question about a HAL

bsunisol · Post by **bsunisol** » Thu Apr 12, 2007 7:58 am

hi,
i startet to began coding a simple osloader.
but without a concept at all. so i began to read and look for tutorials and documents. now i see that have to do a HAL first.
but i think a HAL with just in() out() disable_int() enable_int() is not really usable....

what would (or have) you put in your HAL,
or did you realise that with a complete different concept?

thanks
Uni_Sol

mystran · Post by **mystran** » Thu Apr 12, 2007 6:56 pm

Personally I'm so portable I don't have a HAL.

hendric · Post by **hendric** » Thu Apr 12, 2007 7:06 pm

If you want port your kernel to other platform , a HAL is necessary. For my design , I do not want my kernel porting from x86 to other platform so my HAL is simply implement pio / interrupt et.al. for convient usage. Whether to have a HAL or not depends on your purpose about portability , it's up to you

hendric · Post by **hendric** » Thu Apr 12, 2007 7:18 pm

And As my opinion , I do not think portability is necessary because I do not have to. I prefer deeply traiting features of a explicit platform such as x86. Like windows , to implement a top OS on a explicit platform is considered as a good idea, I think.

Alboin · Post by **Alboin** » Thu Apr 12, 2007 7:29 pm

I'm currently writing a HAL like layer for my OS entirely in assembly as it doesn't have to be portable. However, it is a very thin layer. For example, I have put_char written in assembly, but put_string, put_int, and printf, are all in C. I'm thinking that if it's written in C, then it is completely portable. Moreover, writing it in assembly makes it faster than C.

hendric · Post by **hendric** » Thu Apr 19, 2007 2:53 am

Alboin wrote:I'm currently writing a HAL like layer for my OS entirely in assembly as it doesn't have to be portable. However, it is a very thin layer. For example, I have put_char written in assembly, but put_string, put_int, and printf, are all in C. I'm thinking that if it's written in C, then it is completely portable. Moreover, writing it in assembly makes it faster than C.

Yea that's the same thing I did. In my design , I do not have an explicit HAL but a group of abstract of hardware functions such as "set interrupt entry", " Spin Lock" , "IO Port" et.al
I think it enough, and also do I think x86 is enough (with multi-cored

) . For other platform I prefer designing a new Operating System model to expose potention of the very architecture .
The same to x86-64 architecture , I do not believe it can be mainstream in future.