")
+
+byte=infile.read(1)
+while byte:
+    outfile.write(byte)
+    byte=infile.read(1)
+
+padding = cpmfs_offset - size;
+out = 0
+
+while padding:
+    outfile.write(out.to_bytes(1,"little"))
+    padding = padding - 1;
+
+infile.close()
+
+# Write CPMFS
+size = os.path.getsize(cpmfs_filename)
+
+infile = open(cpmfs_filename, "rb")
+
+byte=infile.read(1)
+while byte:
+    outfile.write(byte)
+    byte=infile.read(1)
+
+padding = cpmfs_size - size;
+out=0
+while padding:
+    outfile.write(out.to_bytes(1,"little"))
+    padding = padding - 1;
+
+infile.close()
+
+# Write empty drives B-O
+for i in range(15):
+    size = os.path.getsize(cpmfs_empty_filename)
+
+    infile = open(cpmfs_empty_filename, "rb")
+
+    byte=infile.read(1)
+    while byte:
+        outfile.write(byte)
+        byte=infile.read(1)
+
+    padding = cpmfs_size - size;
+    out=0
+    while padding:
+        outfile.write(out.to_bytes(1,"little"))
+        padding = padding - 1;
+
+    infile.close()
+
+outfile.close()

src/arch/nano6502/buildsysimage.py

@@ -0,0 +1,94 @@
+#!/usr/bin/python3
+
+import sys
+import os
+
+bootsector_size = 512
+bdos_offset = 512*256
+cpmfs_offset = 512*256
+cpmfs_size = 1024*1024
+
+bios_filename = '.obj/src/arch/nano6502/+nano6502/+nano6502'
+bdos_filename = '.obj/src/bdos/+bdos/+bdos'
+cpmfs_filename = '.obj/src/arch/nano6502/+cpmfs/src/arch/nano6502/+cpmfs.img'
+cpmfs_empty_filename = '.obj/src/arch/nano6502/+emptycpmfs/src/arch/nano6502/+emptycpmfs.img'
+output_filename = '.obj/src/arch/nano6502/+sysimage/nano6502_sysonly.img'
+
+size = os.path.getsize(bios_filename)
+
+outfile=open(output_filename, "wb")
+
+# Write boot sector
+# Boot sector format
+# Magic number: 0x6E, 0x61, 0x6E, 0x6F
+# SD sector to load - 4 bytes
+# Number of pages to load - 1 byte
+# Page to load data to - 1 byte
+# Total 10 bytes
+# Padding 502 bytes
+
+bootsector_data = [0x6E, 0x61, 0x6E, 0x6F, 0x00, 0x00, 0x00, 0x01, 0x05, 0x03]
+
+for d in bootsector_data:
+    outfile.write(d.to_bytes(1, "little"))
+
+out=0
+for i in range(bootsector_size - len(bootsector_data)):
+    outfile.write(out.to_bytes(1, "little"))
+
+# Write BIOS
+
+infile=open(bios_filename, "rb")
+byte=infile.read(1)
+
+# Write BIOS
+while byte:
+    outfile.write(byte)
+    byte=infile.read(1)
+
+padding = bdos_offset - size - bootsector_size
+out = 0
+
+while padding:
+    outfile.write(out.to_bytes(1,"little"))
+    padding = padding - 1;
+
+infile.close()
+
+# Write BDOS
+size = os.path.getsize(bdos_filename)
+
+infile = open(bdos_filename, "rb")
+
+byte=infile.read(1)
+while byte:
+    outfile.write(byte)
+    byte=infile.read(1)
+
+padding = cpmfs_offset - size;
+out = 0
+
+while padding:
+    outfile.write(out.to_bytes(1,"little"))
+    padding = padding - 1;
+
+infile.close()
+
+# Write CPMFS
+size = os.path.getsize(cpmfs_filename)
+
+infile = open(cpmfs_filename, "rb")
+
+byte=infile.read(1)
+while byte:
+    outfile.write(byte)
+    byte=infile.read(1)
+
+padding = cpmfs_size - size;
+out=0
+while padding:
+    outfile.write(out.to_bytes(1,"little"))
+    padding = padding - 1;
+
+infile.close()
+outfile.close()