I have a question about the Real-time Clock component (RTC) for the x86 VMM
found here:
https://github.com/SEL4PROJ/global-components/blob/master/components/RTC/RTC...
Here is the text of the camkes file:
import ;
import ;
component CMOS {
hardware;
provides IOPort cmos_address;
provides IOPort cmos_data;
attribute string cmos_address_attributes = "0x70:0x70";
attribute string cmos_data_attributes = "0x71:0x71";
}
component RTC {
provides RTC rtc;
maybe uses PutChar putchar;
uses IOPort cmos_address;
uses IOPort cmos_data;
attribute int heap_size = 0;
/* Connect the hardware RTC to the RTC component */
composition {
component CMOS cmos;
connection seL4HardwareIOPort rtc_cmos_address(from cmos_address,
to cmos.cmos_address);
connection seL4HardwareIOPort rtc_cmos_data(from cmos_data, to
cmos.cmos_data);
}
configuration {
cmos.cmos_address_attributes <- cmos_address_attributes;
cmos.cmos_data_attributes <- cmos_data_attributes;
}
}
What is the meaning of the last two statements in the configuration block?
what is the scoping rules for the "cmos_address_attributes" and
"cmos_data_attributes" variables? It looks like these attributes are
already set in the definition of the CMOS component? They seemed to be
assigned again in the configuration block?
- John
