DOS ain't dead

roytam 08.01.2024, 07:26 @ ecm	Enhanced DR-DOS single-file load (2023 December revision) Post reply
	> I prepared a blog post at > https://pushbx.org/ecm/dokuwiki/blog/pushbx/2024/0107_enhanced_dr-dos_single-file_load > > Basically, I converted EDR-DOS to load from a single kernel file. cool, this is kind of DR-DOS 7.06.

Guti

10.01.2024, 17:09

@ ecm

Enhanced DR-DOS single-file load (2023 December revision)

Post reply

> I prepared a blog post at
> https://pushbx.org/ecm/dokuwiki/blog/pushbx/2024/0107_enhanced_dr-dos_single-file_load
>
> Basically, I converted EDR-DOS to load from a single kernel file.

Good work. As your post stated, it open the doors to future improvements. Glad to see EDR is alive with you!

---
Visit my personal blog at https://www.javiergutierrezchamorro.com

Ro2003

13.01.2024, 09:28

@ ecm

Enhanced DR-DOS single-file load (2023 December revision)

Post reply

> I prepared a blog post at
> https://pushbx.org/ecm/dokuwiki/blog/pushbx/2024/0107_enhanced_dr-dos_single-file_load
>
> Basically, I converted EDR-DOS to load from a single kernel file.

Great - both the changes and the blog post!
Can you please arrange for binary builds to be generated?

Does it support the LBA 33-bit?

Can you mention if some other features from lDOS, RxDOS, DR-DOS 7.03/8.x are not yet supported?

From your blog post I understand that December 2023 kernel can be booted from boot sectors of lDOS / RxDOS.3, FreeDOS, Enhanced DR-DOS, MS-DOS v6 / IBM-DOS, MS-DOS v7, Multiboot v1, Multiboot v2, NTLDR, BOOTMGR, or DOS-C IPL.SYS.

What about:
- booting from bootsectors of other DR-DOS (3.31-7.05), PC DOS 7.10
- boot sector that allows booting EDR-DOS, FreeDOS, PC DOS, MS-DOS v6, MS-DOS v7/8, DR-DOS
- boot sector that allows booting from GPT
- using COMMAND.COM from another DOS as main SHELL with the December 2023 kernel? (e.g. how much of these and these are implemented?) - the opposite question of this one.

ecm

Düsseldorf, Germany,
14.01.2024, 22:58

@ Ro2003

Enhanced DR-DOS development

Post reply

> > I prepared a blog post at
> >
> https://pushbx.org/ecm/dokuwiki/blog/pushbx/2024/0107_enhanced_dr-dos_single-file_load
> >
> > Basically, I converted EDR-DOS to load from a single kernel file.
>
> Great - both the changes and the blog post!
> Can you please arrange for binary builds to be generated?

My repo already has automatic (daily) current builds. You can find the most recent current build in https://pushbx.org/ecm/download/edrdos.zip - This file will be updated to a 2024 January revision within the next 1 hour as of this posting. This revision includes most of the patches from the SvarDOS repository, excluding some for building with OpenWatcom make and wlink instead.

All four kernel files are found in the root of the zipball. The shell is in command/bin/command.com as before. The files drbio.bin and drdos.sys exist in the subdirectories but are used only to build the single-file kernels, not needed otherwise.

> Does it support the
> LBA 33-bit?

No, not yet.

> Can you mention if some other features from lDOS, RxDOS, DR-DOS 7.03/8.x
> are not yet supported?

RxDOS comes with an LFN server built in (corresponding to the DOSLFN tool), but this is very incomplete and not fully compatible.

> From your blog post I understand that December 2023 kernel

This is only true of the kernel files using iniload, the *.com files. The *.sys files only support loading as FreeDOS or EDR-DOS kernels.

> can be booted
> from boot sectors of lDOS / RxDOS.3, FreeDOS, Enhanced DR-DOS, MS-DOS v6 /
> IBM-DOS, MS-DOS v7, Multiboot v1, Multiboot v2, NTLDR, BOOTMGR, or DOS-C
> IPL.SYS.

Yes, but don't say the last ones too loudly.

> What about:
> - booting from bootsectors of other DR-DOS (3.31-7.05),

I would have to test and/or study these. If you can provide images that use them I can look into it.

> PC DOS 7.10

The IBM-DOS entry of lDOS iniload does support PC-DOS 7.10 load, including from FAT32.

