I'd like to create a new operating system for x86 PC computers. I'd like it to be 64-bit but possibly run as 32-bit as well.

I have these kinds of questions:

What kinds of things do you start working on first? Knowing where to start in writing your own operating system seems to me to be a tricky subject, so I am interested in your input.

Generally how to go about making your own 32-bit/64-bit operating system, or good resources that mention useful information about going about writing your own operating system for x86 computers. I don't care how old sources are as long as they are still relevant and useful to what I am doing.

I know that I will want it to have kernel drivers that access peripheral hardware directly. Where should I look for advice and documentation for programming and understanding the interface to peripheral hardware the operating system will communicate with? I will need to understand how the operating system will receive input and interact with keyboards, mice, computer monitors, hard drives, USB, etc. etc. This is probably the area I know least about.

I have the Intel instruction set manuals and have been getting more familiar with assembly programming, so the CPU side of things is what I know the most about.

At this point I'm thinking that I'd like to implement the Linux system calls within my operating system so that programs that run on Linux can run on my operating system. I want my operating system to use the ELF binary format. I wonder what obstacles I have to overcome to achieve this Linux compatibility. Are the main things implementing the system calls that Linux provides, and using the ELF format? What else?

I am also interested in people's thoughts about why it might not be a good idea to make your own operating system, and why it is a good idea to make your own operating system.

Thank you for any input.