Configuring the Example Driver

Configuring the Example Driver

Before you configure the example driver into the kernel, you should set the system with a debugging kernel, as described under "Preparing the System for Debugging".

Configure the example driver to IRIX by copying files as follows:

Copy the ramdrive.o file to /var/sysgen/boot.
Edit the ramdrive descriptive file and make any necessary changes. For example:
- The file specifies major device number 77. If there is another driver in the system using this major number, change 77 to any unused number in the range 60-79 (see "Major Device Number").
- The fourth option, #DEV, is set to 4. This controls how many unique minor devices the driver supports.
Copy the edited ramdrive descriptive file to /var/sysgen/master.d.
Edit the ramdrive.sm file and make any desired changes. For example,
- Change a base= value to change the size of a RAM drive
- Add or remove VECTOR lines to change the number of minor devices that are initialized.
Copy the edited ramdrive.sm file to /var/sysgen/system.
Reboot the system.

If you compiled the example driver with -DDEBUG, it displays several informational lines to the system console from its rd_init(), rd_start(), and rd_edtinit() entry points. The display from rd_edtinit() gives the address of the rd_info_t structure. You can display that area with idbg. Example 12-2 shows the result of displaying a simulated volume header structure, using an address displayed from rd_edtinit() (the actual address will differ).

Example 12-2 : Displaying Simulated Volume Header Using idbg

# idbg hd 0x8841f604 0x80
0x8841f604: 0b e5 a9 41  00 00 00 01  00 00 00 00  00 00 00 00 ...A............
0x8841f614: 00 00 00 00  00 00 00 00  00 00 00 00  02 00 00 00 ................
0x8841f624: 00 01 00 00  00 00 00 08  02 00 00 01  00 00 00 00 ................
0x8841f634: 00 00 00 00  00 00 00 00  00 00 00 00  00 00 00 00 ................
0x8841f644: 00 00 00 00  00 00 00 00  00 00 00 00  00 00 00 00 ................
0x8841f654: 00 00 00 00  00 00 00 00  00 00 00 00  00 00 00 00 ................
0x8841f664: 00 00 00 00  00 00 00 00  00 00 00 00  00 00 00 00 ................
0x8841f674: 00 00 00 00  00 00 00 00  00 00 00 00  00 00 00 00 ................
0x8841f684: 00 00 00 00  00 00 00 00  00 00 00 00  00 00 00 00 ................
0x8841f694: 00 00 00 00  00 00 00 00  00 00 00 00  00 00 00 00 ................
0x8841f6a4: 00 00 00 00  00 00 00 00  00 00 00 00  00 00 00 00 ................
0x8841f6b4: 00 00 00 00  00 00 00 00  00 00 00 00  00 00 00 00 ................
0x8841f6c4: 00 00 00 00  00 00 00 00  00 00 00 00  00 00 00 00 ................
0x8841f6d4: 00 00 00 00  00 00 00 00  00 00 00 00  00 00 00 00 ................
0x8841f6e4: 00 00 00 00  00 00 00 00  00 00 00 00  00 00 00 00 ................
0x8841f6f4: 00 00 00 00  00 00 00 00  00 00 00 00  00 00 00 00 ................
0x8841f704: 00 00 00 00  00 00 00 00  00 00 00 00  00 00 00 00 ................
0x8841f714: 00 00 00 00  00 00 00 00  00 00 00 00  00 00 00 00 ................
0x8841f724: 00 00 00 00  00 00 00 00  00 00 00 00  00 00 00 00 ................
0x8841f734: 00 00 00 00  00 00 00 00  00 00 0f ff  00 00 00 01 ................
0x8841f744: 00 00 00 03  00 00 00 00  00 00 10 00  00 00 00 03 ................
0x8841f754: 00 00 00 00  00 00 00 00  00 00 00 00  00 00 00 00 ................
0x8841f764: 00 00 00 00  00 00 00 00  00 00 00 00  00 00 00 00 ................
0x8841f774: 00 00 00 00  00 00 00 00  00 00 00 00  00 00 00 00 ................
0x8841f784: 00 00 00 00  00 00 00 00  00 00 00 00  00 00 0f ff ................
0x8841f794: 00 00 00 01  00 00 00 03  00 00 00 01  00 00 00 00 ................
0x8841f7a4: 00 00 00 00  00 00 00 00  00 00 00 00  00 00 00 00 ................
0x8841f7b4: 00 00 10 00  00 00 00 00  00 00 00 06  00 00 00 00 ................
0x8841f7c4: 00 00 00 00  00 00 00 00  00 00 00 00  00 00 00 00 ................
0x8841f7d4: 00 00 00 00  00 00 00 00  00 00 00 00  00 00 00 00 ................
0x8841f7e4: 00 00 00 00  00 00 00 00  00 00 00 00  00 00 00 00 ................
0x8841f7f4: 00 00 00 00  00 00 00 00  f0 19 16 a5  00 00 00 00 ................