Interesting Tests We Could Run For x86

[jordi]

I've found some interesting tests that were linked from vogons for verifying x86 CPu
https://forum.osdev.org/viewtopic.php?f ... 9&start=15

I guess it's just a matter of compiling them

[jordi]

https://www.vogons.org/viewtopic.php?t=73677

This was the original topic at vogons

[MicroCoreLabs]

Here are the tests I wrote to verify the MCL86 core which touch on the opcodes, addressing modes, and flags.

https://github.com/MicroCoreLabs/Projec ... CL86/Tests

It compiles using A86 into .COM files which run under DOS. I'm sure they are not 100% exhaustive but were good enough to verify the core to a large degree.

Source code is simple and can easily be extended. Upon failure it prints a character using a DOS call so you can track it down in the test source code.

[Mills]

I've found some interesting tests that were linked from vogons for verifying x86 CPu
https://forum.osdev.org/viewtopic.php?f ... 9&start=15

I guess it's just a matter of compiling them

I compiled that, they had some errors (relative jump instructions out of range for 8088/86) I think I solved that, there are some "failed" text but I think that's my fault.

It looks like they did not fail until the program gets stuck, probably because the code is incomplete and they need some kind of "end " instruction.

CPUTEST.zip

(4.17 KiB) Downloaded 175 times

[Mills]

Here are the tests I wrote to verify the MCL86 core which touch on the opcodes, addressing modes, and flags.

https://github.com/MicroCoreLabs/Projec ... CL86/Tests

It compiles using A86 into .COM files which run under DOS. I'm sure they are not 100% exhaustive but were good enough to verify the core to a large degree.

Source code is simple and can easily be extended. Upon failure it prints a character using a DOS call so you can track it down in the test source code.

It looks like PCXT passed all that tests , this is how it looks like after running "runall.bat":

20220923_154459-screen.png (68.9 KiB) Viewed 5146 times

[MicroCoreLabs]

It looks like PCXT passed all that tests , this is how it looks like after running "runall.bat":

Yes, this was the desired result!

I wrote all of these tests on a genuine IBM PCXT using QEdit and then ran them on a PC which had an MCL86 installed. For opcodes which failed I single-stepped the same test on both computers using D86 to see where they diverged.

If I recall correctly, the online emulator PCJs would not complete these tests successfully...

[thorr]

Awesome stuff!

[pgimeno]

Is the segment override bug now incorporated as a regression test? It's customary practice to add a test that fails before a bugfix and passes after it, every time a bug is squashed. That's where regression tests take their name, after all: if the bug returns, that's a regression and it will be immediately caught by the test. Some bugs have the bad habit of reviving some time after being squashed.

Best practices also dictate to search for patterns similar to the one that produced the bug, and to elaborate tests that also exercise them. Chances are that if a bug is detected, and there's more code similar to the one that triggered the bug, it will also be similarly bugged. In this case, all segment combinations with all string instruction combinations should probably be exercised by tests, with and without repetition.

[MicroCoreLabs]

These are all good points but I will leave it as a project for someone else.

[MicroCoreLabs]

Has anyone tried Area5150 with all of the bug fixes and upgrades recently?

[spark2k06]

Has anyone tried Area5150 with all of the bug fixes and upgrades recently?

Area5150 still has some bugs, but I don't think they are CPU related. Rather, they are bugs related to the CGA implementation, and perhaps a few with timings.

On the other hand, I have to debug a couple of bugs in games... and at least one of them (Bubble Bobble) I'm sure it's timings or something related to the timer.

[kitune-san]

Has anyone tried Area5150 with all of the bug fixes and upgrades recently?

Area5150 still has some bugs, but I don't think they are CPU related. Rather, they are bugs related to the CGA implementation, and perhaps a few with timings.

On the other hand, I have to debug a couple of bugs in games... and at least one of them (Bubble Bobble) I'm sure it's timings or something related to the timer.

Please tell me if you notice anything that I can do to help you.

In area 5150, there are two scenes that slow down.
I assume that many instructions are used which have different number of clocks depending on the source.
For example, DIV or MUL instructions. As I recall, in MCL86, the number of clocks consumed by these instructions is fixed.
However, I have not seen the source code, so this assumption may be incorrect.

