Using the regs Command

The regs command lets you print the value of all the registers.

Here is the syntax for the regs command:

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regs [-f][-F]

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--f includes floating point registers (single precision). --F includes floating point registers (double precision); this is a SPARC only option.

For SPARC:

---

dbx[13] regs -F
current thread: t@1
current frame:  [1]
g0-g3    0x00000000 0x0011d000 0x00000000 0x00000000
g4-g7    0x00000000 0x00000000 0x00000000 0x00020c38
o0-o3    0x00000003 0x00000014 0xef7562b4 0xeffff420
o4-o7    0xef752f80 0x00000003 0xeffff3d8 0x000109b8
l0-l3    0x00000014 0x0000000a 0x0000000a 0x00010a88
l4-l7    0xeffff438 0x00000001 0x00000007 0xef74df54
i0-i3    0x00000001 0xeffff4a4 0xeffff4ac 0x00020c00
i4-i7    0x00000001 0x00000000 0xeffff440 0x000108c4
y        0x00000000
psr      0x40400086
pc       0x000109c0:main+0x4    mov     0x5, %l0
npc      0x000109c4:main+0x8    st      %l0, [%fp - 0x8]
f0f1     +0.00000000000000e+00
f2f3     +0.00000000000000e+00
f4f5     +0.00000000000000e+00
f6f7     +0.00000000000000e+00
... 

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Platform-specific Registers

The following tables list platform-specific register names for SPARC and Intel that can be used in expressions.

SPARC Register Information

The following register information is for SPARC systems.

Register	Description
$g0 through $g7	Global registers
$o0 through $o7	"out" registers
$l0 through $l7	"local" registers
$i0 through $i7	"in" registers
$fp	Frame pointer, equivalent to register $i6
$sp	Stack pointer, equivalent to register $o6
$y	Y register
$psr	Processor state register
$wim	Window invalid mask register
$tbr	Trap base register
$pc	Program counter
$npc	Next program counter
$f0 through $f31	FPU "f" registers
$fsr	FPU status register
$fq	FPU queue

The $f0f1 $f2f3 ... $f30f31 pairs of floating point registers are treated as having C "double" type (normally $fN registers are treated as C "float" type). These pairs can also be referred to as $d0 ... $d30.

The following additional registers are available on SPARC V9 and V8+ hardware:

---

$g0g1 through $g6g7
$o0o1 through $o6o7
$xfsr $tstate $gsr
$f32f33 $f34f35 through $f62f63 ($d32 ... $$d62)

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See the SPARC Architecture Reference Manual and the Sun-4 Assembly Language Reference Manual for more information on SPARC registers and addressing.

Intel Register Information

The following register information is for Intel systems.

Register	Description
$gs	Alternate data segment register
$fs	Alternate data segment register
$es	Alternate data segment register
$ds	Data segment register
$edi	Destination index register
$esi	Source index register
$ebp	Frame pointer
$esp	Stack pointer
$ebx	General register
$edx	General register
$ecx	General register
$eax	General register
$trapno	Exception vector number
$err	Error code for exception
$eip	Instruction pointer
$cs	Code segment register
$eflags	Flags
$es	Alternate data segment register
$uesp	User stack pointer
$ss	Stack segment register

Commonly used registers are also aliased to their machine independent names:

$sp	Stack pointer; equivalent of $uesp
$pc	Program counter; equivalent of $eip
$fp	Frame pointer; equivalent of $ebp

Registers for the 80386 lower halves (16 bits) are:

$ax	General register
$cx	General register
$dx	General register
$bx	General register
$si	Source index register
$di	Destination index register
$ip	Instruction pointer, lower 16 bits
$flags	Flags, lower 16 bits

The first four 80386 16-bit registers can be split into 8-bit parts:

$al	Lower (right) half of register	$ax
$ah	Higher (left) half of register	$ax
$cl	Lower (right) half of register	$cx
$ch	Higher (left) half of register	$cx
$dl	Lower (right) half of register	$dx
$dh	Higher (left) half of register	$dx
$bl	Lower (right) half of register	$bx
$bh	Higher (left) half of register	$bx

Registers for the 80387 are:

$fctrl	Control register
$fstat	Status register
$ftag	Tag register
$fip	Instruction pointer offset
$fcs	Code segment selector
$fopoff	Operand pointer offset
$fopsel	Operand pointer selector
$st0 through $st7	Data registers