Import Dev86src-0.16.18.tar.gzv0.16.18

1 files changed, 82 insertions, 0 deletions

diff --git a/bootblocks/sysboot16.s b/bootblocks/sysboot16.s
new file mode 100644
index 0000000..baac806
--- /dev/null
+++ b/bootblocks/sysboot16.s
@@ -0,0 +1,82 @@
+
+! The master boot sector will have setup a stack,
+! this is normally at 0:7c00 down.
+! DS, SS, CS and ES will all have value 0 so the execution address is 0:7c00
+! On entry the register SI will be pointer to the partition entry that
+! this sector was loaded from, DL is the drive.
+
+! Also if it's a standard Master boot DH will be the head, CX will be the
+! sector and cylinder, BX=7C00, AX=1, DI=7DFE, BP=SI. There's a reasonable
+! chance that this isn't true though.
+
+! The Master boot itself will have been loaded and run at $07c00
+! The BIOS must have setup a stack because interrupts are enabled
+! Little else can be assumed because DOS doesn`t assume anything either
+
+sysboot_start:
+j codestart
+nop		! DOS appears to _require_ this to identify an MSDOS disk!!
+
+.blkb sysboot_start+3-*
+public dosfs_stat
+dos_sysid:	.ascii "LINUX"	! System ID
+		.byte 0,0,0
+dosfs_stat:
+dos_sect:	.blkw 1		! Sector size
+dos_clust:	.blkb 1		! Cluster size
+dos_resv:	.blkw 1		! Res-sector
+dos_nfat:	.blkb 1		! FAT count
+dos_nroot:	.blkw 1		! Root dir entries
+dos_maxsect:	.blkw 1		! Sector count (=0 if large FS)
+dos_media:	.blkb 1		! Media code
+dos_fatlen:	.blkw 1		! FAT length
+dos_spt:	.blkw 1		! Sect/Track
+dos_heads:	.blkw 1		! Heads
+dos_hidden:	.blkw 2		! Hidden sectors
+
+! Here down is DOS 4+ and probably not needed for floppy boots.
+
+dos4_maxsect:	.blkw 2		! Large FS sector count
+dos4_phy_drive:	.blkb 1		! Phys drive
+.blkb 1		! Reserved
+.blkb 1		! DOS 4
+
+floppy_temp:
+dos4_serial:	.blkw 2		! Serial number
+dos4_label:	.blkb 11	! Disk Label (DOS 4+)
+dos4_fattype:	.blkb 8		! FAT type
+
+!
+! This is where the code will be overlaid, the default is a hang
+.blkb sysboot_start+0x3E-*
+public codestart
+codestart:
+  j	codestart
+
+! Partition table
+public bootblock_magic
+
+.blkb sysboot_start+0x1BE-*
+partition_1:
+.blkb 8			! IN,SH,SS,ST,OS,EH,ES,ET
+.blkw 2			! Linear position (0 based)
+.blkw 2			! Linear length
+.blkb sysboot_start+0x1CE-*
+partition_2:
+.blkb 8			! IN,SH,SS,ST,OS,EH,ES,ET
+.blkw 2			! Linear position (0 based)
+.blkw 2			! Linear length
+.blkb sysboot_start+0x1DE-*
+partition_3:
+.blkb 8			! IN,SH,SS,ST,OS,EH,ES,ET
+.blkw 2			! Linear position (0 based)
+.blkw 2			! Linear length
+.blkb sysboot_start+0x1EE-*
+partition_4:
+.blkb 8			! IN,SH,SS,ST,OS,EH,ES,ET
+.blkw 2			! Linear position (0 based)
+.blkw 2			! Linear length
+
+.blkb sysboot_start+0x1FE-*
+bootblock_magic:
+.word 0xAA55