EDKII HTTP Boot

什麼是 HTTP Boot? 官方網站說明 https://github.com/tianocore/tianocore.github.io/wiki/HTTP-Boot
裡面有提到 UEFI , EDK II 以及 HTTP Boot 先來了解一下.

• UEFI
  Extensible Firmware Interface (EFI) 的功能就類似傳統 BIOS ,他是 OS 與硬體之間溝通介面. 不過相較於傳統的 BIOS EFI 他的架構更模組化,功能更強大.EFI 的架構是由 Intel 提出的, 目前是交由 Unified EFI Forum 來管理.也就是我們現在所稱的 Unified Extensible Firmware Interface (UEFI)
• EDK II
  EDK II is a modern, feature-rich, cross-platform firmware development environment for the UEFI and Platform Initialization(PI) specifications.
  EDK II is open source, using a BSD(FreeBSD) license.
  EDK II is a development code base for creating UEFI drivers, applications and firmware images.
• HTTP Boot
  傳統的網卡 ROM 裡面存放了一些基本的網路協定如: Internet Protocol (IP), User Datagram Protocol (UDP), Dynamic Host Configuration Protocol (DHCP) 以及 Trivial File Transfer Protocol (TFTP) 透過這一些協定使得網卡在系統開機後就可以直接進行網路存取,進一步取得開機檔案與程序,這就是所謂的 PXE .
  新的 iPXE 就支援比較多的開機模式,可以從 web server via HTTP , iSCSI SAN , Fibre Channel SAN via FCoE , AoE SAN , wireless network , wide-area network , infiniband network.
  iPXE 可以直接把它燒錄到 網卡 ROM 內,或是透過一般的 PXE ROM 開機,但後續的工作環境透過 iPXE 來運作並搭配他的 Script + command line 命令列指令來操作.

  EDK II 有支援從 HTTP Boot 開機的選項,同時支援 IPv4 與 IPv6 的環境.

設定參考文件: https://github.com/tianocore-docs/Docs/raw/master/White_Papers/EDKIIHttpBootGettingStartedGuide_0_8.pdf

EDK II HTTP Boot 需要下列服務 DHCP (v4 或 v6) , DNS , Web Server .

1. HTTP Boot 測試所需服務都架設在 CentOS 6.8 x68_64 ( IPv4: 192.6.1.1/24 , IPv6: 3ffe:501:ffff:100::1/64 )
2. 還需要有一台有支援 HTTP Boot 開機的系統.

設定 DHCPv4

[root@localhost ~]# vi /etc/dhcp/dhcpd.conf 
#ddns-update-style interim;
ddns-update-style none;
ignore client-updates;
 
allow booting;
allow bootp;

subnet 192.6.1.0 netmask 255.255.255.0 {
        range 192.6.1.50 192.6.1.250;
        option broadcast-address 192.6.1.255;
        option subnet-mask 255.255.255.0;
        option vendor-class-identifier “HTTPClient”;
        option bootfile-name “http://192.6.1.1/EFI/Shell.efi”;
}

DHCP v4 設定需注意的地方如下,開機檔案請依據實際位置設定.

1. option vendor-class-identifier “HTTPClient”;
2. bootfile-name “http://192.6.1.1/EFI/Shell.efi”;

設定 DHCPv6

[root@localhost ~]# vi /etc/dhcp/dhcpd6.conf
default-lease-time 600;
max-lease-time 7200;
log-facility local7;
option dhcp6.vendor-class code 16 = {integer 32, integer 16, string};
subnet6 3ffe:501:ffff:100::1/64 {
        range6 3ffe:501:ffff:100::100 3ffe:501:ffff:100::200
        option dhcp6.vendor-class 0 0 “HTTPClient”;
        option dhcp6.bootfile-url “http://3ffe:501:ffff:100::1/EFI/Shell.efi”;
}

DHCP v6 設定需注意的地方如下,開機檔案請依據實際位置設定.

1. option dhcp6.vendor-class 0 0 “HTTPClient”;
2. option dhcp6.bootfile-url “http://3ffe:501:ffff:100::1/EFI/Shell.efi”;

DNS

如果你跟我一樣只有使用到 IP ,DNS 為非必要.