> - boot sector that allows booting EDR-DOS, FreeDOS, PC DOS, MS-DOS v6,
> MS-DOS v7/8, DR-DOS

My ldosboot boot sector loaders can be built to cover a number of protocols, though you may need to disable some options to make them fit. It is easier to set up lDebug (using any sector-to-iniload protocol to load the debugger) then enter a boot protocol=PROTOCOLNAME command and upon success run a Q command to make the debugger hand over control to the next kernel.

> - boot sector that allows
> booting
> from GPT

You need another loader stage to replace the traditional MBR loader which will load and pass control to the boot sector loader. Other than the 32-bit or 33-bit LBA limits most boot sector loaders do not care whether they are running on a GPT, MBR primary, or MBR logical partition.

> - using COMMAND.COM from another DOS as main SHELL with the December 2023
> kernel? (e.g. how much of
> these
> and these are implemented?) -
> the opposite question of
> this one.

I mostly work on the kernels. If you have any particular feature of another shell that doesn't work on this kernel, feel free to specify.

---
l

ecm

Düsseldorf, Germany,
20.01.2024, 13:24

@ ecm

lDebug boot loading other kernels

Post reply

> > - boot sector that allows booting EDR-DOS, FreeDOS, PC DOS, MS-DOS v6,
> > MS-DOS v7/8, DR-DOS
>
> My ldosboot boot sector loaders can be built to cover a number of
> protocols, though you may need to disable some options to make them fit. It
> is easier to set up lDebug (using any sector-to-iniload protocol to load
> the debugger) then enter a boot protocol=PROTOCOLNAME command
> and upon success run a Q command to make the debugger hand over control to
> the next kernel.

By the way, you can load a kernel file from any subdirectory of a (FAT12, FAT16, or FAT32) file system. For instance, boot protocol ldos hda1/kernels/edrdos.com could be used to load EDR-DOS from a subdirectory. Further, I fixed a bug recently which makes it so you can now load traditional dual-file kernels (MS-DOS v6 or IBM-DOS, but not old EDR-DOS) from any two subdirectories. boot protocol msdos6 fda/msdosio/msdos6io.sys /msdosdos/msdos6.sys would work. If the files are in the same directory, a command like boot protocol msdos6 fda/msdos/msdos6io.sys msdos6.sys works too (if the add name doesn't contain a slash it is in the same directory as the kernel name). Details in the manual.

---
l

CandyMan 07.06.2024, 16:19 @ ecm	Enhanced DR-DOS single-file load (2023 December revision) Post reply
	Modified EDR-DOS cannot enter to one of the directories on my hard drive. I tested kernel from 19 may 2024. https://pushbx.org/ecm/download/old/edrdos/20240519.zip

ecm

Düsseldorf, Germany,
07.06.2024, 17:12

@ CandyMan

Enhanced DR-DOS single-file load (2023 December revision)

Post reply

> Modified EDR-DOS cannot enter to one of the directories on my hard drive.
>
> I tested kernel from 19 may 2024.
>
> https://pushbx.org/ecm/download/old/edrdos/20240519.zip

Does any earlier revision, including Udo Kuhnt's, work? Do other DOS versions work? What exactly does "cannot enter" mean, a CD command fails for this directory? Can you create a disk image that reproduces the problem in qemu? (Preferably with as little data on the drive as possible.)

---
l

CandyMan

07.06.2024, 18:56

@ ecm

Enhanced DR-DOS single-file load (2023 December revision)

Post reply

> > Modified EDR-DOS cannot enter to one of the directories on my hard
> drive.
> >
> > I tested kernel from 19 may 2024.
> >
> > https://pushbx.org/ecm/download/old/edrdos/20240519.zip
>
> Does any earlier revision, including Udo Kuhnt's, work? Do other DOS
> versions work? What exactly does "cannot enter" mean, a CD
> command fails for this directory? Can you create a disk image that
> reproduces the problem in qemu? (Preferably with as little data on the
> drive as possible.)

The kernels of other clones work and so do previous versions of EDR-DOS (I tested until August 2023). The CD command does not work and neither does trying to enter the directory with e.g. Volkov Commander. I suspect that these are directories with a cluster larger than 65535. My disk is USB FAT32 - 32GB.

ecm

Düsseldorf, Germany,
07.06.2024, 19:42

@ CandyMan

Enhanced DR-DOS - CD bug

Post reply

> The kernels of other clones work and so do previous versions of EDR-DOS (I
> tested until August 2023).

