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author | Frans Kaashoek <[email protected]> | 2011-08-15 12:02:59 -0400 |
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committer | Frans Kaashoek <[email protected]> | 2011-08-15 12:02:59 -0400 |
commit | c60a3551c2dba29006f5d7917308281e47fa5fef (patch) | |
tree | 3fad525469c88a1521220ff8d0468dddbdb47af5 /entry.S | |
parent | c95ce31c5978bd43e1f0d34e51a4e3d7bcc41b14 (diff) | |
download | xv6-labs-c60a3551c2dba29006f5d7917308281e47fa5fef.tar.gz xv6-labs-c60a3551c2dba29006f5d7917308281e47fa5fef.tar.bz2 xv6-labs-c60a3551c2dba29006f5d7917308281e47fa5fef.zip |
Separate more clearly bootloader from xv6 by renaming multiboot.S to entry.S etc.
Maybe the string boot shouldn't appear in xv6 code?
Diffstat (limited to 'entry.S')
-rw-r--r-- | entry.S | 60 |
1 files changed, 60 insertions, 0 deletions
@@ -0,0 +1,60 @@ +# Multiboot header, for multiboot boot loaders like GNU Grub. +# http://www.gnu.org/software/grub/manual/multiboot/multiboot.html +# +# Using GRUB 2, you can boot xv6 from a file stored in a +# Linux file system by copying kernel or kernelmemfs to /boot +# and then adding this menu entry: +# +# menuentry "xv6" { +# insmod ext2 +# set root='(hd0,msdos1)' +# set kernel='/boot/kernel' +# echo "Loading ${kernel}..." +# multiboot ${kernel} ${kernel} +# boot +# } + +#include "asm.h" +#include "memlayout.h" +#include "mmu.h" + +#define STACK 4096 + +# Multiboot header. Data to direct multiboot loader. +.p2align 2 +.text +.globl multiboot_header +multiboot_header: + #define magic 0x1badb002 + #define flags (1<<16 | 1<<0) + .long magic + .long flags + .long (-magic-flags) + .long multiboot_header # beginning of image + .long multiboot_header + .long edata + .long end + .long multiboot_entry + +# Multiboot entry point. Machine is mostly set up. +.globl multiboot_entry +multiboot_entry: + movl $(V2P_WO(bootpgdir)), %eax + movl %eax, %cr3 + # Turn on paging. + movl %cr0, %eax + orl $(CR0_PE|CR0_PG|CR0_WP), %eax + movl %eax, %cr0 + + # now switch to using addresses above KERNBASE + # call addresses are pc-relative so we jump though this hoop: + mov $relocated, %eax + jmp *%eax +relocated: + # Set up the stack pointer and call into C. + movl $(stack + STACK), %esp + call main +spin: + jmp spin + +.comm stack, STACK |