At Sun, 28 Sep 2025 07:45:56 -0500 Richard Owlett <[email protected]> wrote:
> > On 9/28/25 7:23 AM, Robert Heller wrote: > > At Sun, 28 Sep 2025 07:00:11 -0500 Richard Owlett <[email protected]> > > wrote: > > > >> > >> I may resurrect an former desktop machine as a trouble shooting aid. > >> I need to know the data bus width. > >> > >> I know the Debian version number is stored in /etc/debian_version . > >> > >> How do I find if the installed OS is 32 or 64 bit? > >> How do I discover the CPU's bus width? > > > > uname -a > > The output of > Linux debian12 6.1.0-28-amd64 #1 SMP PREEMPT_DYNAMIC Debian 6.1.119-1 > (2024-11-22) x86_64 GNU/Linux > Is clear. I *like*! This is a 64-bit kernel for a x86_64: Intel/AMD processor. > > > > > This will tell you the kernel version, including the bus width > > (Note: it is possible to install a 32-bit kernel on a 64-bit processor) > > That is the case of interest. I'm fairly certain that it has 32 bit > Debian installed. I need to know if the processor is 64 bit capable. > > > > cat /proc/cpuinfo > > > > This will tell you all about the processor(s). > > But as I replied to alain, I didn't find the data buss width clearly > identified. /proc/cpuinfo is not going to bother with that (it does not need to). It can be infered from the address bus with. If the number of address bits are <= 32 it is 32-bit, otherwise 64 bits. And one can always put the CPU model name into a search engine. I don't think any x86_64 processors actually provide 64 address lines, even though the processor does have 64-bit registers. Subsets are used as inputs to the MMU (virtual address bits) and the MMU only has a subset wired to the processor's pins (physical address bits). A 64-bit processor has more that 32 of each and a 32-bit processor generally has 32 (or fewer) (PAE i686's have more than 32-physical bits -- a sort of resurrection of 8086/80286 segmented memory address games). But the results of uname is difinitive. A 64-bit kernel won't run on a 32-bit CPU, although a 32-bit kernel will run on a 64-bit processor. So if the *kernel* is 64-bit, the processor is 64-bit. It is possible to have both 32-bit and 64-bit user-mode programms installed [on a 64-bit processor with a 64-bit kernel], if all of the proper libraries, including the /lib/ld-linus-*.so files. (I guess it is possible to install a 64-bit kernel and all 32-bit user-mode files, but why would one do that?) > > > > > > > > > >> > >> TIA > >> > >> > >> > > > > > -- Robert Heller -- Cell: 413-658-7953 GV: 978-633-5364 Deepwoods Software -- Custom Software Services http://www.deepsoft.com/ -- Linux Administration Services [email protected] -- Webhosting Services