What exact revision is the latest that works?

> The CD command does not work and neither does
> trying to enter the directory with e.g. Volkov Commander. I suspect that
> these are directories with a cluster larger than 65535. My disk is USB
> FAT32 - 32GB.

I'll see about trying this later.

---
l

ecm

Düsseldorf, Germany,
07.06.2024, 19:47

@ ecm

Enhanced DR-DOS - CD bug

Post reply

> > The kernels of other clones work and so do previous versions of EDR-DOS
> (I
> > tested until August 2023).
>
> What exact revision is the latest that works?

This could be cause for an error: https://hg.pushbx.org/ecm/edrdos/rev/8d3b6d9a415d

Does this one work?: https://pushbx.org/ecm/download/old/edrdos/20231205.zip

---
l

CandyMan 07.06.2024, 22:10 @ ecm	Enhanced DR-DOS - CD bug Post reply
	> > What exact revision is the latest that works? Version <= 20240114.zip works fine Version >= 20240329.zip doesn't work

ecm

Düsseldorf, Germany,
07.06.2024, 23:17

@ CandyMan

Enhanced DR-DOS - CD bug

Post reply

> > > What exact revision is the latest that works?
>
> Version <= 20240114.zip works fine
> Version >= 20240329.zip doesn't work

I was able to reproduce, CD to a directory causes a critical error prompt. I built a hard disk image like this: nasm -D_MEDIAID=0F8h -D_SPF=2000 ../bootimg/bootimg.asm -I ../bootimg/ -I ../lmacros/ -D_MBR -D_BPE=32 -D_MBR_PART_TYPE=fat32 -o big32.img -D_PAYLOADFILE=::fill,'(512 * 76000),26h,fill.dat,::chdir,testdir,::fill,32,32,test.dat' -D_SPI=256000

I am fairly sure that a SvarDOS contribution changing the LBA flagging is to blame: https://hg.pushbx.org/ecm/edrdos/rev/220f54eecbb8 From https://github.com/SvarDOS/edrdos/commit/99765bd4c9ec9e035f1bd2af191c35d440c99383

It changed the LBA use to be indicated by the UDF_LBA flag. However, in add_unit this flag is cleared: https://hg.pushbx.org/ecm/edrdos/file/1137afe0115d/drbio/disk.asm#l616

The next changeset will fix this problem, please test today's June build in 45min from now.

---
l

ecm

Düsseldorf, Germany,
07.06.2024, 23:24

@ ecm

Enhanced DR-DOS - CD bug

Post reply

> > > > What exact revision is the latest that works?
> >
> > Version <= 20240114.zip works fine
> > Version >= 20240329.zip doesn't work
>
> I was able to reproduce, CD to a directory causes a critical error prompt.
> I built a hard disk image like this: nasm -D_MEDIAID=0F8h -D_SPF=2000> ../bootimg/bootimg.asm -I ../bootimg/ -I ../lmacros/ -D_MBR -D_BPE=32 > -D_MBR_PART_TYPE=fat32 -o big32.img -D_PAYLOADFILE=::fill,'(512 * > 76000),26h,fill.dat,::chdir,testdir,::fill,32,32,test.dat' > -D_SPI=256000
>
> I am fairly sure that a SvarDOS contribution changing the LBA flagging is
> to blame: https://hg.pushbx.org/ecm/edrdos/rev/220f54eecbb8 From
> https://github.com/SvarDOS/edrdos/commit/99765bd4c9ec9e035f1bd2af191c35d440c99383
>
> It changed the LBA use to be indicated by the UDF_LBA flag.
> However, in add_unit this flag is cleared:
> https://hg.pushbx.org/ecm/edrdos/file/1137afe0115d/drbio/disk.asm#l616
>
> The next changeset will fix this problem, please test today's June build in
> 45min from now.

