5 ms·

Wozmon for x86-64

60 points by ianseyler 3y ago

bArray 3y ago
Very cool. When it mentions a bare metal kernel, I thought about the BareMetal OS by ReturnInfinity: https://github.com/ReturnInfinity/BareMetal-OS https://github.com/ReturnInfinity/BareMetal-OS
- ianseyler 3y ago
  Yes - it uses the BareMetal OS kernel. I also wrote that.
vbitz 3y ago
Awesome. Nice and easy to get working as well.
rendaw 3y ago
I have this image of you spending years painstakingly rewriting this, just for Apple to release their ARM processors. FWIW I have no idea what Wozmon is, just a sentence or two at the top for people not familiar with the original.
- selcuka 3y ago
  > I have this image of you spending years painstakingly rewriting this Initial commit: 5 days ago
k8svet 3y ago
Read the readme, consider myself a mostly-not-total-idiot. Would buy author a beer to add a whole two sentences to illuminate what wozman is. If it's just that niche and I'm ignorant feel free to ignore me.
- RossBencina 3y ago
  The source code[1] has a better intro: > A complete instruction by instruction rewrite of Steve Wozniak's system monitor from 1976 for the Apple-1 I found a nice intro to Wozmon here: https://www.sbprojects.net/projects/apple1/wozmon.php https://www.sbprojects.net/projects/apple1/wozmon.php To add to your suggestion for the README: if this is indeed an "instruction by instruction rewrite" then it would also be helpful to include a canonical link to the original 6502 source. (Found a version here: https://gist.github.com/nobuh/1161983 https://gist.github.com/nobuh/1161983) [1] https://github.com/IanSeyler/wozmon_x86-64/blob/main/src/wozmon.asm https://github.com/IanSeyler/wozmon_x86-64/blob/main/src/woz...
- reanimus 3y ago
  It's the boot ROM that came with the Apple I. It was pretty big for the time given that in those days, computers didn't come with flash, so you had to bootstrap programs with dip switches and the like. The Apple I came with wozmon on ROM, which provided a (VERY) minimal prompt to edit/view memory and run programs from it.
  - coldpie 3y ago
    > so you had to bootstrap programs with dip switches and the like For more on this, check out this amazing series of videos from deramp5113 about the Altair 8800: https://www.youtube.com/playlist?list=PLB3mwSROoJ4KLWM8KwK0cD1dhX35wILBj https://www.youtube.com/playlist?list=PLB3mwSROoJ4KLWM8KwK0c... (Also available on archive.org: https://archive.org/search?query=altair+8800&sort=title&and%5B%5D=creator%3A%22mike+douglas%22 https://archive.org/search?query=altair+8800&sort=title&and%... )
- zellyn 3y ago
  This might be helpful… https://www.youtube.com/watch?v=SpG8rgI7Hec https://www.youtube.com/watch?v=SpG8rgI7Hec I find it a little weird that these comments always come up on hackernews… if you type "wozmon" in your URL bar and hit enter to search, pretty much _all_ the results are pertinent and helpful.
  - fragmede 3y ago
    [dead]
- helsinkiandrew 3y ago
  Ben Eater has a number of very informative videos on Wozmon on YouTube - what it is, how it works and and getting it to work on a home built 6502 machine, literally stepping through the assembly: Running Apple 1 software on a breadboard computer (Wozmon) https://www.youtube.com/watch?v=HlLCtjJzHVI https://www.youtube.com/watch?v=HlLCtjJzHVI How Wozniak’s code for the Apple 1 works: https://www.youtube.com/watch?v=SpG8rgI7Hec https://www.youtube.com/watch?v=SpG8rgI7Hec Adapting WozMon for the breadboard 6502 https://www.youtube.com/watch?v=7M8LvMtdcgY https://www.youtube.com/watch?v=7M8LvMtdcgY
- benj111 3y ago
  It's a monitor by Steve (woz)niak. Self explanatory really!
- ianseyler 3y ago
