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<roconnor> https://github.com/oriansj/stage0-posix/blob/master/makefile#L147 does test-all work? I thought each test requires it be run on a different architecture.

<muurkha>oh hi roconnor, glad to see you here! this is Kragen

<roconnor>Hey Kragen.

<muurkha>unfortunately I don't know the answer to your question

<roconnor>I've been playing with stage0-posix today. It's not nearly as intimidating as I thought it would be.

<muurkha>maybe if you have qemu-user installed you can get test-all to work?

<roconnor>I got all the right answers for https://github.com/oriansj/stage0-posix/blob/master/x86.answers so that is nice.

<fossy>Mikaku: i've just been playing a bit with the kexec stuff you impl'd in Fiwix, and I tried to see if it could load GRUB (from which we could load anything) - this is the image I used http://ttm.sh/WG7.img. grub-file believes it is multibootv1 compliant. however it just hangs on the actual kexec invocation after shutdown. any ideas?

<muurkha>awesome!

<Mikaku>fossy: well I've only tested it with the Fiwix kernel and this ELF has different addresses in PLOADS

<Mikaku>fossy: anyway, did you changed the hard core entry address?

<Mikaku>unfortunately this is hard coded meanwhile I find a way to pass two values to 'ljmp' in inline assembly code

<Mikaku>(I'll be away for a couple of hours, sorry)

<fossy>Mikaku: no, i didn't missed that reading over the code! (no worries abt being away, TZ make this kind of thing very asynchronous anyways)

<Mikaku>fossy: I'll use the file WG7.img to fix the kexec code and make a little bit more generic

<fossy>thank you for your work!

<fossy>fwiw, if i change that hardcoded address to grub's entrypoint 0x00009000 it does boot grub - however grub fails due to some kind of memory corruption - not sure why yet

<Mikaku>fossy: I'm seeing that 'objdump -S' is unable to disassemble WG7.img, but I don't know why

<Mikaku>the command 'file' says the same for WG7.img and for Fiwix, the only difference is that symbols in WG7.img are stripped

<Mikaku>but that shouldn't suppose a problem

<Mikaku>fossy: is this WG7.img a kind of a kernel? I mean, what should I expect to see if it runs correctly?

<fossy>Mikaku: this is a multiboot GRUB image

<fossy>as in, GRUB compiled into multibootv1 compatible elf

<Mikaku>I see, and it loads and runs correctly when calling (like a kernel) from another GRUB?

<fossy>yep!

<fossy>hmmm, or maybe it doesn't, and grub is actually just resetting lol

<fossy>it's a bit difficult to tell the difference...

<Mikaku>ah! :-)

<Mikaku>well, I think GRUB expects to be executed in real-mode, which is not the case when using kexec

<fossy>really? when I kexec'd it, it produced "Welcome to GRUB" at least, and got stuck on a sanity check

<fossy>i thought that since the image (WG7.img) is multibootv1 compatible, it would work..

<Mikaku>I'm not sure, of course

<Mikaku>in any case, is strange that objdump is unable to disassemble it

<fossy>yes, i do find that rather strange

<stikonas[m]>roconnor: yes, you need qemu for non native arches

<stikonas[m]>fossy: but can you build grub with tcc?

<river>has anybody got a completely linear shell build script to build gcc? [please do not go to any trouble to answer this, this is not for anything useful. i am just wondering]

<fossy>stikonas[m]: do you need to? this is to kexec fiwix->linux - we can build it with gcc

<stikonas[m]>fossy: oh true, I forgot that this is for booting Linux

<stikonas[m]>And no, we don't have linear shell script for gcc

<oriansj>river: but it is possible to generate one from the output of running of the makefile

<stikonas[m]>But it will be machine or libc specific

<oriansj>indeed

<stikonas[m]>And will need to create some extra files that autotools does for us

<stikonas[m]>Such as config.h or something similar

<river>alright! sounds like no one has bothered to do this

<river>so its not really a useful thing to have lying around

<oriansj>well, makefiles really are much easier to maintain than the corresponding list of shell commands

<stikonas[m]>No, in live-bootstrap we stop writing completely linear scripts after tcc

<stikonas[m]>Then we build make and switch to makefiles

<stikonas[m]>Which are still a bit annoying to write without configure but a bit easier

<stikonas[m]>Then after perl we switch to autotools

<river>alright!

<stikonas[m]>Perl itself is already bad enough.to configure...

<stikonas[m]>See https://github.com/fosslinux/live-bootstrap/blob/master/sysa/perl-5.6.2/files/config.h

<oriansj>river: bootstrapping doesn't have to be useful; it just has to help you get to the place where you want to be. Useful to others is just a nice extra.

<stikonas[m]>And https://github.com/fosslinux/live-bootstrap/blob/master/sysa/perl-5.6.2/mk/main.mk

<Mikaku>fossy: I think finally managed to make WG7.img work, I see this <https://i.imgur.com/JFYPyGX.png>

<Mikaku>but the keyboard doesn't works, I'll try enabling interrupts ..

<Mikaku>fossy: do you know if GRUB configures the Interrupt Descriptor Table? that would be the cause that keyboard is not working

<Mikaku>anyway, the original problem was that the Fiwix kexec implementation didn't clear the "low" memory (from 0x0 to 0xA0000) before copying the new kernel

<Mikaku>so I guess that GRUB has uninitialized variables that it counts they will have a zero value

<Christoph[m]>I'd consider that an error of GRUB!

<Mikaku>Christoph[m]: yes, seems so

<Mikaku>but well, I guess GRUB assumes that it will be always executed right after a reboot

<stikonas>though in some modes it's definitely not true, e.g. UEFI gives no guarantees about state of memory

<stikonas>though maybe in that case grub does initialization but not in bios/multiboot mode

<stikonas>I remember when I was working on stage0-uefi, there were initially some bugs due to me not zero-initializing the memory (which we don't always do in stage0-posix)

<roconnor>building tcc from mes has scary warning. :)

<stikonas[m]>There are 3 warnings I think

<stikonas[m]>Though not very user frienfly

<stikonas[m]>Hard to tell what's wrong with tcc code

<stikonas[m]>Anyway, it's justba compile warning

IRC channel logs

2023-04-20.log