System information

6 Hardware Monitor Functionality
Figure 6.8: Actual content of the screen. Figure 6.9: Previous content of the screen.
Figure 6.10: Menu bar of the BIOS setup utility of an AMI BIOS.
This information is used to validate and to control automated host interaction of the
CHARM like the setup of the BIOS settings. Running an alphanumeric video mode, the
detection of highlighted text content is very simple. The second video plane contains the
attribute byte of the corresponding character inside the first video plane (see section 4.1.2).
On the basis of the attribute byte, highlighted text can be detected. The following para-
graph shows a dump of the device file /dev/charm/vga/text which provides the characters
and the corresponding attribute bytes of the current screen content. In this process, the
output represents the screen content of the running BIOS setup utility shown in figure 6.10.
Thereby, the even addresses contain the characters and the odd the related attribute byte.
The characters are print out in their ASCII representation, whereas the attribute byte are
shown as octal values.
charm-b03:/ $ hexdump /dev/charm/vga/text -c
0000000 037 037 037 037 037 037 037 037
*
0000030 037 037 037 037 037 037 037 B 037
0000040 I 037 O 037 S 037 037 S 037 E 037 T 037 U 037
0000050 P 037 037 U 037 T 037 I 037 L 037 I 037 T 037
0000060 Y 037 037 037 037 037 037 037 037
0000070 037 037 037 037 037 037 037 037
*
00000a0 027 027 027 M 161 a 161 i 161 n 161 027
00000b0 027 027 027 A 027 d 027 v 027 a 027 n 027
00000c0 c 027 e 027 d 027 027 027 027 027 C 027
00000d0 h 027 i 027 p 027 s 027 e 027 t 027 027 027
88