Which C language and Graphic library should be use to write OS independent program? [closed]_问答_开发者

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I am trying to write a program which I want to run just before booting up the system like the Setup program of Windows XP. The problem is that I cannot figure out which version of C/C++ programming language should be use. Because as far as I know about the many versions of C language they only works in DOS, Windows and Linux. Or is there any way to write the program in the Visual C++ or Turbo C that can run without any OS.

My next question is that which Graphics library can be use in that C language to create and display Images and Shapes on screen, Setting Background color etc.

I read an article on Windows in Wikipedia and I found that it is written on C++. So I thought that I can a开发者_运维问答lso write similar type of program in C++ without switching to Assembly language.

You want to write a program that runs directly off boot, with no OS loaded? Sorry, but if you need to ask which language to use, you have a learning curve ahead of you that's so steep that you ought to consider lowering your ambitions considerably for a first effort.

In the bad old days when space was at a premium, bootloaders were written in raw assembler. Today most of the functionality is written in C (or perhaps C++), but one still needs to go to assembler for the very earliest stages that take over from the BIOS, loads more code from disk than the single sector BIOS gives you, and puts the processor into protected mode so it can access more than 1 MB of RAM.

The choice between C and C++ is mostly up to preferences. C++ tends to require a somewhat more complex assembly intro in order to set up its run-time environment as the compiled code expects to find it. In either case, you won't have much in the way of standard libraries available. No malloc/free/new/delete unless you implement them yourself, for example.

No matter what the language, you will need to customize the linking phase much beyond what an off-the-shelf compiler toolchain will do for you with a simple command.

If you're using an x86 machine, you are going to have to learn how to work with either the default VGA buffer, or possibly VBE mode buffer if you want higher-resolution graphics. Most of this will have to be setup through calling BIOS interrupts or using MMIO ports dedicated to controlling the VGA buffer. In either case, this is going to have to be a mixture of assembly and C ... you can't really take advantage of C++ in this instance, since you will not have the use of a OS runtime that typically provides support for many C++-specific language features like exceptions, etc. If you want those types of features, you're going to have to setup the runtime yourself.

Here is a great site for information on the VGA registers that can be accessed through x86 MMIO: http://www.osdever.net/FreeVGA/home.htm

C/C++ does not matter as each system will compile it into the correct machine code for that machine. I can't remember the exact steps, but you're definitely going to have to mess around with copying your code into boot sector, etc.

You will inevitably have to write a little assembly language to be able to write something which boots before the OS. You'll have to write a boot-loader for one thing.

As to a graphics library, you will pretty much have to roll your own if you want graphics, because most libraries use at least some capabilities of an underlying operating system, no mater how cross-platform they are. You'll notice, for example, that the Windows setup program is all text until it boots into the Windows that's being set up for the first time.

As you mentioned yourself, you need to write a boot loader and that is, after compiling your boot loader you have to install it somehow (I'm not so sure about this part), but that usually involves copying it to a certain location of your hard disk, referenced by the master boot record.

As for graphics (or better say graphics card), as well as any other device that you want to interact with at boot time, you simply need to load their driver. So, in principle, your boot loader starts running, loads a bigger portion of itself into memory and once that is done, it start loading the drivers and starts working (similar to how an operation system boots, but much much simpler). The drivers are usually very limited but very generic drivers that you either have to write yourself or find on the internet.