[spark2k06]

Please tell me if you notice anything that I can do to help you.

In area 5150, there are two scenes that slow down.
I assume that many instructions are used which have different number of clocks depending on the source.
For example, DIV or MUL instructions. As I recall, in MCL86, the number of clocks consumed by these instructions is fixed.
However, I have not seen the source code, so this assumption may be incorrect.

Yes, I'll let you know, thank you!

I'm closing an issue related to the screen borders and I'll start debugging Bubble Bobble shortly, as for this one I don't think we'll ever get the source code.

Regarding area5150, I'm not going to dedicate more effort to it until I have the source code, because I think it will be released sooner or later.

[thorr]

Thanks for your efforts guys. When you get a chance, if either of you have CRT TV's, it would be great if you could work on stabilizing the CRT TV compatibility/modelines to work on more displays. I don't know if they are already correct compared to real hardware, or if work can be done to improve the situation. I don't know if the latest HDMI fixes also fix this problem. It's possible. I can't test at the moment with my paint fume filled room.

[kitune-san]

Thanks for your efforts guys. When you get a chance, if either of you have CRT TV's, it would be great if you could work on stabilizing the CRT TV compatibility/modelines to work on more displays. I don't know if they are already correct compared to real hardware, or if work can be done to improve the situation. I don't know if the latest HDMI fixes also fix this problem. It's possible. I can't test at the moment with my paint fume filled room.

Sorry. I don't have a CRT monitor or a 15 kHz monitor. Also, I am not familiar with video modules.
Perhaps only @spark2k06 can solve this issue.

[spark2k06]

Thanks for your efforts guys. When you get a chance, if either of you have CRT TV's, it would be great if you could work on stabilizing the CRT TV compatibility/modelines to work on more displays. I don't know if they are already correct compared to real hardware, or if work can be done to improve the situation. I don't know if the latest HDMI fixes also fix this problem. It's possible. I can't test at the moment with my paint fume filled room.

Sorry, I don't have a CRT monitor either, just wait for other developers to show interest in this core.

[kitune-san]

On the other hand, I have to debug a couple of bugs in games... and at least one of them (Bubble Bobble) I'm sure it's timings or something related to the timer.

Maybe there is a bug in the Timer output in mode 3.

[suverman]

Asteroid Pilot:

Basica based game (speed sensitive, run well on PCXT class machines)
https://www.youtube.com/watch?v=6a09BmsHjzA

This does not run on the PCXT core. Seems like Basic uses a method of accessing disk which is not currently supported? Not sure.

[breiztiger]

it's basica that doesn't start

[suverman]

it's basica that doesn't start

Sorry if this was a known issue.

[kitune-san]

On the other hand, I have to debug a couple of bugs in games... and at least one of them (Bubble Bobble) I'm sure it's timings or something related to the timer.

Maybe there is a bug in the Timer output in mode 3.

Fixed timer. Pls try it.

[spark2k06]

Maybe there is a bug in the Timer output in mode 3.

This is what I have found out so far. The routine in charge of triggering the start-up music is as follows:

