dedicated" mode. This was specifying that there are 256 (illegal!)
heads on the disk. If bioses store that in a byte, and it gets truncated
to 0, then that almost certainly causes the infamous divide-by-zero
nightmare.
This is also most likely the reason why the Thinkpad T20/A20 series
were locking up when FreeBSD was installed. This is also the most likely
reason why a boot1 being present causes an IA64 box to lock up at boot.
(removing the "part4" stuff from boot1.s fixes the IA64 boxes and would
most likely have fixed the T20/A20 and some TP600E series thinkpads)
Remove asm functions to call the openfirmware and kernel entry points;
we can just call them directly.
Don't use the stack pointer for an intermediate result in setx.
Put the stack in the bss.
Firmware.
- Add a temporary disklabel header to boot off a NetBSD/sparc64
partition. This file can be deleted when we have got a FCode
bootblock.
The disklabel header was obtained from NetBSD.
- Use unsigned types for the (32-bit) Open Firmware device handles
to avoid sign extension on 64-bit architectures.
- Add a standard type definition for Open Firmware arguments.
- Flesh out ofw_readin routine.
- Add OpenFirmware load and exec routines.
- Make sure memory allocation for the kernel is done correctly.
- Change the way the heap is allocated so as to make it easier to deallocate
when we hand over.
- Add a command to print memory maps similar to the one for ia64.
With this patch, I can now load and hand over to a kernel on my iMac. There
are some problems with OpenFirmware routines failing after the hand over that
still need to be addressed.
- When the video BIOS is called to clear the region (x, y)-(79, 24)
(by scrolling), the slashed region in Fig.1 is cleared. CD() is
supposed to clear the region shown in Fig.2.
x x
+-------+ +-------+
| | | |
y| ////| y| ////|
| ////| |///////|
| ////| |///////|
+-------+ +-------+
Fig.1 Fig.2
- Don't move the cursor during this operation.
- Be consistent about placing spaces around keywords and
operators; don't mix statements like "if(A==B)" and "if (X == Y)",
"return(0)" and "return (-1)", "P=10" and "Q = 0", etc.
- Consitently indent lines. It's not good to indent by 8 columns
in one part of the file, and by 4 columns in the other part.
