Re: Point where target instructions are read

[Gautam Bhat <mindentropy@gmail.com>]

Ah I had my .tlb_fill callback set to an empty function with just
returning true. I need to put the actual code there. Let me fill this
function up and see what happens.

-Gautam.

On Thu, Apr 11, 2024 at 2:45 AM Gautam Bhat <mindentropy@gmail.com> wrote:
>
> On Tue, Apr 9, 2024 at 2:23 PM Peter Maydell <peter.maydell@linaro.org> wrote:
>
> > That sounds like a problem with your binary. If the reset vector
> > needs to be at 0xFFFE then it needs to be there, and you
> > should arrange for it to be built correctly. It doesn't matter
> > whether it's an ELF file or a raw binary file, the data has
> > to be in the right place. (Generally when objcopy creates a raw
> > binary from an ELF file it doesn't change the address where
> > the data is, assuming you load the resulting raw binary to the
> > right starting address.)
> >
> > -- PMM
>
> It was a problem with me loading it to the right address. Went through
> the manual again and I found that the ROM address starts at 0xC000.
> Hence I was supposed to load at that address. Loading at that address
> places the reset vector interrupt in the right location. Now I get the
> right program counter value which is 0xC000 which is the code in the
> ROM.
>
> I went ahead to check if I now get the right opcode but I am still
> getting zeroes. Digging through the code when I do the following for
> translate:
>
> static void translate(DisasContext *ctx)
> {
>     uint32_t opcode;
>
>     opcode = cpu_lduw_code(ctx->msp430_cpu_state,
>                     ctx->base.pc_next);
>     qemu_fprintf(stderr, "Opcode: 0x%x\n", opcode);
> }
>
>
> cpu_lduw_code calls mmu_index callback. In my callback I have
>
> static int msp430_cpu_mmu_index(CPUState *cp, bool ifetch)
> {
>     return MMU_CODE_DATA_IDX;
> }
>
> Here I have just set the MMU_CODE_DATA_IDX to 1 which I know does not
> make sense. I am not sure how this index is supposed to be computed.
> Any idea on what to look at to understand it?
>
> -Gautam.