debug(HW)

Description

The following commands are available:

?

show help

b address

set breakpoint at address

B

list breakpoints

c address

clear breakpoint at address

C

clear all

g address

continue execution at address or current instruction pointer cs:ip if an address is not given

p address

print 16 bytes of data at address in hexadecimal and ASCII; successive 16-byte chunks are displayed each time you press <Enter>

P address

print 8 words of data at address in hexadecimal and ASCII; successive 8-word chunks are displayed each time you press <Enter>

r

display registers

R register value

set register to value

s

single step the next instruction

S

print the stack

w address value

write byte value to an address

W address value

write word value to an address

All addresses take the form segment:offset, where each component is a 16-bit hexadecimal quantity. Register names can be substituted for either segment or offset; the current value of the register is then used in its place. For example, the instruction pointer may be specified by cs:ip, and the stack pointer by ss:sp. All numeric values are input and displayed in hexadecimal.

The debugger is compiled into boot and makes use of both the standalone library and the system BIOS. Do not set breakpoints within the BIOS or within the printf( ) or gets( ) functions of the standalone library.

It is possible to format hard disks if the BIOS has a low level format routine. Run the debugger and use the segment and offset values documented in your hardware guide, for example:

   g C800:6

See also

For more information about kernel debugging, see the Consolidated Hardware Development (HDK) Web Page