This is the fix changeset: https://hg.pushbx.org/ecm/edrdos/rev/dde66e015fb8

---
l

CandyMan

03.07.2024, 18:54

@ ecm

FAT32 search on GPT partition

Post reply

This code may be added to EDR-DOS sources.
GPT_Signature equ 00h GPT_Revision equ 08h GPT_HeaderSize equ 0Ch GPT_HeaderCRC equ 10h GPT_Reserved equ 14h GPT_CurrentLBA equ 18h GPT_BackupLBA equ 20h GPT_FirstUsableLBA equ 28h GPT_LastUsableLBA equ 30h GPT_DiskGUID equ 38h GPT_PartitionsLBA equ 48h GPT_PartitionNumber equ 50h GPT_PartitionEntrySize equ 54h GPTEntry_PartitionGUID equ 00h GPTEntry_uniqGUID equ 10h GPTEntry_StartLBA equ 20h GPTEntry_EndLBA equ 28h GPTEntry_Attributes equ 30h GPTEntry_Name equ 38h db 'GPT',0 ;gpt code flag gpt_init: nop ;to modify by hex editor to "ret" - 0xC3 mov dl,80h ;start from 1st hard disk ;push di ya_gpt: xor di,di ;\ start from zero partition xor bx,bx ;/ again_gpt: cmp nunits,MAXPART ; do we already have the maximum? jae lt_gpt ; skip if space for more units lea si,diskaddrpack ; pointer to disk address packet mov word ptr [si+ 8],1 ;\ make dword = 1 and word ptr [si+10],0 ;/ push bx call login_read_dx_lba ; read sector pop bx jc no_gpt mov si,CG:local_buffer ; check if sector start lodsw ; with "EFI PART" string cmp ax,"FE" jnz no_gpt lodsw cmp ax," I" jnz no_gpt lodsw cmp ax,"AP" jnz no_gpt lodsw cmp ax,"TR" jnz no_gpt ; start from, qword = 2? cmp word ptr [si+GPT_PartitionsLBA-4*2+0],2 jnz no_gpt xor ax,ax cmp [si+GPT_PartitionsLBA-4*2+2],ax jnz no_gpt cmp [si+GPT_PartitionsLBA-4*2+4],ax jnz no_gpt cmp [si+GPT_PartitionsLBA-4*2+6],ax jnz no_gpt ; partition size, qword = 80h? cmp word ptr [si+GPT_PartitionEntrySize-4*2+0],0080h jnz no_gpt cmp word ptr [si+GPT_PartitionEntrySize-4*2+2],ax jnz no_gpt ; save number of partitons push word ptr [si+GPT_PartitionNumber-4*2+2] push word ptr [si+GPT_PartitionNumber-4*2+0] ; save LBA sector number (dword) push word ptr [si+GPT_PartitionsLBA-4*2+2] push word ptr [si+GPT_PartitionsLBA-4*2+0] lea si,diskaddrpack ; copy LBA sector number to packet and load this sector pop word ptr [si+ 8] pop word ptr [si+10] ; make partition number division by 4 mov ax,di mov cx,bx shr cx,1 rcr ax,1 shr cx,1 rcr ax,1 ; add division result to the sector number add word ptr [si+ 8],ax adc word ptr [si+10],cx push bx call login_read_dx_lba ; read sector pop bx jc er_gpt ; make pointer to 128 bytes structure in sector (512/128=4) mov ax,di and ax,3 mov cl,80h mul cl add ax,CG:local_buffer mov si,ax ; load LBA disk starting sector number mov ax,[si+GPTEntry_StartLBA+0*8+0] mov cx,[si+GPTEntry_StartLBA+0*8+2] ; save partition start mov word ptr [partstart+0],ax mov word ptr [partstart+2],cx ; zero ? or ax,cx jz nx_gpt ; if partition finish (dword +4)<>0 then skip mov ax,[si+GPTEntry_EndLBA+4+2] or ax,[si+GPTEntry_EndLBA+4+0] jnz nx_gpt ; save partition finish mov ax,[si+GPTEntry_EndLBA+2] mov word ptr [partend+2],ax mov ax,[si+GPTEntry_EndLBA+0] mov word ptr [partend+0],ax mov ax,word ptr [partstart+0] mov cx,word ptr [partstart+2] ; compute partition size mov si,word ptr [partend+0] sub si,ax mov word ptr [part_size+0],si mov si,word ptr [partend+2] sbb si,cx mov word ptr [part_size+2],si add word ptr [part_size+0],1 adc word ptr [part_size+2],0 lea si,diskaddrpack ; pointer to disk address packet mov word ptr [si+ 8],ax mov word ptr [si+10],cx push bx call login_read_dx_lba ; read 1st partition sector pop bx jc nx_gpt mov si,CG:local_buffer mov ax,[si+52h] ;\ cmp ax,"AF" ; \ jnz nx_gpt ; > = "FAT"? to skip NTFS mov al,[si+54h] ; / cmp al,"T" ;/ jnz nx_gpt mov [parttype],FAT32X_ID pushx <di,bx,dx> call login_p0 ; add and register new disk popx <dx,bx,di> nx_gpt: add di,1 ;\ next partition adc bx,0 ;/ pop ax ;\ left partitions pop cx ;/ cmp cx,bx jnz again_gpt cmp ax,di jnz again_gpt jmp no_gpt er_gpt: add sp,2*2 no_gpt: inc dl ; next hard disk to check jnz ya_gpt ; if ZF=0 jump lt_gpt: ;pop di ret

