China DOS Union

The following is quoted from 不点 on 2004-2-13 1:26:32:
The installer is a built-in function of GNU GRUB. It only uses those stage files under the boot/grub/ directory. There is no way for us to change that.

Since our GRUB for DOS/NTLDR requires the system to be able to boot into a certain state , our GRUB for DOS/NTLDR cannot be installed directly into the MBR. But you can also try this as an experiment:

Put the program code of BOOTGRUB into the MBR, but keep the partition table at the end of the MBR , and do not damage the partition table . In this way, our GRUB for NTLDR can be started from the MBR instead of from the NTLDR menu. Since we still use GRLDR, doing it this way is not affected by disk defragmentation.

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Background images are now supported; please download and test:
ftp://211.100.7.71/incoming/grub_for_dos-0.2.0pre2.tar.gz

This time support for splash image backgrounds has been added. After extracting, you can find the program files with splashimage functionality in the splash directory.

This test is mainly to see whether the splashimage background works properly. Note: you should use the files in the splash directory for testing.

How do you write BOOTGRUB into the MBR? Will that affect NTLDR? If it does, and the system is installed on an NTFS partition, then how would Grub be used to boot the system on the NTFS partition?

At present there is still no command provided for writing BOOTGRUB into the MBR. We may do this later if we get the chance.

Write the first 446 bytes of BOOTGRUB into the MBR boot sector, but keep the partition table in the MBR unchanged. The partition table is located in the last 66 bytes of the MBR sector. 446 + 66 = 512, so you absolutely must calculate it accurately!!!! If the partition table is accidentally destroyed, all the data on the hard disk could be gone!!!!

As for what tool to use to write it, that doesn't matter. You can use debug, or you can use LINUX's dd command. In this matter, "let each display his special abilities," so I won't say more. Anyone unfamiliar with debug, or who doesn't know how to use the dd command, should not try doing this.

Installing it this way will not affect NTLDR.

Enter the following at the GRUB command line:

chainloader (hd0,0)+1
rootnoverify (hd0)
boot

and NT will boot.

Here it is assumed that (hd0,0) is your NTFS partition, and it is drive C:.

pre3 has been uploaded:
ftp://211.100.7.71/incoming/grub_for_dos-0.2.0pre3.tar.gz

Please test this version thoroughly.

See whether GRLDR under FAT16 can run normally.

See whether the splashimage-version files in the spalsh directory can display background images.

I just tried this new version, and found that using the splashimage command to display that test XPM succeeded, nice! Also, GRLDR started successfully on both FAT16 hard disks (but according to the test results under the Bochs virtual machine, GRLDR still fails to start under FAT12).

The following is quoted from 不点 on 2004-2-14 10:49:30:
At present there is still no command provided for writing BOOTGRUB into the MBR. We may do this later if we get the chance.

Write the first 446 bytes of BOOTGRUB into the MBR boot sector, but keep the partition table in the MBR unchanged. The partition table is located in the last 66 bytes of the MBR sector. 446 + 66 = 512 , so you absolutely must calculate it accurately!!!! If the partition table is accidentally destroyed, all the data on the hard disk could be gone!!!!

As for what tool to use to write it, that doesn't matter. You can use debug, or you can use LINUX's dd command. In this matter, "let each display his special abilities," so I won't say more. Anyone unfamiliar with debug, or who doesn't know how to use the dd command, should not try doing this.

Installing it this way will not affect NTLDR.

Enter the following at the GRUB command line:

chainloader (hd0,0)+1
rootnoverify (hd0)
boot

and NT will boot.

Here it is assumed that (hd0,0) is your NTFS partition, and it is C: drive.

Dear TinyBit,

Could you upload those 446 bytes of BootGrub here, so that I can download and have a trial?

Thank you.

These 446 bytes are simply the first 446 bytes of bootgrub.
Take the first 446 bytes of BOOTGRUB plus the last 66 bytes of the MBR
to form one 512-byte sector, and write this new sector into the MBR. That will do.

