China DOS Union

I used the grub_for_dos-0.4.0pre4.tar.gz package, copied it to the hard disk of the virtual machine and executed
ROOT (FD0)
SETUP (FD0)
Install GRUB to the floppy disk. Then I deleted all the files on the floppy disk and only kept GRLDR. I made an IMA image and successfully booted in the virtual machine. I also made an ISO and successfully booted in the virtual machine. However, the problem mentioned by blue is really strange. I can boot from the floppy disk using the IMG file he provided, but I can't boot from the CD-ROM when making it into an ISO.
All the above experiments were carried out under VPC2004 (VIRTUAL PC 2004).

There is one thing that I find strange. I deleted grldr (at this time it looks like a blank disk), and I can still boot to the GRUB menu interface completely relying on the boot information of the floppy disk. But I also encountered the situation described by blue. In other words, it is not successful every time to boot. Here, it is more serious. Sometimes even the made floppy disk IMA image cannot be booted (at this time, the floppy disk cannot be booted, and only the 4 characters "GRUB" flash). Currently, further testing is in progress. Tried again and succeeded. The steps are as follows:
Establish the BOOT\GRUB directory in A:, and copy STAGE1 and STAGE2 to this directory.
Run GRUB.EXE from C:, and execute the command to install to the floppy disk.
Then delete the BOOT directory, and the IMA boot is successful, and the ISO boot is successful.
Hope more friends can test.
Finally, I would like to ask Budian and blue, can I directly run GRUB from the CD instead of making it into a boot floppy IMG and then integrating it into the CD? If there is, can you inform the method and related downloads? Thank you! I know that it can be achieved by using BootLoader for Grub or EASYBOOT.

> I tested it under the virtual machine VPC version 5.2. The CD-making tool is UltraISO. The three possibilities you mentioned do not exist. Well, I will upload the grldr.img I made. This image uses the latest grldr from your FTP on March 9. It can start normally when used on a floppy drive (real, virtual, virtual machine), but cannot start when made into a bootable CD. Please test it to see what the reason is?

I just made a CD with the grldr.img you provided. It is displayed normally in the menu when started with qemu, and also normally when started with a real machine. This basically can confirm that the virtual machine you are using is too bad. Otherwise, you can also test with a real machine to see if it is normal? Or you can change to another virtual machine to test, see how it is?

> I used the grub_for_dos-0.4.0pre4.tar.gz package, copied it to the virtual machine's hard drive and executed
> ROOT (FD0)
> SETUP (FD0)
> Install GRUB to the floppy disk, then I deleted all the files on the floppy disk and only kept GRLDR, .......
> You don't need to read further. This approach is wrong. Your installation uses the old-fashioned GNU GRUB method (root, setup, etc.), but you want to boot GRLDR, which is impossible. You must follow the GRLDR installation method (find relevant instructions yourself, such as http://grub.linuxeden.com/), only then can you boot GRLDR, otherwise, you can only boot the old-fashioned stage2 file.

> Tried it again, and it succeeded. The steps are as follows:
> Create the BOOT\GRUB directory in A:, and copy STAGE1 and STAGE2 to this directory
> Run GRUB.EXE from C:, and execute the command to install to the floppy disk
> Then delete the BOOT directory, the IMA boot is successful, and the ISO boot is successful.

You deleted the directory containing stage2, and it can still boot to GRUB. This is the funny thing about the original old-fashioned GNU GRUB installation method, which is unsafe. Once you copy a file to overwrite the physical space occupied by the stage2 file, your boot will immediately fail. Therefore, although you deleted the boot directory, you cannot use these spaces to store other files.

> Finally, I want to ask BuDian and blue, can I run GRUB directly from the CD, instead of making it into a bootable floppy disk IMG and then integrating it into the CD? If there is any, can you inform the method and related downloads, thank you! I know that this can be achieved by using BootLoader for Grub or EASYBOOT.

"Run GRUB directly" seems ambiguous. How is it considered direct? If you mean the no-emulation mode CD boot standard, then searching for stage2_eltorito in a search engine will let you know the method to install GRUB directly to the CD. I just uploaded the pre4 stage2_eltorito file to the FTP space:

ftp://ftp.linuxeden.com/tinybit/stage2_eltorito

After reading the relevant articles you searched, you can use this file to make your GRUB bootable CD.

For the GRUB bootable CD, please download it from the following link: http://bbs.wuyou.com/cgi-bin/topic.cgi?forum=34&topic=7376. Then, use this file as the CD boot file. You can load it with ULTRAISO or call it with EZB. Just make sure to place a STAGE2 file in the BOOT folder of the CD. Otherwise, the boot file won't find STAGE2 and GRUB won't be able to start. Also, all the paths after (cd)/ in your MENU.LST need to be in uppercase. OK?

