From 0be74eeee017b7116126e258b97df5a857dac4ab Mon Sep 17 00:00:00 2001 From: Andreas Baumann Date: Fri, 9 Jun 2017 21:40:05 +0200 Subject: tried to probe disk geometry with mixed success (emulated FDD mode on USB not working). Code in stage1 gets too complex to fit 512 bytes, so we most likely must load stage2 with a simple algorithm (maybe 8 sectors every bios 13h/2h function is able to deliver). Then we load the kernel in a second, more complex loading step --- doc/LINKS.TODO | 1 + doc/README.DISK_GEOMETRY | 66 +++++------------------------------------------- 2 files changed, 7 insertions(+), 60 deletions(-) (limited to 'doc') diff --git a/doc/LINKS.TODO b/doc/LINKS.TODO index 81e0466..c51106b 100644 --- a/doc/LINKS.TODO +++ b/doc/LINKS.TODO @@ -70,6 +70,7 @@ https://www.cs.cmu.edu/~410-s07/p4/p4-boot.pdf http://www.osdever.net/tutorials/view/loading-sectors http://www.osdever.net/tutorials/view/lba-to-chs LILO boot loader +http://www.uruk.org/orig-grub/PC_partitioning.txt C: http://www.drdobbs.com/extending-c-for-object-oriented-programm/184402731 diff --git a/doc/README.DISK_GEOMETRY b/doc/README.DISK_GEOMETRY index 54f6092..5001679 100644 --- a/doc/README.DISK_GEOMETRY +++ b/doc/README.DISK_GEOMETRY @@ -2,69 +2,15 @@ This affects the boot loader in stage 1 using BIOS functions to read stage 2 and the kernel Geometry Specification - -360 KB 5.25" - +(emulated) floppy gives us -1.2 MB 5.25" - +0x0101, 0x4f12 -720 KB 3.5" - +which is 2 heads, 80 sectors, 18 sectors, sounds good -1.44 MB 3.5" - +Asus, Eeepc 701, pendrive 16 gb: -2.88 MB 3.5" +0x0000, 0x0012 -Tracks (Cylinders) - - -40 - - -80 - - -80 - - -80 - - -80 - -Sectors Per Track/Cylinder - - -9 - - -15 - - -9 - - -18 - - -36 - -Total Sectors Per Disk - - -720 - - -2,400 - - -1,440 - - -2,880 - - -5,760 +mmh? \ No newline at end of file -- cgit v1.2.3-54-g00ecf