The following is quoted from Wengier on 2004-2-14 14:14:40:
剛才用這個新版本試了一下，發現用splashimage命令顯示那個測試XPM成功，不錯！而且GRLDR在FAT16的兩個硬盤下均啟動成功（不過據在Bochs虛擬機下的測試結果，GRLDR在FAT12下仍啟動失敗）。

Thanks. Then the only problem left is FAT12. Please test on a real machine if possible. If it fails, please provide the MBR and the first 16 sectors of the partition.
Also, please describe the failure symptoms in detail. Also, when it fails, please try whether grub_for_ntldr-test003/004 succeeds.

Question for big brother 不点: I already have a Boot\Grub directory on C. Should I put splash under boot, or under Grub, or use only one of those image display files? Thanks...!

It doesn't matter where the xpm.gz file is placed.

grub> splashimage (hd0,0)/..../..../..../myphoto.xpm.gz

That is, you only need to specify the path on the command line.

Delete the old boot/grub directory on your C: drive, and replace it with the boot/grub from inside the splash directory.

Put all the files from the splash directory into the root directory of drive C:. There should not be a splash subdirectory under C:.

The following is quoted from 不点 on 2004-2-14 19:13:03:

The following is quoted from Wengier on 2004-2-14 14:14:40:
剛才用這個新版本試了一下，發現用splashimage命令顯示那個測試XPM成功，不錯！而且GRLDR在FAT16的兩個硬盤下均啟動成功（不過據在Bochs虛擬機下的測試結果，GRLDR在FAT12下仍啟動失敗）。

Thanks. Then the only problem left is FAT12. Please test on a real machine if possible. If it fails, please provide the MBR and the first 16 sectors of the partition.
Also, please describe the failure symptoms in detail. Also, when it fails, please try whether grub_for_ntldr-test003/004 succeeds.

Dear TinyBit,

We have just tested using your Pre3 by putting BootGrub's first 446bytes into MBR with GRLDR in the root directory of either an active FAT16 or FAT32 primary partition.

But it fails and displays the following error message:

Error: NT Boot Partition not found, press Ctrl+Alt+Del to restart.

Could you explain the exact booting mechanism and if NT Boot Partition is required?

to brother windrv:

Yes, at present an NT partition must exist. If there is no NT boot partition in the system, then BOOTGRUB cannot run.

Note that what this means is that there must be an NT boot sector present; it does not require that NTLDR itself must exist. Our BOOTGRUB uses NT's boot record to boot the GRLDR file. If you only have a DOS/win9x boot record, then it cannot boot the GRLDR file.

It searches for an NT boot record among the four partition table entries in the MBR. If none of the four primary partitions has an NT boot record, then it displays the error message you saw.

Later I will write another piece of code to support those partitions without NT boot code. Please wait patiently.

The following is quoted from 不点 on 2004-2-15 11:17:15:
to brother windrv:

Yes, at present an NT partition must exist. If there is no NT boot partition in the system, then BOOTGRUB cannot run.

Note that what this means is that there must be an NT boot sector present; it does not require that NTLDR itself must exist. Our BOOTGRUB uses NT's boot record to boot the GRLDR file. If you only have DOS/win9x boot record, then it cannot boot the GRLDR file.

It searches for an NT boot record among the four partition table entries in the MBR. If none of the four primary partitions has an NT boot record, then it displays the error message you saw.

Later I will write another piece of code to support those partitions without NT boot code. Please wait patiently.

Dear TinyBit,

Is it possible just to use Syslinux to boot up GRLDR?

Have you tried that out?

I haven't tried it.

Based on my previous impression of syslinux, I feel that syslinux is quite limited in functionality. It can work on a FAT partition, but it seems it cannot work very well on other types of partitions. I have no plans to use syslinux. I feel that syslinux's technology may be somewhat outdated.

The following is quoted from 不点 on 2004-2-16 14:44:59:
I haven't tried it.

Based on my previous impression of syslinux, I feel that syslinux is quite limited in functionality. It can work on a FAT partition, but it seems it cannot work very well on other types of partitions. I have no plans to use syslinux. I feel that syslinux's technology, may be somewhat outdated.

Hi TinyBit,

What is the difference between your GRUB.EXE and GRLDR?

Could we rename GRLDR into GRLDR.EXE and run it?

The difference is in the header.

GRLDR has only a one-sector header, while GRUB.EXE has an 8-sector header. The rest of the parts are the same; they are the pre_stage2 file.

GRLDR is not a normal EXE file, nor can it be regarded as a .com file. It cannot be run simply by renaming it to .exe.