tom Germany (West), 03.07.2024, 19:48 @ CandyMan	FAT32 search on GPT partition Post reply
	> This code may be added to EDR-DOS sources. As I said: just 187 assembly lines (including empty lines). more like 50 lines in C. What is missing is the part where partition start and ending offsets are beyond 2^32 (almost trivial) AND WHERE TO STORE these offsets, adding them to LBA48 offsets before passing to the BIOS.

tom Germany (West), 03.07.2024, 19:51 @ tom	FAT32 search on GPT partition Post reply
	> This code may be added to EDR-DOS sources. As I said: just 187 assembly lines (including empty lines). probably more like 50 lines in C. What is missing is the part where partition start and ending offsets are beyond 2^32 (almost trivial) AND WHERE TO STORE these offsets, adding them to LBA48 offsets before passing them to the BIOS.

CandyMan

03.07.2024, 20:55

@ tom

FAT32 search on GPT partition

Post reply

> > This code may be added to EDR-DOS sources.
>
> As I said: just 187 assembly lines (including empty lines).
>
> probably more like 50 lines in C.
>
> What is missing is the part where partition start and ending offsets are
> beyond 2^32 (almost trivial) AND WHERE TO STORE these offsets, adding them
> to
> LBA48 offsets before passing them to the BIOS.

