Introduction

Beware mortal soul, building a kernel can be difficult enough. Snowflake likes to throw in a bunch more curlies into the process, so dun be too sad if it doesn't quite work.

Supported Host Systems

These have been confirmed working as at revision 208:

• linux 64-bit (32-bit should work)
• mac os x 10.5/10.6 with cross-compiler (requires XCode 3.2.2)
• freebsd 32-bit

Details

Some pre-requisite software:

• gcc/binutils with support for i386-elf (need multilib support on 64-bit)
• mkisofs
• make/patch/sed/grep/useful tools like that

Once all that is installed, it should be as simple as typing make from the root of the project source.

Mac OS X

Building snowflake itself is almost as easy as building for everything else. It's just building the prerequisites first!

1. build a cross compiler
2. build mkisofs

Building a Cross Compiler

These steps are a modified version of http://m3os.wordpress.com/2009/03/29/tutorial-building-an-i386-elf-cross-compiler-and-binutils-on-os-x/. It is also assumed you have the latest XCode suite installed.

Prerequisites:

1. gmp: http://ftp.gnu.org/pub/gnu/gmp/gmp-4.3.2.tar.bz2
2. mpfr: http://ftp.gnu.org/pub/gnu/mpfr/mpfr-2.4.2.tar.bz2
3. mpc: http://www.multiprecision.org/mpc/download/mpc-0.8.1.tar.gz

These can be built with typical tar xjf xxx.tar.bz2; cd xxx; ./configure; make; sudo make install (or tar zxf xxx.tar.gz).

Then building your cross compiler:

1. mkdir crosstools && cd crosstools
2. curl http://ftp.gnu.org/pub/gnu/binutils/binutils-2.20.1.tar.bz2 > binutils.tar.bz2
3. tar xjf binutils.tar.bz2
4. curl http://ftp.gnu.org/pub/gnu/gcc/gcc-4.5.0/gcc-4.5.0.tar.bz2 > gcc.tar.bz2
5. tar xjf gcc.tar.bz2
6. sudo mkdir /usr/local/cross
7. sudo chmod 777 /usr/local/cross
8. mkdir build-binutils && cd build-binutils
9. ../binutils-2.20.1/configure --target=i386-elf --prefix=/usr/local/cross
10. make -j 3 all
11. find . -name 'Makefile.in' | xargs sed -i -e 's/-Werror//g'
12. find . -name 'Makefile' | xargs sed -i -e 's/-Werror//g'
13. make all install
14. cd ..
15. mkdir build-gcc && cd build-gcc
16. ../gcc-4.5.0/configure --target=i386-elf --prefix=/usr/local/cross --with-gnu-as --with-gnu-ld --disable-libssp --enable-languages=c
17. make all install

The find/sed magic is to address an issue where it complains about format strings warning.

Building mkisofs

Cdrtools can be obtained from http://cdrecord.berlios.de/old/private/cdrecord.html. The package ftp://ftp.berlios.de/pub/cdrecord/alpha/cdrtools-beta.tar.gz seems to work fine. Simply skip the configure step, and run make; sudo make install. It installs the tools in a weird location, so fix that too:

• sudo mv /opt/schilly/bin/* /usr/bin/

Building Snowflake

Once you have your cross compiler and mkisofs, the steps are (if you used a different path to the instructions above, use that here instead):

1. export TOOLSPREFIX=/usr/local/cross/bin
2. make

If all goes well, you should have a snowflake.native which is the kernel. If everything goes really well, you should also have a snowflake.iso to boot!