Web Server (Apache)

RHEL 預設的 Web Server 為 Apache,須確認服務已開啟.

[root@localhost ~]# service httpd status
httpd (pid 3688) is running...

整合 PXE 環境

可能你的環境已經有舊的 Legacy PXE ,我們可以把 UEFI PXE, HTTP Boot 都整合在同一台伺服器.只需要修改 DHCP 的設定即可.

• DHCP IPv4

  [root@localhost ~]# cat /etc/dhcp/dhcpd.conf 
  #ddns-update-style interim;
  ddns-update-style none;
  ignore client-updates;
   
  allow booting;
  allow bootp;
  
  subnet 192.6.1.0 netmask 255.255.255.0 {
          range 192.6.1.50 192.6.1.250;
          option broadcast-address 192.6.1.255;
          option subnet-mask 255.255.255.0;
   
          if option arch = 00:010 {
             option vendor-class-identifier “HTTPClient”;
             option bootfile-name “http://192.6.1.1/EFI/Shell.efi”;
          } else {
              next-server 192.6.1.1;
              filename "linux-install/pxelinux.0";
          }
  }
  

  重點就是 if option arch = 00:010 ,如果 PXE Client 是透過 x64 uefi boot from http ( Architecture Type : 0x00:0x10 ) 就使用 Shell.efi 為開機檔案,要不然就是採傳統的開機 pxelinux.0 .

• DHCP IPv6

  [root@localhost ~]# cat /etc/dhcp/dhcpd6.conf
  default-lease-time 600;
  max-lease-time 7200;
  log-facility local7;
  option dhcp6.vendor-class code 16 = {integer 32, integer 16, string};
  subnet6 3ffe:501:ffff:100::1/64 {
  range6 3ffe:501:ffff:100::100 3ffe:501:ffff:100::200
  
          if option dhcp6.arch-type = 00:010 {
          option dhcp6.vendor-class 0 0 “HTTPClient”;
          option dhcp6.bootfile-url “http://3ffe:501:ffff:100::1/EFI/Shell.efi”;
          } else  {
          option dhcp6.bootfile-url “http://3ffe:501:ffff:100::1/EFI/grub64.efi”;
          }
  }
  

  重點就是 if option dhcp6.arch-type = 00:010 (如果 isc-dhcp 版本為 4.4 參數需改成 dhcp6.client-arch-type) ,如果 PXE Client 是透過 x64 uefi boot from http ( Architecture Type : 0x00:0x10 ) 就使用 Shell.efi 為開機檔案,要不然就是採 UEFI 的開機檔 grub64.efi .

• DHCP 支援與 HTTP Boot 相關的 Architecture Type 如下:
  • 0x00:0x0f – x86 uefi boot from http
  • 0x00:0x10 – x64 uefi boot from http
  • 0x00:0x11 – ebc boot from http
  • 0x00:0x12 – arm uefi 32 boot from http
  • 0x00:0x13 – arm uefi 64 boot from http
  • 0x00:0x14 – pc/at bios boot from http
  • 0x00:0x17 – arm uboot 32 boot from http
  • 0x00:0x18 – arm uboot 64 boot from http
  • 0x00:0x1a – RISC-V 32-bit UEFI boot from http
  • 0x00:0x1c – RISC-V 64-bit UEFI boot from http
  • 0x00:0x1e – RISC-V 128-bit UEFI boot from http

  使用的開機檔案會有不同.

  其他關於 DHCP 支援的 Architecture Type.詳細請參考 整合性的 PXE 環境設定 https://benjr.tw/16194 說明.

遇過的問題
作業系統為 CentOS 8 ISC DHCP v4.4
無法啟動 dhcpd6 服務,透過 # journalctl -xe 顯示以下的錯誤訊息.

no option named arch-type in space dhcp6

檢視官方文件 https://kb.isc.org/docs/isc-dhcp-44-manual-pages-dhcp-options#standard-dhcpv6-options 說明 dhcp6.arch-type 參數需改成 dhcp6.client-arch-type .