The developer will need to acquire a DSDT data file from any machine
with ACPI BIOS through
acpidump(8).
The DSDT is a table, a part of the whole ACPI memory table
located in somewhere in the BIOS area
(0xa0000
-
0x100000
).
It includes such information as the detailed hardware information
for PnP, and the set of procedures which perform power management from
the OS.
The information is stored in AML format.
The AML interpreter can execute any of the Control Methods specified by users. When executed, it interprets the byte sequence in the Control Method of DSDT, and disassembles the opcodes that it recognizes into ASL (ACPI Source Language) format to be displayed.
If it encounters one of more accesses to the region such as SystemMemory in executing the Control Methods, its ACPI Virtual Machine simulates the input/output operations to the resources in the region. In writing to a certain region, the ACPI Virtual Machine prepares a piece of memory corresponding to its address, if necessary, and holds the specified value in the memory as the region contents. In reading from a certain region, it fetches the value in the memory (region contents), prompts with it as the following:
DEBUG[read(0, 0x100b6813)&mask:0x1](default: 0x1 / 1) >>
for users to have the opportunity to modify it, and hands it to the AML interpreter. In case that there is no corresponding region in the AML Virtual Machine, the value zero is handed.
The interpreter continues to maintain all of the
region contents
until
amldb
terminates.
You can specify their initial values with the file
region.ini
in the current directory.
If it is executed with
-d
option, it dumps the final status of all of its
region contents
to the file
region.dmp
when it terminates.
Each line of there files consists of the following
fields, separated by tabs; region type, address, and value.
Region types are specified as follows;
Interactive commands are described below:
Method: Arg 1 From 0x280626ce To 0x28062775
Enter argument values (ex. number 1 / string foo). 'q' to quit.
Arg0 ?
For each argument, a pair of type string and value delimited by
one or more spaces can be entered.
Now only
number
and
string
can be specified as the type string.
In the current implementation, only the first character of the type
string, such as
n
or
s,
is identified.
For example, we can enter as follows:
Arg0 ? n 1
region.dmp
.
region.ini
region.dmp
_PRS
(Possible Resource Settings)
objects, and executing the
_PTS
(Prepare To Sleep)
Control Method by the AML interpreter.
% amldb p2b.dsdt.dat
Loading p2b.dsdt.dat...done
AML>f _PRS
\_SB_.PCI0.ISA_.PS2M._PRS.
\_SB_.PCI0.ISA_.IRDA._PRS.
\_SB_.PCI0.ISA_.UAR2._PRS.
\_SB_.PCI0.ISA_.UAR1._PRS.
\_SB_.PCI0.ISA_.ECP_._PRS.
\_SB_.PCI0.ISA_.LPT_._PRS.
\_SB_.PCI0.ISA_.FDC0._PRS.
\_SB_.LNKD._PRS.
\_SB_.LNKC._PRS.
\_SB_.LNKB._PRS.
\_SB_.LNKA._PRS.
AML>r _PTS
Method: Arg 1 From 0x2805f0a3 To 0x2805f0db
Enter argument values (ex. number 1 / string foo). 'q' to quit.
Arg0 ? n 5
==== Running _PTS. ====
AML>s
[\_PTS. START]
If(LNot(LEqual(Arg0, 0x5)))
AML>
If(LEqual(Arg0, 0x1))
AML>
If(LEqual(Arg0, 0x2))
AML>
Store(One, TO12)
[aml_region_write(1, 1, 0x1, 0xe42c, 0x18, 0x1)]
amldb: region.ini: No such file or directory
[1:0x00@0xe42f]->[1:0x01@0xe42f]
[write(1, 0x1, 0xe42f)]
[aml_region_read(1, 1, 0xe42c, 0x18, 0x1)]
[1:0x01@0xe42f]
DEBUG[read(1, 0xe42f)&mask:0x1](default: 0x1 / 1) >>
[read(1, 0xe42f)->0x1]
AML>
Or(Arg0, 0xf0, Local2)[Copy number 0xf5]
AML>t
_PTS Method: Arg 1 From 0x2805f0a3 To 0x2805f0db
Arg0 Num:0x5
Local2 Num:0xf5
AML>s
Store(Local2, DBG1)
[aml_region_write(1, 1, 0xf5, 0x80, 0x0, 0x8)]
[1:0x00@0x80]->[1:0xf5@0x80]
[write(1, 0xf5, 0x80)]
[aml_region_read(1, 1, 0x80, 0x0, 0x8)]
[1:0xf5@0x80]
DEBUG[read(1, 0x80)&mask:0xf5](default: 0xf5 / 245) >>
[read(1, 0x80)->0xf5]
AML>
[\_PTS. END]
_PTS Method: Arg 1 From 0x2805f0a3 To 0x2805f0db
NO object
==== _PTS finished. ====
AML>q
%
Some contributions made by
Chitoshi Ohsawa <ohsawa@catv1.ccn-net.ne.jp>
,
Takayasu IWANASHI <takayasu@wendy.a.perfect-liberty.or.jp>
,
Norihiro KUMAGAI <kumagai@home.com>
,
Kenneth Ingham <ingham@I-pi.com>
,
and
Michael Lucas <mwlucas@blackhelicopters.org>
.
Because the AML interpreter interprets and disassembles simultaneously, it is impossible to implement such features as setting breakpoints with the specified line number in ASL. Setting breakpoints at certain Control Methods, which is not very difficult, has not yet implemented because nobody has ever needed it.