  Good point! I've added some text about wozmon to the README.
DeathArrow 3y ago
I understand what this is. What I don't understand is what is the purpose of doing it.
- creatonez 3y ago
  It is wildly impractical to not have an OS and have to manually program your computer every time you boot it. But don't you want to try it?
  - atcalan 3y ago
    That depends. Do you want to avoid the Thompson back door? Maybe a 6502 or an 1802 with flippety switches and blinken lights can be verified not to be compromised.
    - atcalan 3y ago
      https://wiki.c2.com/?TheKenThompsonHack https://wiki.c2.com/?TheKenThompsonHack
- 082349872349872 3y ago
  Having a monitor is easier than constantly reflashing for every little change. (back in the days of EPROMs, much easier)
- justarobert 3y ago
  fun?
  - ianseyler 3y ago
    That was the primary reason - a fun weekend project converting 6502 Assembly to x86-64 line by line. The x86-64 version comes in at a 384-byte binary due to instructions being a bit longer.
danbruc 3y ago
wozmon.sh run will start Wozmon in a QEMU virtual machine. Does it also run without the virtual machine?
- hsnewman 3y ago
  Why would it not?
  - danbruc 3y ago
    Should have been more specific, can I run it on Linux or Windows and mess with the memory content? So why not? Because of dependencies on BareMetal or having to overcome the isolation build into the operating system it runs on top of.
- creatonez 3y ago
  From the author's BareMetal exokernel repository: > Key features > [...] > Physical and virtual hardware support with full virtualization, using x86 hardware virtualization whenever available (it is on most modern x86-64 CPU's). In principle BareMetal should run on any x86-64 hardware platform, even on a physical x86-64 computer, given appropriate drivers. Officially, we develop on QEMU and VirtualBox, which means that you can run BareMetal on both Linux, Microsoft Windows, and Apple macOS. There's no indication of specific real-world testing, though.
gabrielsroka 3y ago
What a coincidence. I recently converted the 6502 version to Python and then worked with ChatGPT to convert the Python to C. (I'm not a C programmer.) https://github.com/gabrielsroka/gabrielsroka.github.io/tree/master/wozmon https://github.com/gabrielsroka/gabrielsroka.github.io/tree/...
- asveikau 3y ago
  To support running code you'll need to call mprotect(2) on the buffer to make it executable. If you hit Ctrl-d on this code it will burn through that loop constantly with no input. You need to check fgets()'s return code, it will be NULL on error or eof.
  - gabrielsroka 3y ago
    Thank you. I saw a warning about that from the compiler. But like I said I'm not a C programmer. Feel free to submit a PR if you like. I assume you're talking about Linux/Unix. I'm mostly a Windows guy.
    - asveikau 3y ago
      I am knowledgeable about both. Unix guy at heart but used to work for MSFT on windows. The Windows version of mprotect(2) is VirtualProtect. It would probably make more sense to allocate the buffer with VirtualAlloc with the correct flags, rather than modify a stack buffer. The Unix version of that would be to allocate with mmap(2). Edit: https://github.com/gabrielsroka/gabrielsroka.github.io/pull/62 https://github.com/gabrielsroka/gabrielsroka.github.io/pull/...
- ianseyler 3y ago
  Interesting to see it written in higher-level languages!
atcalan 3y ago
I remember vapor locking on figuring out addresses in hand assembled 6809 machine code in middle school. It was amazing what Woz pulled off with this. I wish I knew that the apple ii plusses in the computer lab probably had something like wozmon on them.

60 points by ianseyler 3y ago

Very cool. When it mentions a bare metal kernel, I thought about the BareMetal OS by ReturnInfinity: https://github.com/ReturnInfinity/BareMetal-OS https://github.com/ReturnInfinity/BareMetal-OS

ianseyler 3y ago
Yes - it uses the BareMetal OS kernel. I also wrote that.

vbitz 3y ago

Awesome. Nice and easy to get working as well.

rendaw 3y ago

I have this image of you spending years painstakingly rewriting this, just for Apple to release their ARM processors. FWIW I have no idea what Wozmon is, just a sentence or two at the top for people not familiar with the original.

selcuka 3y ago
> I have this image of you spending years painstakingly rewriting this Initial commit: 5 days ago

k8svet 3y ago

Read the readme, consider myself a mostly-not-total-idiot. Would buy author a beer to add a whole two sentences to illuminate what wozman is. If it's just that niche and I'm ignorant feel free to ignore me.

RossBencina 3y ago
The source code[1] has a better intro: > A complete instruction by instruction rewrite of Steve Wozniak's system monitor from 1976 for the Apple-1 I found a nice intro to Wozmon here: https://www.sbprojects.net/projects/apple1/wozmon.php https://www.sbprojects.net/projects/apple1/wozmon.php To add to your suggestion for the README: if this is indeed an "instruction by instruction rewrite" then it would also be helpful to include a canonical link to the original 6502 source. (Found a version here: https://gist.github.com/nobuh/1161983 https://gist.github.com/nobuh/1161983) [1] https://github.com/IanSeyler/wozmon_x86-64/blob/main/src/wozmon.asm https://github.com/IanSeyler/wozmon_x86-64/blob/main/src/woz...
reanimus 3y ago
It's the boot ROM that came with the Apple I. It was pretty big for the time given that in those days, computers didn't come with flash, so you had to bootstrap programs with dip switches and the like. The Apple I came with wozmon on ROM, which provided a (VERY) minimal prompt to edit/view memory and run programs from it.
- coldpie 3y ago
  > so you had to bootstrap programs with dip switches and the like For more on this, check out this amazing series of videos from deramp5113 about the Altair 8800: https://www.youtube.com/playlist?list=PLB3mwSROoJ4KLWM8KwK0cD1dhX35wILBj https://www.youtube.com/playlist?list=PLB3mwSROoJ4KLWM8KwK0c... (Also available on archive.org: https://archive.org/search?query=altair+8800&sort=title&and%5B%5D=creator%3A%22mike+douglas%22 https://archive.org/search?query=altair+8800&sort=title&and%... )
zellyn 3y ago
This might be helpful… https://www.youtube.com/watch?v=SpG8rgI7Hec https://www.youtube.com/watch?v=SpG8rgI7Hec I find it a little weird that these comments always come up on hackernews… if you type "wozmon" in your URL bar and hit enter to search, pretty much _all_ the results are pertinent and helpful.
- fragmede 3y ago
  [dead]
helsinkiandrew 3y ago
Ben Eater has a number of very informative videos on Wozmon on YouTube - what it is, how it works and and getting it to work on a home built 6502 machine, literally stepping through the assembly: Running Apple 1 software on a breadboard computer (Wozmon) https://www.youtube.com/watch?v=HlLCtjJzHVI https://www.youtube.com/watch?v=HlLCtjJzHVI How Wozniak’s code for the Apple 1 works: https://www.youtube.com/watch?v=SpG8rgI7Hec https://www.youtube.com/watch?v=SpG8rgI7Hec Adapting WozMon for the breadboard 6502 https://www.youtube.com/watch?v=7M8LvMtdcgY https://www.youtube.com/watch?v=7M8LvMtdcgY
benj111 3y ago
It's a monitor by Steve (woz)niak. Self explanatory really!
ianseyler 3y ago
Good point! I've added some text about wozmon to the README.

DeathArrow 3y ago

I understand what this is. What I don't understand is what is the purpose of doing it.

creatonez 3y ago
It is wildly impractical to not have an OS and have to manually program your computer every time you boot it. But don't you want to try it?
- atcalan 3y ago
  That depends. Do you want to avoid the Thompson back door? Maybe a 6502 or an 1802 with flippety switches and blinken lights can be verified not to be compromised.
  - atcalan 3y ago
    https://wiki.c2.com/?TheKenThompsonHack https://wiki.c2.com/?TheKenThompsonHack
082349872349872 3y ago
Having a monitor is easier than constantly reflashing for every little change. (back in the days of EPROMs, much easier)
justarobert 3y ago
fun?
- ianseyler 3y ago
  That was the primary reason - a fun weekend project converting 6502 Assembly to x86-64 line by line. The x86-64 version comes in at a 384-byte binary due to instructions being a bit longer.

danbruc 3y ago

wozmon.sh run will start Wozmon in a QEMU virtual machine. Does it also run without the virtual machine?

hsnewman 3y ago
Why would it not?
- danbruc 3y ago
  Should have been more specific, can I run it on Linux or Windows and mess with the memory content? So why not? Because of dependencies on BareMetal or having to overcome the isolation build into the operating system it runs on top of.
creatonez 3y ago
From the author's BareMetal exokernel repository: > Key features > [...] > Physical and virtual hardware support with full virtualization, using x86 hardware virtualization whenever available (it is on most modern x86-64 CPU's). In principle BareMetal should run on any x86-64 hardware platform, even on a physical x86-64 computer, given appropriate drivers. Officially, we develop on QEMU and VirtualBox, which means that you can run BareMetal on both Linux, Microsoft Windows, and Apple macOS. There's no indication of specific real-world testing, though.

gabrielsroka 3y ago

What a coincidence. I recently converted the 6502 version to Python and then worked with ChatGPT to convert the Python to C. (I'm not a C programmer.) https://github.com/gabrielsroka/gabrielsroka.github.io/tree/master/wozmon https://github.com/gabrielsroka/gabrielsroka.github.io/tree/...

asveikau 3y ago
To support running code you'll need to call mprotect(2) on the buffer to make it executable. If you hit Ctrl-d on this code it will burn through that loop constantly with no input. You need to check fgets()'s return code, it will be NULL on error or eof.
- gabrielsroka 3y ago
  Thank you. I saw a warning about that from the compiler. But like I said I'm not a C programmer. Feel free to submit a PR if you like. I assume you're talking about Linux/Unix. I'm mostly a Windows guy.
  - asveikau 3y ago
    I am knowledgeable about both. Unix guy at heart but used to work for MSFT on windows. The Windows version of mprotect(2) is VirtualProtect. It would probably make more sense to allocate the buffer with VirtualAlloc with the correct flags, rather than modify a stack buffer. The Unix version of that would be to allocate with mmap(2). Edit: https://github.com/gabrielsroka/gabrielsroka.github.io/pull/62 https://github.com/gabrielsroka/gabrielsroka.github.io/pull/...
ianseyler 3y ago
Interesting to see it written in higher-level languages!

atcalan 3y ago

I remember vapor locking on figuring out addresses in hand assembled 6809 machine code in middle school. It was amazing what Woz pulled off with this. I wish I knew that the apple ii plusses in the computer lab probably had something like wozmon on them.