HybridCD and USB booting

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Pi_User5
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HybridCD and USB booting

Post by Pi_User5 »

I just built a hybridcd (revision 66074) and burned it to a Sandisk Cruzer 8GB.I booted off the USB drive by selecting the LiveCD RAM bootcd option in the boot menu on my Compaq nx6325 laptop. It actually boots and works! Normal USB liveCD stop loading at NDIS.sys! I will upload a video later.
I use ReactOS on real hardware. Will you? My Computers: https://www.reactos.org/wiki/PC_ROS_Rigs Go all the way to the bottom.

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fLuXx
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Re: HybridCD and USB booting

Post by fLuXx »

It would be a good idea to write a detailed tutorial at the subforum for that. Many people would like to try using it with a USB drive.

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EmuandCo
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Re: HybridCD and USB booting

Post by EmuandCo »

Do you see the SanDisk in ROS then? I guess you only see the RamDisk, right?
ReactOS is still in alpha stage, meaning it is not feature-complete and is recommended only for evaluation and testing purposes.

Pi_User5
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Re: HybridCD and USB booting

Post by Pi_User5 »

It would be a good idea to write a detailed tutorial at the subforum for that. Many people would like to try using it with a USB drive.
I will do that.
Do you see the SanDisk in ROS then? I guess you only see the RamDisk, right?
I only saw the RAMDisk. USB does not work on my laptop even when I installed ReactOS to the hard drive.
I use ReactOS on real hardware. Will you? My Computers: https://www.reactos.org/wiki/PC_ROS_Rigs Go all the way to the bottom.

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Aeneas
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Re: HybridCD and USB booting

Post by Aeneas »

Sometimes there is some form of "hardwired emulation". For instance, often USB-floppy-drives are being shown to the OS as being "hardwired", if the OS boots from them - that, at least, is how one of my machines handles DOS floppies over USB just fine.

But then the feature is machine-dependent - not something ReactOS can rely on.

Pi_User5
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Re: HybridCD and USB booting

Post by Pi_User5 »

Sometimes there is some form of "hardwired emulation". For instance, often USB-floppy-drives are being shown to the OS as being "hardwired", if the OS boots from them - that, at least, is how one of my machines handles DOS floppies over USB just fine.

But then the feature is machine-dependent - not something ReactOS can rely on.

A nice explanation by hbelusca about why it works:
Yep, same here. When being loaded in RAM, things work because ReactOS recognizes that there is the ramdisk which is the boot device. But when booting directly from e.g. USB key or some of external CD drives (as in my case), the bootloader works (because it uses BIOS functions to talk with the hardware, and the BIOS knows how to deal with the external CD/USB), but when it comes to ReactOS that uses drivers to (try to) talk directly with the hardware (without using the BIOS), things start to not work properly, and as a result the external CD drive (or USB key) is not detected anymore, and no boot device is found, and then BSOD "IO1_INITIALIZATION_FAILED" or some other "INACCESSIBLE_BOOT_DEVICE" ....
I use ReactOS on real hardware. Will you? My Computers: https://www.reactos.org/wiki/PC_ROS_Rigs Go all the way to the bottom.

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alexei
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Re: HybridCD and USB booting

Post by alexei »

Booting from USB HDD (if you interested):
1. Depending on motherboard, drive geometry returned by BIOS may differ, so you cannot rely on this information.
2. That means you have to hardcode location of the active partition in the MBR code or determine it from the partition table.
3. If you want it to boot on very old motherboards, on which BIOS does not support INT 13 reads by LBA, you have to translate CHS of actual drive geometry to CHS in geometry considered by BIOS. Othervise just read by LBA.
BTW, because drive geometry considered by BIOS and the one, with which the drive was formatted may differ, attempts to boot older versions (up to XP/2003) of MS Windows from USB often fail. Same happens whith IDE/SATA HDD if they were not partitioned by Windows installation. That's why booting Windows moved to HDD formatted from Windows usually fail.
The above is based on some research I made 8+ years ago.
I could mess up with some details, it was rather long time ago :)
How does ROS handle these geometry issues?

Pi_User5
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Re: HybridCD and USB booting

Post by Pi_User5 »

Do you see the SanDisk in ROS then? I guess you only see the RamDisk, right?
I just retested and I was able to access the USB drive.
I use ReactOS on real hardware. Will you? My Computers: https://www.reactos.org/wiki/PC_ROS_Rigs Go all the way to the bottom.

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mhmohammadi
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Re: HybridCD and USB booting

Post by mhmohammadi »

Would you mind uploading the ISO file (HybridCD) that used for making usb flash ? or at least giving a link to where you downloaded ?
thank you

Pi_User5
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Re: HybridCD and USB booting

Post by Pi_User5 »

Would you mind uploading the ISO file (HybridCD) that used for making usb flash ? or at least giving a link to where you downloaded ?
thank you
You have to build it. However, you can download one from here but it's from January. http://sourceforge.net/projects/reactos ... z/download
I use ReactOS on real hardware. Will you? My Computers: https://www.reactos.org/wiki/PC_ROS_Rigs Go all the way to the bottom.

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