Plan9 Tips

I want to documents some tips here, which are quite useful.

Copying files from Plan9 to Linux using floppy:

Create a 1.44 MB floppy image in linux, format it with FAT FS. Use it as 1st floppy disk in qemu.
In Plan9, use following commands to access it:
a:
cd /n/a:

Editing plan9.ini configuration file:

Type following command in Plan9,
9fat:
cd /n/9fat

Command to reboot / halt the system: reboot fshalt

For PC 386:
8c - is the C compiler
8a - is the assembler
8l - is the linker

One typically needs to add u.h and libc.h files as headers for C programs.

Important linker options for 8l are:
-H5 = Output is generated with ELF header
-l = Suppress default loading of startup files.
-T0x100000 = Loads Text section at 1MB

Default Entry symbol is _main

Default Plan9 kernel configuration for PC is pcf

Procedure for Compiling kernel:
cd /sys/src/9/pc
mk 'CONF=pcf'

To compile kernel in ELF format I modified /sys/src/9/pc/mkfile and added -H5 option to $(LD) command.