Author: Dale Roberts, Direct I/O and Windows NT
Here are two helpful hints to get you going with GIVEIO. The first
section below mentions the INSTDRV utility that is provided with the
Microsoft DDK. If you do not have access to the DDK, you can use Paula
Tomlinson's program LOADDRV instead. She describes it in her May 1995
article in Windows/DOS Developer's Journal (now Windows Developer's
Journal). You can get the program from their FTP site at:
ftp://ftp.mfi.com/pub/windev/1995/may95.zip.
------------------------------------------------------------------
Device Driver Installation Made Easy
The Microsoft NT Device Driver Kit documentation implies in several
places that there are several steps involved in installing a device driver
and making it accessible to a Win32 application. It explains that you
should edit the registry manually and then reboot the system. But
device drivers are dynamically loadable and unloadable in NT, and the
DDK comes with a very handy utility called INSTDRV that
demonstrates this facility in a very practical manner.
INSTDRV is a console application that will register, load, and start a
kernel mode device driver. It does not require you to edit the registry
manually or reboot the computer. On the command line you simply
give the name of your device driver and the complete path to the .SYS
file (which does not need to be in the system's DRIVERS directory).
After this command is executed, you will find that the driver has been
registered with the system and appears in the Devices applet in the
control panel. If you give the word remove instead of the path, the
driver is removed from the system and taken out of the driver database.
Once the driver is loaded and started, you can use the control panel's
Devices applet to start and stop it, or you can use the net start and net
stop commands (these are much faster) from a console window. When
a kernel mode device is stopped, it is in also unloaded from memory.
The next time you start the device, a fresh copy of the driver is read
from the hard drive, if it has been modified. This makes it very
convenient to develop device drivers, since you can go through the
modify, stop, start cycle repeatedly without ever needing to reboot. If
you need your driver to load at boot time, you can go into the Devices
applet and change its startup mode to boot.
The other component that is needed to make the driver visible to user
mode applications, so they can use CreateFile() calls to access the
driver, is registering the name in the DOS Devices name space. This
can be done, as documented in the DDK, by editing the registry
manually and rebooting. Or, much more simply, the kernel mode
driver can call the IoCreateSymbolicLink() function to register the
name itself. The GIVEIO driver shown in Listing Four uses the later
technique. Once the name is registered, user mode applications can get
a file handle to the device driver by calling CreateFile() with the driver
name as the file parameter, but preceding the driver name with the
special cookie \\.\. The TESTIO application in Listing Five uses this
technique.
------------------------------------------------------------------
Quick Trick: Using DEBUG With Port I/O
Sometimes you just need to do a quick I/O operation to a port. In DOS,
you could use the DEBUG program to accomplish this. In NT, once
you have the GIVEIO device driver up and running, you can once
again use DEBUG for port I/O. If you look at the source code for the
test application, you'll see that all it does is open and close the GIVEIO
device driver. It uses the special cookie \\.\ before the driver name in
order to access it. Without modifying DEBUG, you can have it open
this device driver by simply typing debug \\.\giveio in an NT console
window. You will get an error message complaining that the file
\\.\giveio is not found, but it will give DEBUG I/O access anyway.
Subsequent DOS applications that are run from this console window
will also have I/O access.
WIN32 applications executed from this console window will still cause
exceptions. This is because DEBUG (and any other DOS application)
runs in the context of the VDM (Virtual DOS Machine) process of the
console box, whereas each WIN32 application gets its own process.
The VDM process stays active as long as the console window is open,
but each WIN32 application creates a brand new process with the
IOPM offset initialized to point beyond the end of the TSS.
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亚嵌培训项目源代码部分 (950个子文件)
__image.axf 44KB
my1.axf 44KB
my2.axf 44KB
my3.axf 44KB
bootloader.axf 31KB
test8.axf 31KB
test8.axf 30KB
bootloader.axf 29KB
helloworld.axf 29KB
helloword.axf 29KB
main.axf 26KB
bootloader.axf 26KB
bootloader.axf 22KB
bootloader.axf 17KB
ADS_demo_und.axf 17KB
ADS_demo_swi.axf 16KB
ADS_demo_led_int0_beep_dip.axf 16KB
ADS_demo_int0.axf 14KB
zonghe.axf 13KB
ADS_demo_int0.axf 13KB
bootloader.axf 13KB
ADS_demo_swi_s.axf 13KB
ADS_demo_dip4_seg7.axf 11KB
ADS_demo_uart_timer.axf 11KB
key.axf 11KB
handle_interrupts.axf 9KB
bootloader.axf 9KB
global.axf 9KB
handle_interrupts.axf 9KB
led.axf 8KB
ADS_demo_dip4.axf 8KB
handle_interrupts.axf 8KB
ADS_demo_uart.axf 8KB
ADS_demo_seg7.axf 8KB
handle_interrupts.axf 8KB
ADS_demo_beep.axf 8KB
handle_interrupts.axf 8KB
ADS_demo_led.axf 8KB
ADS_demo_led.axf 8KB
ADS_demo_dip4.axf 8KB
ADS_demo_timer.axf 7KB
und.axf 7KB
handle_interrupt.axf 7KB
timer_interrupt.axf 7KB
swi.axf 7KB
handle_interrupt.axf 7KB
main.axf 7KB
enable_interrupt.axf 6KB
enable_interrupt.axf 6KB
bootloader.axf 6KB
main.axf 6KB
test8.axf 4KB
seg7.axf 3KB
test4.axf 2KB
test7.axf 2KB
led.axf 1KB
led.axf 1KB
led.axf 1KB
test2.axf 1KB
test2.axf 1KB
test5.axf 1KB
test3.axf 1KB
test1.axf 1KB
test6.axf 1KB
init.s.bak 4KB
snds.s.bak 4KB
flash_39vf160.c.bak 3KB
main.c.bak 3KB
main.c.bak 3KB
shell.c.bak 3KB
irq.c.bak 2KB
main.c.bak 2KB
main.c.bak 2KB
led.c.bak 2KB
main.c.bak 2KB
shell.c.bak 2KB
main.c.bak 2KB
main.c.bak 2KB
und.bin.bak 2KB
main.c.bak 2KB
startup.s.bak 2KB
startup.s.bak 2KB
irq.c.bak 2KB
printf.c.bak 2KB
timer.c.bak 2KB
irq.c.bak 1KB
main.c.bak 1KB
main.c.bak 1KB
int0.c.bak 1KB
main.c.bak 1KB
main.c.bak 1KB
timer.c.bak 1KB
beep.c.bak 1KB
beep.c.bak 1KB
startup.s.bak 959B
stdio.c.bak 889B
Makefile.bak 764B
testfile3.s.bak 735B
main.c.bak 678B
main.c.bak 664B
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资源评论
- sunris2012-06-30亚嵌的培训还是不错的,适合入门
- 潇湘夜雨222012-11-27很专业,很有针对性
- beyondjjw2012-06-17亚嵌的培训还是不错的,适合入门
shyboytao
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