I made some small corrections. Thanks.
GPT_Signature equ 00h GPT_Revision equ 08h GPT_HeaderSize equ 0Ch GPT_HeaderCRC equ 10h GPT_Reserved equ 14h GPT_CurrentLBA equ 18h GPT_BackupLBA equ 20h GPT_FirstUsableLBA equ 28h GPT_LastUsableLBA equ 30h GPT_DiskGUID equ 38h GPT_PartitionsLBA equ 48h GPT_PartitionNumber equ 50h GPT_PartitionEntrySize equ 54h GPTEntry_PartitionGUID equ 00h GPTEntry_uniqGUID equ 10h GPTEntry_StartLBA equ 20h GPTEntry_EndLBA equ 28h GPTEntry_Attributes equ 30h GPTEntry_Name equ 38h db 'GPT',0 ;gpt code flag gpt_init: nop ;to modify by hex editor to "ret" - 0xC3 mov dl,80h ;start from 1st hard disk ;push di ya_gpt: xor di,di ;\ start from zero partition xor bx,bx ;/ again_gpt: cmp nunits,MAXPART ; do we already have the maximum? jae lt_gpt ; skip if space for more units lea si,diskaddrpack ; pointer to disk address packet mov word ptr [si+ 8],1 ;\ make dword = 1 and word ptr [si+10],0 ;/ push bx call login_read_dx_lba ; read sector pop bx jc no_gpt mov si,CG:local_buffer ; check if sector start lodsw ; with "EFI PART" string cmp ax,"FE" jnz no_gpt lodsw cmp ax," I" jnz no_gpt lodsw cmp ax,"AP" jnz no_gpt lodsw cmp ax,"TR" jnz no_gpt ; start from, qword = 2? cmp word ptr [si+GPT_PartitionsLBA-4*2+0],2 jnz no_gpt xor ax,ax cmp [si+GPT_PartitionsLBA-4*2+2],ax jnz no_gpt cmp [si+GPT_PartitionsLBA-4*2+4],ax jnz no_gpt cmp [si+GPT_PartitionsLBA-4*2+6],ax jnz no_gpt ; partition size, qword = 80h? cmp word ptr [si+GPT_PartitionEntrySize-4*2+0],0080h jnz no_gpt cmp word ptr [si+GPT_PartitionEntrySize-4*2+2],ax jnz no_gpt ; save number of partitons push word ptr [si+GPT_PartitionNumber-4*2+2] push word ptr [si+GPT_PartitionNumber-4*2+0] ; save LBA sector number (dword) push word ptr [si+GPT_PartitionsLBA-4*2+2] push word ptr [si+GPT_PartitionsLBA-4*2+0] lea si,diskaddrpack ; copy LBA sector number to packet and load this sector pop word ptr [si+ 8] pop word ptr [si+10] ; make partition number division by 4 mov ax,di mov cx,bx shr cx,1 rcr ax,1 shr cx,1 rcr ax,1 ; add division result to the sector number add word ptr [si+ 8],ax adc word ptr [si+10],cx push bx call login_read_dx_lba ; read sector pop bx jc er_gpt ; make pointer to 128 bytes structure in sector (512/128=4) mov ax,di and ax,3 mov cl,80h mul cl add ax,CG:local_buffer mov si,ax ; StartLBA >= 2^32 mov ax,[si+GPTEntry_StartLBA+4+0] or ax,[si+GPTEntry_StartLBA+4+2] jnz nx_gpt ; load LBA disk starting sector number mov ax,[si+GPTEntry_StartLBA+0*8+0] mov cx,[si+GPTEntry_StartLBA+0*8+2] ; save partition start mov word ptr [partstart+0],ax mov word ptr [partstart+2],cx ; zero ? or ax,cx jz nx_gpt ; if partition finish (dword +4)<>0 then skip (EndLBA >= 2^32) mov ax,[si+GPTEntry_EndLBA+4+2] or ax,[si+GPTEntry_EndLBA+4+0] jnz nx_gpt ; save partition finish mov ax,[si+GPTEntry_EndLBA+2] mov word ptr [partend+2],ax mov ax,[si+GPTEntry_EndLBA+0] mov word ptr [partend+0],ax mov ax,word ptr [partstart+0] mov cx,word ptr [partstart+2] ; compute partition size mov si,word ptr [partend+0] sub si,ax mov word ptr [part_size+0],si mov si,word ptr [partend+2] sbb si,cx jc nx_gpt ; overflow? yes, skip mov word ptr [part_size+2],si add word ptr [part_size+0],1 adc word ptr [part_size+2],0 lea si,diskaddrpack ; pointer to disk address packet mov word ptr [si+ 8],ax mov word ptr [si+10],cx push bx call login_read_dx_lba ; read 1st partition sector pop bx jc nx_gpt mov si,CG:local_buffer mov ax,[si+52h] ;\ cmp ax,"AF" ; \ jnz nx_gpt ; > = "FAT"? to skip NTFS mov al,[si+54h] ; / cmp al,"T" ;/ jnz nx_gpt mov [parttype],FAT32X_ID pushx <di,bx,dx> call login_p0 ; add and register new disk popx <dx,bx,di> nx_gpt: add di,1 ;\ next partition adc bx,0 ;/ pop ax ;\ left partitions pop cx ;/ cmp cx,bx jnz again_gpt cmp ax,di jnz again_gpt jmp no_gpt er_gpt: add sp,2*2 no_gpt: inc dl ; next hard disk to check jnz ya_gpt ; if ZF=0 jump lt_gpt: ;pop di ret

boeckmann

Aachen, Germany,
08.07.2024, 22:31

@ CandyMan

Kernel ported to JWasm

Post reply

I finished porting the EDR-DOS kernel[1] to JWasm and was able to build it under DOS, Win32 and MacOS. This should also build under Linux. OpenWatcom, specifically wmake, wlink and exe2bin are additional build requirements for building drbio.sys and drdos.sys. The command.com build also depends on the Watcom C compiler.

Porting required some manual steps, opening the door for human errors. Time will tell how many of them I added to the source...

[1] https://github.com/SvarDOS/edrdos

boeckmann Aachen, Germany, 09.07.2024, 18:22 @ boeckmann	Kernel ported to JWasm Post reply
	Binaries and a 1.44M floppy image are now automatically generated via Github workflows. They can be downloaded from https://github.com/SvarDOS/edrdos/actions. Click on the last successful workflow run to get to the files...

