Writing Device Drivers

Register Identifiers

Machine or kadb(1M) internal registers are identified with the `<` command, followed by the register of interest. On SPARC machines, the following register names are recognized:

`.`	dot, the current location
`i0-7`	Input registers to current function
`o0-7`	Output registers for current function
`l0-7`	Local registers
`g0-7`	Global registers
`psr`	Processor Status Register
`tbr`	Trap Base Register
`wim`	Window Invalid Mask

For more information on how these registers are normally used, see the System V Application Binary Interface, SPARC Processor Supplement.

On x86 machines, the following register names are recognized:

`ebp`	Stack frame base register
`esp`	Stack pointer
`kesp`	Kernel stack pointer
`cs`	Code segment
`ds`	Data segment
`ss`	Stack segment
`eip`	Program pointer or instruction pointer
`efl`	Status flags register

Note -

The remaining examples in this chapter are for use on SPARC machines only. For specific register information relating to x86 machines, see the System V Application Binary Interface, x86 Processor Supplement.

The following command displays the PSR as a 4-byte hexadecimal value:

kadb[0]: <psr=X
                400cc3