fix: lapic address is higher than 0xC0000000 (not 0x7000) El mié., 22 abr. 2020 a las 19:15, Almudena Garcia (< liberamenso10...@gmail.com>) escribió:
> After this talk, I agree with Damien about the cpu enumeration (reading > from ACPI tables), must be implemented in gnumach. > But my question is, how can I avoid the dirty addressing currently in use? > > Currently, the APIC table is read before configure paging, to avoid paging > restrictions when I access to this memory space. > But this cause another problem: the lapic is mapped in a very high address > (upper to 0x7000), and is unreachable in this moment. > In my solution, I take notes about the lapic address and wait until paging > is enabled to map this address. But this is a dirty solution, in my opinion. > > My code is here: > https://github.com/AlmuHS/GNUMach_SMP/blob/smp/i386/i386at/acpi_rsdp.c > > Are there any other solution for this? > > Furthermore, I create many global variables that, talking with Richard, he > told me that is a bad practice. > How can I solve this problem? > > Thanks > > El mié., 22 abr. 2020 a las 10:03, Samuel Thibault (< > samuel.thiba...@gnu.org>) escribió: > >> Damien Zammit, le mer. 22 avril 2020 15:57:26 +1000, a ecrit: >> > >> I have a feeling we are going to need all of acpica incorporated >> into gnumach eventually, >> > >> because you need a full ACPI parser for learning the PCI interrupts >> and proper shutdown mechanism. >> > > >> > > Can't the parsing be done in userland (like we do for shutdown), and >> > > just hand over the information to the kernel? >> > >> > Shutdown mechanism can be done this way, yes - there is plenty of time >> to parse the tables in userspace before shutdown. >> > >> > However, I believe interrupt configuration of the IOAPIC(s) and >> activation of the other cores >> > needs to be done very early, even before the first disk interrupt >> occurs. >> >> I was thinking that perhaps the system can boot with just one core and >> enable the other cores after bootstrap. We don't really need smp support >> very early in the boot. >> >> > It seems much more appropriate and easier to read the in-memory ACPI >> tables at a fixed memory address (eg. ESCD 0xe0000) >> > in gnumach and bootstrap the system from an SMP enabled kernel so the >> kernel already knows >> > how to drive interrupts and timers before any other servers launch. >> >> If parsing the ACPI tables just for SMP is simple enough, yes, that >> should be fine and make the whole picture simpler. >> >> > Are you suggesting to create an interrupt/timer server? >> >> No, that seems too extreme to me. >> >> Samuel >> >>