Code: Select all

seg000:F945                               sub_1F945       proc near               ; CODE XREF: seg000:loc_1F907p
seg000:F945 32 E4                                         xor     ah, ah
seg000:F947 BD 00 00                                      mov     bp, 0
seg000:F94A 8B C8                                         mov     cx, ax
seg000:F94C FA                                            cli
seg000:F94D 8E 06 14 01                                   mov     es, word ptr ds:114h
seg000:F951 26 8B 5E 00                                   mov     bx, es:[bp+0]
seg000:F955 3B CB                                         cmp     cx, bx
seg000:F957 73 71                                         jnb     short loc_1F9CA
seg000:F959 41                                            inc     cx
seg000:F95A D1 E1                                         shl     cx, 1
seg000:F95C 8B E9                                         mov     bp, cx
seg000:F95E 26 8B 6E 00                                   mov     bp, es:[bp+0]
seg000:F962 0B ED                                         or      bp, bp
seg000:F964 74 64                                         jz      short loc_1F9CA
seg000:F966 89 2E 16 01                                   mov     ds:116h, bp
seg000:F96A 26 8B 5E 08                                   mov     bx, es:[bp+8]
seg000:F96E 89 1E 20 01                                   mov     ds:120h, bx
seg000:F972 26 8B 5E 04                                   mov     bx, es:[bp+4]
seg000:F976 89 1E 1A 01                                   mov     ds:11Ah, bx
seg000:F97A 26 8B 5E 02                                   mov     bx, es:[bp+2]
seg000:F97E 89 1E 18 01                                   mov     ds:118h, bx
seg000:F982 8B D5                                         mov     dx, bp
seg000:F984 8B EB                                         mov     bp, bx
seg000:F986 8B 36 0E 03                                   mov     si, ds:30Eh
seg000:F98A BF 00 00                                      mov     di, 0
seg000:F98D 8B 0E 3C 00                                   mov     cx, ds:3Ch
seg000:F991 8B D8                                         mov     bx, ax
seg000:F993 83 F9 02                                      cmp     cx, 2
seg000:F996 75 01                                         jnz     short loc_1F999
seg000:F998 49                                            dec     cx
seg000:F999
seg000:F999                               loc_1F999:                              ; CODE XREF: sub_1F945+51j
seg000:F999                                                                       ; sub_1F945+7Aj
seg000:F999 26 8B 03                                      mov     ax, es:[bp+di]
seg000:F99C 0B C0                                         or      ax, ax
seg000:F99E 74 19                                         jz      short loc_1F9B9
seg000:F9A0 89 84 58 01                                   mov     [si+158h], ax
seg000:F9A4 89 84 6A 01                                   mov     [si+16Ah], ax
seg000:F9A8 C7 84 22 01 01 00                             mov     word ptr [si+122h], 1
seg000:F9AE 89 9C 8E 01                                   mov     [si+18Eh], bx
seg000:F9B2 A1 1A 01                                      mov     ax, ds:11Ah
seg000:F9B5 89 84 A0 01                                   mov     [si+1A0h], ax
seg000:F9B9
seg000:F9B9                               loc_1F9B9:                              ; CODE XREF: sub_1F945+59j
seg000:F9B9 83 C6 02                                      add     si, 2
seg000:F9BC 83 C7 02                                      add     di, 2
seg000:F9BF E2 D8                                         loop    loc_1F999
seg000:F9C1 8B EA                                         mov     bp, dx
seg000:F9C3 26 8B 46 0A                                   mov     ax, es:[bp+0Ah]
seg000:F9C7 0B D2                                         or      dx, dx
seg000:F9C9 C3                                            retn
seg000:F9CA                               ; ---------------------------------------------------------------------------
seg000:F9CA
seg000:F9CA                               loc_1F9CA:                              ; CODE XREF: sub_1F945+12j
seg000:F9CA                                                                       ; sub_1F945+1Fj
seg000:F9CA B8 00 00                                      mov     ax, 0
seg000:F9CD 0B C0                                         or      ax, ax
seg000:F9CF C3                                            retn
seg000:F9CF                               sub_1F945       endp

And the music is in the background. This routine seems to activate sequences of music that are repeated in a loop... until they are all there. From what I've seen, he has modified the interrupt table to replace the timer routine, with the following code:

