中国DOS联盟

successful test in qemu, see post #7


(1)
used to extract boot sector and plopbt.bin from the plopcdflp12.iso into C/H/S 7/1/16 63KB floppy image came from ROMOS. then use rcompile.bat to generate the romos.bin containing the plop boot manager(boot sector + lopbt.bin).

results:
qemu boots to ROMOS but hangs the VM, displaying:
plop bt bin

(2)
trial of boot from qemu and use the 63KB plop.img as floppy a:

result:
ok, successful enterd plop manager.

(2)
trial of putting plop.img into a grub4dos.img,

code:
map --mem (fd0)/plop.img (fd1)
map (fd0) (fd1)
map (fd1) (fd0)
map --hook
chainloader (fd0)+1
disk error

root (fd0)
boot

same as case(1)

conclusion: not ready to put the plop into BIOS

[ Last edited by uleak on 2008-7-11 at 11:32 AM ]

用法错误。map --mem (fd0)/plop.img (fd1) 之后又来一个 map (fd0) (fd1)，那么其结果就是，后者覆盖了前者，因此前者不起作用，只有后者起了作用。

应该这样：

map --mem (fd0)/plop.img (fd0) map --hook chainloader (fd0)+1 rootnoverify (fd0) boot

sure, after enter the grub menu, the fd0 containing grldr is not needed any more, since the grub is used to deal with emulation for fd1 and bootstrap to plop manager's boot sector.

for general speaking, the problem is for unknown reason, the ROMOS FDD emulation code cant work well with plop boot sector but qemu emulation does. the grub FDD emulation is not working for uncommon 63k image, as grub is well known excellence support for typical 1.44M image in this case.

since qemu can employ my 63k fdd.img and bootstrap into plop main program, then i can assume the fdd image is in good shape.

here the conclusion had made, ROMOS is stall for years, and i am incapable for modify the source. And grub4dos is too large for 64k bin, with a 63k img embedded. so pci rom is not ready.

grub4dos 有多个发展方向。比如：grub2 是一个方向。改造 Linux 使其成为引导器是一个方向。精简grub4dos，用汇编代码来节约空间，则是又一个可能性。

另外，我感觉你的 63K img 应该是能够用 map 启动的，我猜测你的 img 不是一个 FAT 文件系统，因此，map 未能探测出一个合适的 CHS 值。你需要在 map 命令行中指定 --heads= 和 --sectors-per-track= 来搞定。cylinders 的值是无需指定的。

>我感觉你的 63K img 应该是能够用 map 启动的
true, this is a mappable img, my mistake.

my tailor-made 63k plop manager image 7-zipped
http://upload.cn-dos.net/img/588.7z

this is from the ROMOS 63K USB boot disk image

i use ultraiso to inject plopbt.bin into the image, the boot sector same as well.

mapped by grub4dos, boot-loaded as fd0, error as stalls. not clear which of this is a boot sector error, or plopmanager refuse run under grub4dos with this uncommon disk image, since the zipped plop.img with 1.44M typical size image is working.

the geometry cmd report of 1.44M zipped floppy image is CHS 80/2/18, 2880/512
and the 63k image is LBA 7/1/18, sector count is 126/512

don't know if this difference is due to ultraiso save the 1.44M boot sector into 63k image or not.

latest screen output when 63k image is used:
.....................

刚刚试验过了，用下面的代码可以启动成功：

map --mem --heads=2 (fd0)/plop.img (fd0) map --hook chainloader (fd0)+1 rootnoverify (fd0) boot

这证明你的 63K FAT 映像，实际上是 H=2，S=18 的。而你在这个 FAT 的 BPB 表中却错误地设置了 H=1，这就是错误的根源。

Hi there,
the plop manager is now embedded by the ROMOS pci rom within 64k, bootable, successful boot into plopmanager. this is a PCI rom image, so it can be inserted into bios.

download here:
http://upload.cn-dos.net/img/589.7z

Thanks tinybit.

Regards,
uleak