cut bootmain to 1 sheet

bootmain.c

-// This a dirt simple boot loader, whose sole job is to boot
-// an elf kernel image from the first IDE hard disk.
-//
-// DISK LAYOUT
-//  * This program(boot.S and main.c) is the bootloader.  It should
-//    be stored in the first sector of the disk.
-//
-//  * The 2nd sector onward holds the kernel image.
-//
-//  * The kernel image must be in ELF format.
-//
-// BOOT UP STEPS
-//  * when the CPU boots it loads the BIOS into memory and executes it
-//
-//  * the BIOS intializes devices, sets up the interrupt routines, and
-//    reads the first sector of the boot device(e.g., hard-drive)
-//    into memory and jumps to it.
-//
-//  * Assuming this boot loader is stored in the first sector of the
-//    hard-drive, this code takes over...
-//
-//  * control starts in bootloader.S -- which sets up protected mode,
-//    and a stack so C code then run, then calls cmain()
-//
-//  * cmain() in this file takes over, 
-//    reads in the kernel and jumps to it.
-
-//PAGEBREAK!
+// Boot loader.
+// 
+// The BIOS loads boot sector (bootasm.S) from sector 1 of the disk
+// into memory and executes it.  The boot sector puts the processor
+// in 32-bit mode and calls cmain below, which loads an ELF kernel
+// image from the disk starting at sector 2 and then jumps to the
+// kernel entry routine.
+
 #include "types.h"
 #include "elf.h"
 #include "x86.h"