如何创建专用的“保留BIOS引导区”分区

recently I think I deleted some important Ubuntu files because of using the wrong flag for sudo rm commands which may have caused it to delete some key files rendering it unable to boot.

So, I created a live USB of Ubuntu 20.04 LTS which was the OS on my system in an attempt to repair the damage by "reinstalling Ubuntu while keeping maximum files and software"

但是,每当我尝试自行安装时,都会出现此错误:-

The partition table format in use on your disk requires you to create a separate partition for boot loader code..... partition should be marked as a "Reserved BIOS boot area" and should be atleast 1Mb.

然后,Ans警告我不要继续,以免我希望系统出现故障。所以我很困惑为什么它要我做这样的事情,因为它要做的就是覆盖以前存在的任何分区。这是它的样子:-

Device                   Size        Mount Point    System
------                   -----      ------------    ------
/dev/sda      
free space    1Mb        
/dev/sda1 (type=fat32)     536Mb      /boot/efi     
/dev/sda2 (type=ext4)      999665Mb   /             Ubuntu 20.04 LTS 
free space                 0Mb
我不明白在线指南显示了如何做到这一点。我担心系统会进一步崩溃或根本无法启动。谁能建议/教我如何创建错误请求的分区?

另外,为什么不简单地覆盖现有分区,因为它们已经存在?请注意,我不想双重引导,只是为了修复损坏的操作系统。