Code: Select all

seg000:08C2                               ; ---------------------------------------------------------------------------
seg000:08C2 50                                            push    ax
seg000:08C3 53                                            push    bx
seg000:08C4 51                                            push    cx
seg000:08C5 52                                            push    dx
seg000:08C6 1E                                            push    ds
seg000:08C7 55                                            push    bp
seg000:08C8 56                                            push    si
seg000:08C9 57                                            push    di
seg000:08CA 06                                            push    es
seg000:08CB B8 C1 31                                      mov     ax, 31C1h
seg000:08CE 8E D8                                         mov     ds, ax
seg000:08D0 D0 0E 2C 01                                   ror     byte ptr ds:12Ch, 1
seg000:08D4 F7 06 30 01 FF FF                             test    word ptr ds:130h, 0FFFFh
seg000:08DA 75 54                                         jnz     short loc_10930
seg000:08DC B8 40 00                                      mov     ax, 40h ; '@'
seg000:08DF 8E C0                                         mov     es, ax
seg000:08E1 26 8B 16 63 00                                mov     dx, es:63h
seg000:08E6 80 C2 06                                      add     dl, 6
seg000:08E9 B9 2C 01                                      mov     cx, 12Ch
seg000:08EC
seg000:08EC                               loc_108EC:                              ; CODE XREF: seg000:08EFj
seg000:08EC EC                                            in      al, dx
seg000:08ED 24 08                                         and     al, 8
seg000:08EF E1 FB                                         loope   loc_108EC
seg000:08F1 B0 36                                         mov     al, 36h ; '6'
seg000:08F3 E6 43                                         out     43h, al         ; Timer 8253-5 (AT: 8254.2).
seg000:08F5 A0 1A 01                                      mov     al, ds:11Ah
seg000:08F8 E6 40                                         out     40h, al         ; Timer 8253-5 (AT: 8254.2).
seg000:08FA A0 1B 01                                      mov     al, ds:11Bh
seg000:08FD E6 40                                         out     40h, al         ; Timer 8253-5 (AT: 8254.2).
seg000:08FF E3 2F                                         jcxz    short loc_10930
seg000:0901 81 F9 13 01                                   cmp     cx, 113h
seg000:0905 72 05                                         jb      short loc_1090C
seg000:0907 83 2E 1A 01 0A                                sub     word ptr ds:11Ah, 0Ah
seg000:090C
seg000:090C                               loc_1090C:                              ; CODE XREF: seg000:0905j
seg000:090C 81 F9 E1 00                                   cmp     cx, 0E1h ; 'ß'
seg000:0910 77 0C                                         ja      short loc_1091E
seg000:0912 A1 2E 01                                      mov     ax, ds:12Eh
seg000:0915 2B C1                                         sub     ax, cx
seg000:0917 78 05                                         js      short loc_1091E
seg000:0919 83 06 1A 01 02                                add     word ptr ds:11Ah, 2
seg000:091E
seg000:091E                               loc_1091E:                              ; CODE XREF: seg000:0910j
seg000:091E                                                                       ; seg000:0917j
seg000:091E 89 0E 2E 01                                   mov     ds:12Eh, cx
seg000:0922 8B C1                                         mov     ax, cx
seg000:0924 FF 1E 96 00                                   call    dword ptr ds:96h
seg000:0928 FF 06 24 01                                   inc     word ptr ds:124h
seg000:092C D1 2E 26 01                                   shr     word ptr ds:126h, 1
seg000:0930
seg000:0930                               loc_10930:                              ; CODE XREF: seg000:08DAj
seg000:0930                                                                       ; seg000:08FFj
seg000:0930 FB                                            sti
seg000:0931 A1 08 01                                      mov     ax, ds:108h
seg000:0934 01 06 06 01                                   add     ds:106h, ax
seg000:0938 73 0C                                         jnb     short loc_10946
seg000:093A FF 06 1E 01                                   inc     word ptr ds:11Eh
seg000:093E D1 2E 20 01                                   shr     word ptr ds:120h, 1
seg000:0942 FF 2E 02 01                                   jmp     dword ptr ds:102h
seg000:0946                               ; ---------------------------------------------------------------------------
seg000:0946
seg000:0946                               loc_10946:                              ; CODE XREF: seg000:0938j
seg000:0946 A1 10 01                                      mov     ax, ds:110h
seg000:0949 01 06 0E 01                                   add     ds:10Eh, ax
seg000:094D 73 04                                         jnb     short loc_10953
seg000:094F FF 2E 0A 01                                   jmp     dword ptr ds:10Ah
seg000:0953                               ; ---------------------------------------------------------------------------
seg000:0953
seg000:0953                               loc_10953:                              ; CODE XREF: seg000:094Dj
seg000:0953 A1 14 01                                      mov     ax, ds:114h
seg000:0956 01 06 12 01                                   add     ds:112h, ax
seg000:095A 72 0E                                         jb      short loc_1096A
seg000:095C B0 20                                         mov     al, 20h ; ' '
seg000:095E E6 20                                         out     20h, al         ; Interrupt controller, 8259A.
seg000:0960 07                                            pop     es
seg000:0961                                               assume es:nothing
seg000:0961 5F                                            pop     di
seg000:0962 5E                                            pop     si
seg000:0963 5D                                            pop     bp
seg000:0964 1F                                            pop     ds
seg000:0965                                               assume ds:nothing
seg000:0965 5A                                            pop     dx
seg000:0966 59                                            pop     cx
seg000:0967 5B                                            pop     bx
seg000:0968 58                                            pop     ax
seg000:0969 CF                                            iret
seg000:096A                               ; ---------------------------------------------------------------------------
seg000:096A
seg000:096A                               loc_1096A:                              ; CODE XREF: seg000:095Aj
seg000:096A 07                                            pop     es
seg000:096B 5F                                            pop     di
seg000:096C 5E                                            pop     si
seg000:096D 5D                                            pop     bp
seg000:096E 1F                                            pop     ds
seg000:096F 5A                                            pop     dx
seg000:0970 59                                            pop     cx
seg000:0971 5B                                            pop     bx
seg000:0972 58                                            pop     ax
seg000:0973 FA                                            cli
seg000:0974 2E FF 2E 7A 09                                jmp     cs:dword_1097A
seg000:0974                               ; ---------------------------------------------------------------------------
seg000:0979 90                                            db  90h ; É
seg000:097A 3C 00 23 15                   dword_1097A     dd 1523003Ch            ; DATA XREF: sub_1072C+5w
seg000:097A                                                                       ; sub_107A6r ...

