grub2

Simplest chainloading a boot manager

笑着哭i 提交于 2019-12-22 10:49:12
问题 In order to boot from flash memory drive we load disks using the BIOS interrupt 13h in real mode with specifying the disk 0x80. Another disks should be accessed by 0x81, 0x82... as mentioned over this link I am trying to make my simple GRUB . My very first step is to boot from flash memory drive (Load MBR into 0x7C00 and print a message as a proof of correct boot) and read the my main HDD (which I assume it is numbered 0x81 and that the first 15 sectors are needed for booting) again into

Simplest chainloading a boot manager

依然范特西╮ 提交于 2019-12-05 18:44:31
In order to boot from flash memory drive we load disks using the BIOS interrupt 13h in real mode with specifying the disk 0x80. Another disks should be accessed by 0x81, 0x82... as mentioned over this link I am trying to make my simple GRUB . My very first step is to boot from flash memory drive (Load MBR into 0x7C00 and print a message as a proof of correct boot) and read the my main HDD (which I assume it is numbered 0x81 and that the first 15 sectors are needed for booting) again into 0x7C00. I suppose that this naive idea should drop me into my main HDD's bootloader, but it is not as

Ubuntu grub2介绍

淺唱寂寞╮ 提交于 2019-12-03 07:42:25
Ubuntu grub2简介   从Ubuntu 9.10起,grub2就已经是默认的BootLoader了。这里简要说要Ubuntu的grub2和其他发行版不一样的地方。   对于所有的OS启动项,CentOS全都显示在一个grub选择界面,显得非常拥挤,而Ubuntu这里就使用了一个Submenu的概念,将kernel版本最高的OS启动项放在最顶端名为“Ubuntu”的选项中,其他的版本都放在一个名为“Advanced options for Ubuntu”中,这个就是前面说到的Submenu子菜单。进入子菜单后,就可以手动选择你需要的版本了。这里注意,每个版本都提供了普通版和recover mode两种选择。   grub选择界面:   grub配置文件如下: …… # OS启动版本选择 set default="0" fi submenu 'Advanced options for Ubuntu' $menuentry_id_option 'gnulinux-advanced-f7627d97-02da-4145-af58-0fe730f276b2' { menuentry 'Ubuntu, with Linux 3.13.0-24-generic' --class ubuntu --class gnu-linux --class gnu --class os

Linux Deepin 2014.2(Ubuntu 14.04)忘记密码修复办法

最后都变了- 提交于 2019-12-02 05:46:29
尝试遍了各种Linux发行版,半年前成为深度Linux的脑残粉,脑残至今。。。 Deepin本来就是基于Ubuntu,所以直接上手无压力,本地化和UI都是极好的 -_-!! Linux Deepin 2014.2基于Ubuntu 14.04 TLS开发。该版本系统已经改由Grub2引导,昨天把系统玩坏了,愁死人,今天终于搞定,准备记篇博客 ,顺便讲解下新版grub2怎样用root权限启动。 以下演示以Linux Deepin 2014.2截图,Ubuntu类似(我猜的!) 1. 首先开机选择“Advanced options for *****”这一行按回车,然后选中最后是“(recovery mode)”这一行按“E”进入编辑页面,如图: 2. 修改上图中红圈中的ro为rw,使文件系统可读可写,然后按Ctrl+x或F10启动。 3. 来到下面的选单,选“Drop to root shell prompt”即可获得root shell。 4.然后就可以淡定的执行“passwd + 要修改密码的用户名”,修改密码后“shutdown -r now”重启正常启动即可。 【注意】 Ubuntu的默认root密码是随机的,每次开机都有一个新的root密码。可以在终端输入命令“sudo passwd”,然后验证当前用户的密码后修改root密码。 但是我个人不建议这样做

Debian下面修改Grub2的默认启动顺序

我与影子孤独终老i 提交于 2019-12-01 23:27:30
笔记本安装了Debian与Windows 7双系统,默认启动是linux,刚开始用linux不怎么习惯。所以想把启动顺序修改为Windows优先。 上网找了一下修改的方法 。修改grub2默认启动顺序 vi /etc/default/grub 把“GRUB_DEFAULT=0”里面的数字0改为你想让他默认启动的os,数字从0开始由屏幕上第一个os往下数。 修改完保存退出, 运行:update-grub http://wanghuiwl320.blog.163.com/blog/static/2159881120121101321245/ 来源: oschina 链接: https://my.oschina.net/u/100399/blog/49909

Creating a simple multiboot kernel loaded with grub2

爱⌒轻易说出口 提交于 2019-11-29 02:27:10
I'm trying to follow the instructions here to build a simple OS kernel: http://mikeos.sourceforge.net/write-your-own-os.html Except, instead of booting from a floppy, I want to create a grub-based ISO image and boot a multiboot CD in the emulator. I've added the following to the source listed at that page, for the multiboot header: MBALIGN equ 1<<0 ; align loaded modules on page boundaries MEMINFO equ 1<<1 ; provide memory map FLAGS equ MBALIGN | MEMINFO ; this is the Multiboot 'flag' field MAGIC equ 0x1BADB002 ; 'magic number' lets bootloader find the header CHECKSUM equ -(MAGIC + FLAGS) ;