diff --git a/docs/develop/kernel/arch/sparc/openboot.txt b/docs/develop/kernel/arch/sparc/openboot.txt new file mode 100644 index 0000000000..7a5aab336f --- /dev/null +++ b/docs/develop/kernel/arch/sparc/openboot.txt @@ -0,0 +1,53 @@ +Openboot is Sun's implementation of Open Firmware. So we should be able to share +a lot of code with the PowerPC port. There are some differences however. + +Executable format +================= + +PowerPC uses COFF. Sparc uses a.out, which is a lot simpler. According to the +spec, some fields should be zeroed out, but they say implementation may chose +to allow other values, so it's possible a standard a.out file would work as +well. + +Openfirmware prompt +=================== + +To get the prompt on display, use STOP+A at boot until you get the "ok" prompt. +On some machines, if no keyboard is detected, the ROM will assume it is set up +in headless mode, and will expect a BREAK+A on the serial port. + +STOP+N resets all variables to default values (in case you messed up input or +output, for example). + +Useful commands +=============== + +Disable autoboot to get to the openboot prompt and stop there +------------------------------------------------------------- + +setenv auto-boot? false + +Configuring for keyboard/framebuffer io +--------------------------------------- + +setenv screen-#columns 160 +setenv screen-#rows 49 +setenv output-device screen:r1920x1080x60 +setenv input-device keyboard + +Configuring openboot for serial port +------------------------------------ + +setenv ttya-mode 38400,8,n,1,- +setenv output-device ttya +setenv input-device ttya +reset + +Boot from network +----------------- + +rarp: +boot net + +dhcp: +boot net:dhcp