Imbus/xv6-riscv-kernel
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no /* */ comments

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rsc 2006-09-06 17:50:20 +00:00
parent 9e9bcaf143
commit f552738889
22 changed files with 347 additions and 371 deletions
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57
bootmain.c
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@ -1,34 +1,31 @@
#include "types.h"
#include "elf.h"
#include "x86.h"
/**********************************************************************
* 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 of 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.
**********************************************************************/
// 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 of 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.
#define SECTSIZE 512
#define ELFHDR ((struct elfhdr*) 0x10000) // scratch space
@ -62,7 +59,7 @@ bad:
outw(0x8A00, 0x8A00);
outw(0x8A00, 0x8E00);
while(1)
/* do nothing */;
;
}
// Read 'count' bytes at 'offset' from kernel into virtual address 'va'.
@ -96,7 +93,7 @@ waitdisk(void)
{
// wait for disk reaady
while((inb(0x1F7) & 0xC0) != 0x40)
/* do nothing */;
;
}
void