| # x86 bootblock used in migration test |
| # repeatedly increments the first byte of each page in a 100MB |
| # range. |
| # Outputs an initial 'A' on serial followed by repeated 'B's |
| # |
| # Copyright (c) 2016 Red Hat, Inc. and/or its affiliates |
| # This work is licensed under the terms of the GNU GPL, version 2 or later. |
| # See the COPYING file in the top-level directory. |
| # |
| # Author: dgilbert@redhat.com |
| |
| |
| .code16 |
| .org 0x7c00 |
| .file "fill.s" |
| .text |
| .globl start |
| .type start, @function |
| start: # at 0x7c00 ? |
| cli |
| lgdt gdtdesc |
| mov $1,%eax |
| mov %eax,%cr0 # Protected mode enable |
| data32 ljmp $8,$0x7c20 |
| |
| .org 0x7c20 |
| .code32 |
| # A20 enable - not sure I actually need this |
| inb $0x92,%al |
| or $2,%al |
| outb %al, $0x92 |
| |
| # set up DS for the whole of RAM (needed on KVM) |
| mov $16,%eax |
| mov %eax,%ds |
| |
| mov $65,%ax |
| mov $0x3f8,%dx |
| outb %al,%dx |
| |
| # bl keeps a counter so we limit the output speed |
| mov $0, %bl |
| mainloop: |
| # Start from 1MB |
| mov $(1024*1024),%eax |
| innerloop: |
| incb (%eax) |
| add $4096,%eax |
| cmp $(100*1024*1024),%eax |
| jl innerloop |
| |
| inc %bl |
| jnz mainloop |
| |
| mov $66,%ax |
| mov $0x3f8,%dx |
| outb %al,%dx |
| |
| jmp mainloop |
| |
| # GDT magic from old (GPLv2) Grub startup.S |
| .p2align 2 /* force 4-byte alignment */ |
| gdt: |
| .word 0, 0 |
| .byte 0, 0, 0, 0 |
| |
| /* -- code segment -- |
| * base = 0x00000000, limit = 0xFFFFF (4 KiB Granularity), present |
| * type = 32bit code execute/read, DPL = 0 |
| */ |
| .word 0xFFFF, 0 |
| .byte 0, 0x9A, 0xCF, 0 |
| |
| /* -- data segment -- |
| * base = 0x00000000, limit 0xFFFFF (4 KiB Granularity), present |
| * type = 32 bit data read/write, DPL = 0 |
| */ |
| .word 0xFFFF, 0 |
| .byte 0, 0x92, 0xCF, 0 |
| |
| gdtdesc: |
| .word 0x27 /* limit */ |
| .long gdt /* addr */ |
| |
| /* I'm a bootable disk */ |
| .org 0x7dfe |
| .byte 0x55 |
| .byte 0xAA |
