#1459 CDROM and LBA
I am using Bochs 2.7 and have created a CDROM with a hard disk image as per El Torito. The issues are:
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I cannot use the LBA functions to read from this hard disk image, even though Virtualbox can and even though real hardware can.
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Bochs sets the geometry, which is fine, but for a 490 MB image, it makes the heads 14 and sectors 14 (same as Virtualbox - both seem odd to me). But this means only about 100 MB of the image is actually accessible (at least it should be) via CHS addressing with a maximum of 1024 cylinders. So that's not appropriate geometry if LBA was deliberately denied for a reason.
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In actual fact, Bochs only allows 256 cylinders. If I attempt to set bits 6 and/or 7, the read fails - by which I mean that it doesn't read anything at all - it doesn't just ignore those bits and give me a sector within reach.
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I tried to create a smaller, 40 MB image, so that it would all be within range. Instead, Bochs changed the geometry to 2 heads and 9 sectors so almost nothing was in range.
What I eventually did to get a bootable hard disk image was to create a 490 MB disk image with a small amount of data on it (less than 20 MB), so that everything was within range of the strange geometry and strange restrictions. There may well be a technically valid reason for these restrictions so it may not be a bug. I have a working and failing (on Bochs, not Virtualbox) ISO image available at http://pdos.org if you want samples.
The latest PDOS ISO image boots now with Bochs, so I'll close this bug report now. Please create an issue on Github if there are still problems with PDOS on Bochs.