The current pre4 version is quite cumbersome. When booting, if you don't press a key manually, you have to wait 5 seconds for the boot MBR and then another 5 seconds to find grldr. The 0.4.0pre and previous versions don't need that. To be honest, the MBR function is a chicken rib for my computer because I have a single hard disk and a single partition. I've looked at the code of grldr, hehe, I'm very amateurish and can't understand it, but why is the code that can set the default path of menu.lst written before boot previous MBR, and no matter how I set it, it doesn't get executed? What other methods are there or how to modify it so that I don't have to wait those two 5 seconds? Which part of the code can be modified to change the timeout of these two commands from 5 to 0?

GRUB4DOS is still too large compared to floppy disks. Let's switch to SYSLINUX, combined with MEMDISK. No need for any DOS EXE/SYS compression tools, because MEMDISK supports ZIP and GZ formats. The boot floppy disk I made myself is very concise, with only six files in the root directory: LDLINUX.SYS, MEMDISK, SYSLINUX.CFG, DOS.ZIP, SBM.GZ, CIA.GZ. Among them, three are images. Of course, SYSLINUX has fewer functions, but it's just right for floppy disks. As for GRUB4DOS, I think it's better to use it on hard disks, CDs, or USB drives.

Esme：

pre4 is for testing. In the official version, the previous MBR will no longer be executed by default. Now if you change the third byte 00 at the beginning of GRLDR to hexadecimal 80, then this function is disabled, and the official version will do so. There is no way to modify the timeout value. If you want to modify it, you can only directly modify the source code.

In the future, the versions released by me will no longer look for menu under boot/grub/, but only look for the menu.lst file in the root directory. So the menus in the boot/grub/ directory before will all become invalid. The reason for changing it now is because I found that there are big problems with the NTFS module. Sometimes it cannot correctly open files in subdirectories, but can open files in the root directory normally. By the way, if everyone wants to simulate and run a certain img file, please note that put the file in the root directory of NTFS, otherwise, it may fail to open it, or although it can be opened, the file content obtained is wrong.

dear tinybit,wish you release the new version of grldr as soon as possible!

Thanks! After I changed 00 to 80, the previous MBR is indeed no longer executed, but I found a new problem. It seems there is a conflict between pre4 and ntfsdos pro. After I use the virtual floppy disk img to boot normally and execute ntfsdos pro, it shows that the ntfs disk is successfully found and the drive letter is set to c. But then no matter what command I execute next (under the virtual drive a), even commands like dir, cd.., the computer will crash. The pre version has no such problem and everything is normal.

ntfs4dos is much better than ntfs pro

Don't worry everyone, there are no major issues with pre4. I originally intended to release it as the official version. But it seems there are still some small areas that need to be supplemented or improved. The first is that the previously mentioned previous MBR will no longer be executed preferentially (but will be executed only after failing to find GRLDR); the second is that the stage2_eltorito file was omitted in previous versions, which is used to make bootable CDs in no-emulation mode, and it will be included in the next release.

> But I found a new problem, it seems there is a conflict between pre4 and ntfsdos pro in interrupts.
> After I normally boot with the virtual floppy img and execute ntfsdospro, it shows that the ntfs disk is successfully found, and the drive letter is set to c. But then no matter what command I execute next (under the virtual A drive), even commands like dir, cd.., the computer will crash. The pre version has no such problem and everything is normal.

I'm not very clear about this. Pre4 has made a lot of improvements in the disk emulation code compared to pre, removing many errors. Currently, I think the emulation code part is very robust and there shouldn't be any problems, big or small. Note that our --mem all use int15 to handle various memory operations, such as determining the size of extended memory, moving memory blocks between conventional memory and extended memory, etc. If a software has a BUG, of course it may fail under the new version. When I wrote this emulation program, I have read all the industry specifications, and these specifications I collected can be found on http://grub.linuxeden.com/.

But since the problem has occurred, we should still try our best to find the reason, if possible. Before pre4, pre2 and pre3 were also released. Please further check if they have any problems and report the test results, so that I can judge the root cause of the problem. Thank you in advance.

Hehe, I don't know where to download pre2 and pre3, or even pre, because after downloading pre4, I deleted the previous ones. The new DOS only has the latest one, and the FTP on the forum can't be opened.

This FTP can be opened. If it can't be opened, try again after half an hour:
ftp://ftp.linuxeden.com/tinybit/