How the reactos start?

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leiting
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How the reactos start?

Post by leiting »

Which program is led at the first? Which is next? What is the order that the os start?What is the sequence that progarms play?
My English is bad.I don't know can you understand me.But please give me an answer if you see it.Thank you!

ThePhysicist
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Post by ThePhysicist »

Windows NT (and ROS) startup sequence is described here:
http://en.wikipedia.org/wiki/Windows_NT_Startup_Process
Hope this helps.

leiting
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Joined: Sun Jun 11, 2006 4:01 am

Post by leiting »

ThePhysicist wrote:Windows NT (and ROS) startup sequence is described here:
http://en.wikipedia.org/wiki/Windows_NT_Startup_Process
Hope this helps.
The link"http://en.wikipedia.org/wiki/Windows_NT ... cess"can't scan in my computer!

Megari
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Joined: Sun Jan 09, 2005 12:19 am

Post by Megari »

leiting wrote:
ThePhysicist wrote:Windows NT (and ROS) startup sequence is described here:
http://en.wikipedia.org/wiki/Windows_NT_Startup_Process
Hope this helps.
The link"http://en.wikipedia.org/wiki/Windows_NT ... cess"can't scan in my computer!
It is there for sure - I am reading it at the moment. You don't happen to have Wikipedia blocked somehow, do you? I don't know where you're from, but if you happened to be from China (which may not be the case according to your username, though), the site would be blocked by the government. Please try opening the page again.
Wag the dog.

GreatLord
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Post by GreatLord »

ReactOS and Windows NT startup process is bit diffent

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Jaix
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How different?

Post by Jaix »

GreatLord wrote:ReactOS and Windows NT startup process is bit diffent
GreatLord, can you develop that statement a bit please, what is different and how different is it?
Last edited by Jaix on Fri Jun 23, 2006 5:06 pm, edited 1 time in total.

ThePhysicist
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Post by ThePhysicist »

leiting wrote:The link"http://en.wikipedia.org/wiki/Windows_NT ... cess"can't scan in my computer!
Try this link. It's the same page accessed through anonymouse.com.
If it's also blocked, this site has a list of anonymous web proxys, try if one of those works for you,

@GreatLord: I'm interested in the differences, too.

GreatLord
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Post by GreatLord »

I do not the whole process
1. ReactOS does not have NTLDR

I will try desc the process as I understand it

ReactOS boot sector is 2kb big and windows nt boot sector is 512bytes big. Normal a pc can not read more that 512 byte boot sector, but we chain loading some sectors and run that code. The boot code is loading freeldr.sys into memory and freeldr.sys put the cpu into protected mode.

freeldr.sys
is starting loading minum set of drv for hardware. only most nesnary.
then u see the boot menu in freeldr. so it loading ntoskrnl.exe and other stuff. like graphic drv, filesystem drv, keyboard drv, and so on.

ReactOS boot process is diffent against Windows NT

freeldr is not ntrdrl compatible

Wierd
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Post by Wierd »

If my memory serves me correctly, this is how it works on NT, 2k, and XP:

The bios looks on the bootsector for the active partition, then starts its boot sector. This is, by tradition, 512 bytes long. This sector points to a filed called NTLDR, which starts the NT HAL, and NTOSKRNL. NTLDR contains a very limited filesystem driver to accomplish this feat, if memory serves.

Once control is passed to the HAL, it loads several drivers into kernel space, and passes control to NTOSKRNL. NTOSKRNL then loads other boot-time drivers, and sets up housekeeping.

This is different from what Freeldr does with ReactOS. Freeldr is chainloaded from the bootsector in a less elegant manner, as Greatlord mentioned. It also does some of the things the HAL does for NT on startup, such as loading some filesystem drivers, generic miniport drivers for VGA, etc... It kinda gives our HAL a helping hand, by preloading some things into memory. It then passes control to our HAL, which loads other drivers, and starts NTOSKRNL, which sets up housekeeping.

I have never really looked inside Freeldr, but I do know that our current environment staunchly needs functionality it provides. Basic services that Freeldr provides have to be hacked into other platform modules, for ported machine archs-- such as PPC. IIRC, Arty(?) was working on the PPC port, and has been having the PPC "Freeldr" have OpenFirmware do a lot of its dirtywork, with pretty good results. Simmilar things will probably have to be done for other archs as well. I think some work was done to make Freeldr more NTLDR like, but I dont know how far that went, of if anything useful materialized at all--- I just saw some talk about such things about 5 months ago or more on the mailing lists. IIRC, Alex was the one suggesting that such a thing be done.

Everything I say should be taken with a grain of salt, because it is nearly 11:00 PM, and I am tired, sunburnt, with cramping legs-- on top of my memory sometimes generating some rather obscure outputs. It's a shame human brains dont come with filesystem checkers............ LOL.

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Jaix
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Interesting.

Post by Jaix »

Well, this was interesting and informative, thanks GreatLord and Wierd.

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