2017-06-11 23:39 GMT+03:00 Hesham Almatary <heshamelmat...@gmail.com>:
> On Mon, Jun 12, 2017 at 6:01 AM, Denis Obrezkov <denisobrez...@gmail.com> > wrote: > > 2017-06-11 22:43 GMT+03:00 Hesham Almatary <heshamelmat...@gmail.com>: > >> > >> Hi Denis, > >> > >> > >> > >> On Sun, Jun 11, 2017 at 11:52 PM, Denis Obrezkov > >> <denisobrez...@gmail.com> wrote: > >> > Hello Hesham, > >> > > >> > I found out that your code in interrupt handling routine is outdated - > >> Which interrupt handling routine? The port doesn't handle interrupts. > >> The only relevant code is enable/disable interrupts, but it doesn't > >> matter at this stage that it's outdated (as we don't have interrupts). > >> > >> > the format of mstatus and sstatus registers was changed. > >> > I can produce some patches in a few days, though, I still don't > >> > understand > >> > how to deal with local and global interrupts. > >> > > >> Could you illustrate what do you mean by "global" and "local" > >> interrupts? I still argue for a simple port that runs hello world, you > >> don't need interrupts, so this shouldn't be a blocker for you. > >> > >> > -- > >> > Regards, Denis Obrezkov > >> > >> > >> > >> -- > >> Hesham > > > > RISC-V has local and global interrupt sources: Privileged ISA 1.10, > chapter > > 7.2. > > > Thanks for the reference. After reading this part, global interrupts > are mapped to external interrupts that are not part of RISC-V ISA. > While local interrupts are per-hart and defined/controlled by RISC-V > ISA using mstatus/mip/sip registers. For example, if you're going to > implement interrupts-based UART driver (platform/BSP specific), you'll > need global/external interrupts hence PLIC. On the other hand, when > you implement timer driver, you'll use local interrupts (RISC-V/ISA > specific). > > > > > > > -- > > Regards, Denis Obrezkov > > > > -- > Hesham > Yes, thanks, I found the answer for my question - when a PLIC interrupt occurs, it raises a global interrupt, which has the exception code of eleven (E31-Coreplex Manual, 6.2). Thus, we should place our global interrupts' handler with the offset of 0x2c. -- Regards, Denis Obrezkov
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