Japheth

Germany (South),
10.07.2024, 17:32

@ boeckmann

Kernel ported to JWasm

Post reply

> Binaries and a 1.44M floppy image are now automatically generated via
> Github workflows. They can be downloaded from
> https://github.com/SvarDOS/edrdos/actions. Click on the last successful
> workflow run to get to the files...

https://github.com/SvarDOS/edrdos/actions

---
MS-DOS forever!

ecm

Düsseldorf, Germany,
14.07.2024, 21:03

@ boeckmann

EDR-DOS kernel ported to JWasm - ident86 validated DRBIO port

Post reply

> I finished porting the EDR-DOS kernel[1] to JWasm and was able to build it
> under DOS, Win32 and MacOS. This should also build under Linux. OpenWatcom,
> specifically wmake, wlink and exe2bin are additional build requirements for
> building drbio.sys and drdos.sys. The command.com build also depends on the
> Watcom C compiler.
>
> Porting required some manual steps, opening the door for human errors. Time
> will tell how many of them I added to the source...
>
> [1] https://github.com/SvarDOS/edrdos

I picked most of the changes to port DRBIO into my EDR-DOS repo. I used my new identicalising tool ident86 to validate that all changes in the binary are due to different encoding choices that have the same meaning in the disassembly. I wrote about this on my blog.

It turns out your DRBIO port seems to be completely right, except for a few problems along the way like the initcode: WRT keyword you used in this commit for nlsfunc.asm which you silently undid in a commit described as "convert bdosldr.a86 to JWASM". That's not good. I also made sure in my picks to separately copy, move, rename, or delete files in separate changesets that do not change any of the content in the same changeset, to simplify following the changes if you were to inspect the revisions' logs.

I didn't get around to applying the same process to the DRDOS module yet. As mentioned, this may require a small adjustment to ident86 to work with the DRDOS binary and its associated trace listing file drdos.tls created by the scripts in my build.

---
l

boeckmann

Aachen, Germany,
14.07.2024, 22:37

@ ecm

EDR-DOS kernel ported to JWasm - ident86 validated DRBIO port

Post reply

> It turns out your DRBIO port seems to be completely right, except for a few
> problems along the way like the initcode: WRT keyword you used
> in
> this commit for nlsfunc.asm which you silently undid
> in
> a commit described as "convert bdosldr.a86 to JWASM". That's not
> good. I also made sure in my picks to separately copy, move, rename, or
> delete files in separate changesets that do not change any of the content
> in the same changeset, to simplify following the changes if you were to
> inspect the revisions' logs.

Really helpful having someone double checking this! Thanks.

I learned a couple of things. Especially what not to do when converting a file: Copy it to a new file, convert the new file, check in the new file, and delete the old file. Good reciepe to make tracking the changes via commit log really hard. Better way is to commit as the original file and then rename. So you get a more meaningful diff. I tried to follow this later when porting DRDOS component.

>
> I didn't get around to applying the same process to the DRDOS module yet.
> As mentioned, this may require a small adjustment to ident86 to work with
> the DRDOS binary and its associated trace listing file drdos.tls created by
> the scripts in my build.

In contrast to the port of DRBIO, I tried not to introduce offset changes resulting from different instruction encodings, inserting NOPs etc. if needed. Made life easier when doing binary comparisons.

CandyMan 22.07.2024, 16:57 @ boeckmann	EDR-DOS kernel ported to JWasm - ident86 validated DRBIO port Post reply
	It would be useful to change some instructions "LEA Dst,Addr" to the shorter "MOV Dst,OFFSET Addr"

boeckmann Aachen, Germany, 23.07.2024, 20:50 @ CandyMan	EDR-DOS kernel ported to JWasm - ident86 validated DRBIO port Post reply
	> It would be useful to change some instructions "LEA Dst,Addr" to the > shorter "MOV Dst,OFFSET Addr" Yes, I can give you access to the repo at https://github.com/SvarDOS/edrdos

ecm

Düsseldorf, Germany,
23.07.2024, 21:34

@ CandyMan

EDR-DOS kernel ported to JWasm - ident86 validated DRBIO port

Post reply

> It would be useful to change some instructions "LEA Dst,Addr" to the
> shorter "MOV Dst,OFFSET Addr"

Apparently this is done by some version of MASM, but JWasm doesn't do it.

---
l

Rugxulo

Usono,
24.07.2024, 00:25

@ ecm

EDR-DOS kernel ported to JWasm - ident86 validated DRBIO port

Post reply

> > It would be useful to change some instructions "LEA Dst,Addr" to the
> > shorter "MOV Dst,OFFSET Addr"
>
> Apparently this is done by some version of MASM, but JWasm doesn't do it.

TASM and A86 do it by default, but newer MASMs (since v5?) don't do it anymore. Some purists complain when an assembler does things "behind your back".

IIRC, the recommended fix is via a macro with opattr 8 (or such). You probably have to use "option nokeyword:<lea>" first if you insist on calling the macro LEA.