The last part of this code is intended to continue the original timer routine:

Code: Select all

seg000:0973 FA                                            cli
seg000:0974 2E FF 2E 7A 09                                jmp     cs:dword_1097A
seg000:0974                               ; ---------------------------------------------------------------------------
seg000:0979 90                                            db  90h ; É
seg000:097A 3C 00 23 15                   dword_1097A     dd 1523003Ch            ; DATA XREF: sub_1072C+5w
seg000:097A                                                                       ; sub_107A6r ...

I don't know if it will help you at all, but if I find out more or narrow down the exact problem I'll let you know.

[kitune-san]

Code: Select all

seg000:08F1 B0 36                                         mov     al, 36h ; '6'
seg000:08F3 E6 43                                         out     43h, al         ; Timer 8253-5 (AT: 8254.2).
seg000:08F5 A0 1A 01                                      mov     al, ds:11Ah
seg000:08F8 E6 40                                         out     40h, al         ; Timer 8253-5 (AT: 8254.2).
seg000:08FA A0 1B 01                                      mov     al, ds:11Bh
seg000:08FD E6 40                                         out     40h, al         ; Timer 8253-5 (AT: 8254.2).

I think this modification will work because it is set to mode 3.

[spark2k06]

Code: Select all

seg000:08F1 B0 36                                         mov     al, 36h ; '6'
seg000:08F3 E6 43                                         out     43h, al         ; Timer 8253-5 (AT: 8254.2).
seg000:08F5 A0 1A 01                                      mov     al, ds:11Ah
seg000:08F8 E6 40                                         out     40h, al         ; Timer 8253-5 (AT: 8254.2).
seg000:08FA A0 1B 01                                      mov     al, ds:11Bh
seg000:08FD E6 40                                         out     40h, al         ; Timer 8253-5 (AT: 8254.2).

I think this modification will work because it is set to mode 3.

These routines, they work... but the music sounds too fast in the core, when in a real PCXT the speed is correct.

Edit: Wait, I didn't see that you sent a new binary, I'll try it right now

[spark2k06]

On the other hand, I have to debug a couple of bugs in games... and at least one of them (Bubble Bobble) I'm sure it's timings or something related to the timer.

Maybe there is a bug in the Timer output in mode 3.

Fixed timer. Pls try it.

It's working! Thanks... let's try the demos now

[kitune-san]

I sent pull request.