Solaris, by default, loads a 64-bit kernel during boot up, if the hardware supports it.
If, for whatever reason, you need to load Solaris in 32-bit mode, the following commands can be used to switch between the 32-bit and 64-bit kernels.
To boot into a 32-bit kernel:
# eeprom boot-file="kernel/unix"
To boot into a 64-bit kernel on Solaris x86:
# eeprom boot-file="kernel/amd64/unix"
To boot into a 64-bit kernel on Solaris SPARC:
# eeprom boot-file="kernel/sparcv9/unix"
To restore the default auto detected boot behavior:
# eeprom boot-file=""
If you are on the OBP (Open Boot PROM), you can use the
setenv command to set the ‘boot-file’ parameter. OBP is only available on SPARC Hardware.
OK> setenv boot-file kernel/unix
OK> setenv boot-file kernel/sparcv9/unix
A reboot is necessary to switch to the new kernel.