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 Post subject: "Guest has not initialized the display (yet)" [Solved]
PostPosted: Thu Feb 28, 2019 5:34 pm 
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Joined: Thu Feb 28, 2019 6:50 am
Posts: 11
Hi, I've tried custom bioses on qemu and pressing esc after the splash screen, but nothing does it.
Any help appreciated !


Last edited by Teln0 on Fri Mar 01, 2019 6:37 am, edited 2 times in total.

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 Post subject: Re: "Guest has not been initialized"
PostPosted: Fri Mar 01, 2019 2:49 am 
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Do you mean "guest has not initialized the display"? If so, it sounds like the custom BIOS you're using doesn't support whatever graphics hardware QEMU is emulating.

Why are you using a custom BIOS?


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 Post subject: Re: "Guest has not been initialized"
PostPosted: Fri Mar 01, 2019 3:09 am 
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I get that occasionally with no apparent pattern... Since it's obviously happening long before any of my code starts running, I just assume it's a bug in QEMU and just try again.

My entirely unfounded suspicion is that there's a race between the code that initializes QEMU's graphics output and the code that initializes the emulated graphics card and if the output initialization takes too long (I usually see the issue when using QEMU's VNC output), the emulated graphics card either doesn't initialize or initializes "headless" and produces no output.

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 Post subject: Re: "Guest has not initialized the display (yet)"
PostPosted: Fri Mar 01, 2019 4:29 am 
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Joined: Thu Feb 28, 2019 6:50 am
Posts: 11
Here is some more details :

The splash screen appears after
mov ax, 0x004F
int 10h
which is supposed to give me VESA info.
Here are the registers according to GDB :
eax 0x3d 61
ecx 0x6db0 28080
edx 0x402 1026
ebx 0xf5318 1004312
esp 0x6d90 0x6d90
ebp 0x6db0 0x6db0
esi 0x80000 524288
edi 0xf3e27 998951
eip 0xee49b 0xee49b
eflags 0x6 [ PF ]
cs 0x8 8
ss 0x10 16
ds 0x10 16
es 0x10 16
fs 0x10 16
gs 0x10 16


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 Post subject: Re: "Guest has not initialized the display (yet)"
PostPosted: Fri Mar 01, 2019 5:17 am 
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Teln0 wrote:
The splash screen appears after
mov ax, 0x004F
int 10h
which is supposed to give me VESA info.

No, if you want VESA info you have to put 0x4F00 into AX.


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 Post subject: Re: "Guest has not initialized the display (yet)"
PostPosted: Fri Mar 01, 2019 6:37 am 
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Joined: Thu Feb 28, 2019 6:50 am
Posts: 11
Yes, I have tried both (just in case). The real problems were
1 - GDB, somehow
2 - I forgot [bits 16] because it was following a [bits 32] section


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