linux - dmidecode 从哪里获取 SMBIOS 表？

Question

我一直有这个问题，在阅读手册页和在线搜索后没有得到答案。有知道这方面知识的 friend 请评论。

我理解SMBIOS表或DMI表是dmidecode定位和解析的。但是它是从哪里得到的呢？在Linux中是文件格式吗？

Answer 1

看起来它来自/dev/mem

root@aw42e ~]# strace -F -e open dmidecode -t 17
   <snip>
    open("/sys/firmware/efi/systab", O_RDONLY) = -1 ENOENT (No such file or directory)
    open("/proc/efi/systab", O_RDONLY)      = -1 ENOENT (No such file or directory)
    open("/dev/mem", O_RDONLY)              = 3
    SMBIOS 2.5 present.

    open("/dev/mem", O_RDONLY)              = 3
    Handle 0x0016, DMI type 17, 27 bytes
    Memory Device
<snip>

/dev/mem 被描述为

mem is a character device file that is an image of the main memory of the computer. It may be used, for example, to examine (and even patch) the system. Byte addresses in mem are interpreted as physical memory addresses.

所以要回答，它包含在/dev/mem

我正在搜索更多信息，但我假设内核在启动时将 DMI 表插入内存 - 来自 man dmidecode

As you run it, dmidecode will try to locate the DMI table. If it succeeds, it will then parse this table and display a list of records like this one: