Recompiling CP/M 2.2 from the sources
cd ~/z80pack-x.y/cpmsim/disks mv drivei.cpm library/hd-tools.dskThis is not required with z80pack releases later than 1.8, the disk setup in the distribution is done appropriate already.
Download and Installation of the disk images:
Download the archive with the disk images and unpack the archive under ~/z80pack-x.y/cpmsim with tar xzvf cpm2src.tgz. Type cpm2src to mount the disks and start the emulation, the script checks if the drives c:, d: and i: are empty, before formating and mounting disks.
Drive a: contains a CP/M 2.2 system, the ISIS interface to CP/M 2.2 and
the necessary tools. Also the ISIS assembler asm80 is on drive a.
Drive b: contains the ISIS PL/M-80 compiler, linker and tools needed to compile and link the CP/M programs written in PL/M-80.
Drive c: is the scratch disk used by the build scripts.
Drive d: is the destination disk, we are going to build a bootable CP/M 2.2 from the sources on this drive.
Drive i: includes the CP/M 2.2 sources.
The ISIS environment included on the both tool disks is the minimal required set for building CP/M 2.2, due to drive size limitations. More complete ISIS tool disks are available as separate download.
Compiling the transient programs:
The new OS on drive d: is build with a few batch commands:
submit cmd1 submit cmd2 <- this will break ed, don't execute, needs to be fixed submit cmd3 submit cmd4 submit cmd5Compiling the kernel:
submit kernel-m build for Intel MDS800, as it was distributed by DRI submit kernel-s build for Z80 simulator, you probably want thisCreating a bootable disk:
d:movcpm 64 * save 34 d:cpm64.sys d:sysgen d:cpm64.sys type d for destination drive, followed by two CRThe new build movpm program might not work on your current system, DRI used a lot of serialization code in cpmove.asm to verify the kernel in movcpm.com with the current running one. The program will run into a HALT opcode which will abort the emulation, in case the versions don't match. To overcome this problem run movcpm under control of ddt and patch out the jumps to the error handler:
ddt d:movcpm.com DDT VERS 2.2 NEXT PC 2700 0100 -s234 0234 C2 0 0235 5A 0 0236 02 0 0237 02 . -s2cb 02CB C2 0 02CC 5A 0 02CD 02 0 02CE 23 . -i64 * -g CONSTRUCTING 64k CP/M vers 2.2 READY FOR "SYSGEN" OR "SAVE 34 CPM64.COM"To try out the new disk leave cpmsim, move the disk image from drive d: to drive a: and start cpmsim, if everything went ok CP/M 2.2 will boot.
Patched CP/M 2.2 source disk:
There is a second harddisk image available for download with some of the official DRI patches applied to the sources. Because this archive includes the harddisk image and shell script to mount disks only, the original source archive must be installed first.
|Patches applied so far|
|CPM22APN.02||OS3BDOS.ASM||make RUBOUT identical to BACKSPACE|
|CPM22PAT.03||SUBMIT.PLM||Create $$$.SUB always on A:, so that a submit job can run from any drive|
|CPM22APN.12||SUBMIT.PLM||Do not convert input to upper case. Try i:subtest.sub for example|
In the sources the original code is commented out and the modification is commented with the patch number in this form: ***CPM22APN.02***.
Building a CP/M 2.2 kernel for other systems:
This can easily be done by using kernel-s.sub as a start. Modify the script to use boot and BIOS code for the destination system, instead of using boot.z80 and bios.asm for the Z80 emulation. The boot code needs to be originated at the address, where the boot ROM loads it into memory, movcpm doesn't relocate the boot code. A custom BIOS needs to be originated at address 1600H for the relocation.
Questions and Answers:
|Q:||Why are there relocation errors when building ddt, xsub and movcpm?|
|A:||The genmod utility normaly is used to build page relocatable binaries. The program is abused a bit, by building executables including a non relocatable module, the loader, and a relocatable module. The relocation errors are warnings about the non relocatable parts of the programs and can be ignored.|