It only saves a byte per instance and probably isn't noticeably faster.

> MASM 6.11 README.TXT
> The MASM 6.1 Reference indicates that the LEA instruction is
> encoded as a MOV when the source operand is a direct memory address.
>
> In response to programmer requests, MASM 6.1x no longer performs this
> optimization automatically. The optimization can be performed by
> using the OPATTR operator, as shown in the following macro:
MOVLEA MACRO Dest, Symbol IF (OPATTR(Symbol)) AND 08h MOV Dest, OFFSET Symbol ELSE LEA Dest, Symbol ENDIF ENDM

CandyMan 08.06.2024, 09:59 @ ecm	Enhanced DR-DOS - CD bug Post reply
	> The next changeset will fix this problem, please test today's June build in > 45min from now. Version 20240607 works fine. Could you create an alternative version of EDR-DOS and add detection of FAT drives on the GPT partition? See how this is done in FreeDOS. Thanks. InitDisk.C (FreeDOS) https://megawrzuta.pl/download/078fe0c107fb750fb2f9120126d869e5.html

boeckmann

Aachen, Germany,
20.06.2024, 18:00

@ CandyMan

Enhanced DR-DOS - CD bug

Post reply

> Could you create an alternative version of EDR-DOS and add detection of FAT
> drives on the GPT partition? See how this is done in FreeDOS.

There are also a bunch of incompatibilities between FreeDOS / MS-DOS and EDR kernels regarding drive letter assignment
https://github.com/SvarDOS/edrdos/issues/59

and the permitted access to non-initialized FAT partitions
https://github.com/SvarDOS/edrdos/issues/15

If anyone is interested in working on this, feel free to join...

boeckmann Aachen, Germany, 30.06.2024, 16:57 @ boeckmann	Enhanced DR-DOS - CD bug Post reply
	The DRBIO.SYS source is now fully ported to JWasm and can also be build under Win32 (and probably Linux if OpenWatcom WLINK is installed). Porting DRDOS.SYS will take some time. But after that the EDR-DOS kernel should be buildable with free software.

CandyMan 19.06.2024, 19:45 @ ecm	? Post reply
	?

glennmcc

North Jackson, Ohio (USA),
22.06.2024, 02:13

@ CandyMan

?

Post reply

> ?

What is your question ? ;-)

---
--
http://glennmcc.org/

nico7550 23.06.2024, 08:18 @ glennmcc	? Post reply
	> > ? > > What is your question ? His question is is in the post just above the interrogation point post

CandyMan 03.07.2024, 17:55 @ glennmcc	unnecessary "stc" Post reply
	"STC" instructions are unnecessary in "dos7.asm" if there is a jump to error_exit() where the flags are changed and the interrupt is exited with the CF flag set. `stc jmp error_exit ; no, then exit with error`

Enhanced DR-DOS single-file load (2023 December revision) (Announce)

Enhanced DR-DOS single-file load (2023 December revision)

Enhanced DR-DOS single-file load (2023 December revision)

Enhanced DR-DOS single-file load (2023 December revision)

Enhanced DR-DOS development

lDebug boot loading other kernels

Enhanced DR-DOS single-file load (2023 December revision)

Enhanced DR-DOS single-file load (2023 December revision)

Enhanced DR-DOS single-file load (2023 December revision)

Enhanced DR-DOS - CD bug

Enhanced DR-DOS - CD bug

Enhanced DR-DOS - CD bug

Enhanced DR-DOS - CD bug

Enhanced DR-DOS - CD bug

FAT32 search on GPT partition

FAT32 search on GPT partition

FAT32 search on GPT partition

FAT32 search on GPT partition

Kernel ported to JWasm

Kernel ported to JWasm

Kernel ported to JWasm

EDR-DOS kernel ported to JWasm - ident86 validated DRBIO port

EDR-DOS kernel ported to JWasm - ident86 validated DRBIO port

EDR-DOS kernel ported to JWasm - ident86 validated DRBIO port

EDR-DOS kernel ported to JWasm - ident86 validated DRBIO port

EDR-DOS kernel ported to JWasm - ident86 validated DRBIO port

EDR-DOS kernel ported to JWasm - ident86 validated DRBIO port

Enhanced DR-DOS - CD bug

Enhanced DR-DOS - CD bug

Enhanced DR-DOS - CD bug

?

?

?

unnecessary "stc"