Re: [Qemu-devel] [V6, 2/7] nios2: Add architecture emulation support

[Marek Vasut]

On 11/13/2016 01:01 PM, Marek Vasut wrote:
> On 11/13/2016 12:25 AM, Guenter Roeck wrote:
>> Hi Marek,
> 
> Hi!
> 
>> On 11/12/2016 01:50 PM, Marek Vasut wrote:
>>> On 11/07/2016 08:54 PM, Guenter Roeck wrote:
>>>> Hi Marek,
>>>>
>>>> On 11/07/2016 10:14 AM, Marek Vasut wrote:
>>>>> On 11/07/2016 04:58 AM, Guenter Roeck wrote:
>>>>>> On Tue, Oct 25, 2016 at 09:57:43PM +0200, Marek Vasut wrote:
>>>>>>> From: Chris Wulff <address@hidden>
>>>>>>>
>>>>>>> Add support for emulating Altera NiosII R1 architecture into qemu.
>>>>>>> This patch is based on previous work by Chris Wulff from 2012 and
>>>>>>> updated to latest mainline QEMU.
>>>>>>>
>>>>>>> Signed-off-by: Marek Vasut <address@hidden>
>>>>>>> Cc: Chris Wulff <address@hidden>
>>>>>>> Cc: Jeff Da Silva <address@hidden>
>>>>>>> Cc: Ley Foon Tan <address@hidden>
>>>>>>> Cc: Sandra Loosemore <address@hidden>
>>>>>>> Cc: Yves Vandervennet <address@hidden>
>>>>>>> ---
>>>>>>> V3: Thorough cleanup, deal with the review comments all over the
>>>>>>> place
>>>>>>> V4: - Use extract32()
>>>>>>>     - Fix gen_goto_tb() , suppress tcg_gen_goto_tb()
>>>>>>>     - Clean up gen_check_supervisor() helper
>>>>>>>     - Use TCGMemOp type for flags
>>>>>>>     - Drop jump labels from wrctl/rdctl
>>>>>>>     - More TCG cleanup
>>>>>>> V5: - Simplify load/store handling
>>>>>>>     - Handle loads into R_ZERO from protected page, add comment
>>>>>>> V6: - Fix division opcode handling
>>>>>>>     - Add missing disas handling
>>>>>>>     - V5 review comments cleanup
>>>>>>> ---
>>>>>> [ ... ]
>>>>>>
>>>>>>> diff --git a/target-nios2/cpu.h b/target-nios2/cpu.h
>>>>>>> new file mode 100644
>>>>>>> index 0000000..17c9a0f
>>>>>> [ ... ]
>>>>>>
>>>>>>> +static inline void cpu_get_tb_cpu_state(CPUNios2State *env,
>>>>>>> target_ulong *pc,
>>>>>>> +                                        target_ulong *cs_base,
>>>>>>> uint32_t *flags)
>>>>>>> +{
>>>>>>> +    *pc = env->regs[R_PC];
>>>>>>> +    *cs_base = 0;
>>>>>>> +    *flags = (env->regs[CR_STATUS] & (CR_STATUS_EH | CR_STATUS_U));
>>>>>>> +}
>>>>>>> +
>>>>>>> +#endif /* CPU_NIOS2_H */
>>>>>>> +
>>>>>>
>>>>>> The empty line at the end results in a whitespace message from git.
>>>>>
>>>>> Dropped, thanks. Is there anything else or is this patchset starting to
>>>>> become acceptable ?
>>>>>
>>>>
>>>> Hard for me to say. I tried to build and run the series with the latest
>>>> linux
>>>> kernel (v4.9-rc4), but it is stuck in early boot. I tried with
>>>> 10m50_defconfig
>>>> and 10m50_devboard.dtb. gcc is 6.1.0 built with buildroot, though I also
>>>> tried
>>>> with toolchains from CodeSourcery. Obviously I have no idea if there
>>>> is a
>>>> kernel bug or a qemu bug or a problem with the command line I used.
>>>>
>>>> Here is my command line:
>>>>
>>>> qemu-system-nios2 -M 10m50-ghrd -kernel vmlinux -dtb
>>>> 10m50_devboard.dtb \
>>>>     -append "earlycon=uart8250,mmio32,0x18001600,115200n8 console=ttyS0"
>>>>
>>>> This may be wrong, but the boot is stuck in an endless loop in
>>>> mark_bootmem(),
>>>> which seems early and odd. I tried with both vmlinux and
>>>> arch/nios2/boot/vmImage,
>>>> with the same results.
>>>>
>>>> Can you provide a working command line and kernel version, and/or
>>>> directions how
>>>> to create a working image if I need to run the image, for example, from
>>>> u-boot ?
>>>> Sorry if that is posted somewhere and I missed it.
>>>
>>> I guess Romain gave you something since I see you made some progress.
>>> I'll have to look into that fdt loader issue.
>>>
>>
>> Yes, WFM after
>>
>> diff --git a/hw/nios2/boot.c b/hw/nios2/boot.c
>> index 564dbae..e0a9aff 100644
>> --- a/hw/nios2/boot.c
>> +++ b/hw/nios2/boot.c
>> @@ -73,6 +73,11 @@ static void main_cpu_reset(void *opaque)
>>      }
>>  }
>>
>> +static uint64_t translate_kernel_address(void *opaque, uint64_t addr)
>> +{
>> +    return addr - 0xc0000000LL;
>> +}
>> +
>>  static int nios2_load_dtb(struct nios2_boot_info bi, const uint32_t
>> ramsize,
>>                            const char *kernel_cmdline, const char
>> *dtb_filename)
>>  {
>> @@ -97,21 +102,16 @@ static int nios2_load_dtb(struct nios2_boot_info
>> bi, const uint32_t ramsize,
>>
>>      if (bi.initrd_start) {
>>          qemu_fdt_setprop_cell(fdt, "/chosen", "linux,initrd-start",
>> -                              bi.initrd_start);
>> +                              translate_kernel_address(NULL,
>> bi.initrd_start));
>>
>>          qemu_fdt_setprop_cell(fdt, "/chosen", "linux,initrd-end",
>> -                              bi.initrd_end);
>> +                              translate_kernel_address(NULL,
>> bi.initrd_end));
>>      }
>>
>>      cpu_physical_memory_write(bi.fdt, fdt, fdt_size);
>>      return fdt_size;
>>  }
>>
>> -static uint64_t translate_kernel_address(void *opaque, uint64_t addr)
>> -{
>> -    return addr - 0xc0000000LL;
>> -}
>> -
>>  void nios2_load_kernel(Nios2CPU *cpu, hwaddr ddr_base,
>>
>>
>> This is my command line, running your patch series plus the above fixup
>> on top of
>> the qemu master branch:
> 
> Uhm, how could that patch fix the DT passing for you ? I am still
> looking into the DT passing, that's quite odd.
> 
This patch makes the DT passing work for me, but I cannot put my finger
on why. It moves the DT a bit further in memory, that's all.

diff --git a/hw/nios2/boot.c b/hw/nios2/boot.c
index 564dbae..c9e3e69 100644
--- a/hw/nios2/boot.c
+++ b/hw/nios2/boot.c
@@ -178,7 +183,7 @@ void nios2_load_kernel(Nios2CPU *cpu, hwaddr ddr_base,
             high = ddr_base + kernel_size;
         }

-        high = ROUND_UP(high, 1024 * 1024);
+        high = ROUND_UP(high, 1024 * 1024) + 0x10000;

         /* If initrd is available, it goes after the kernel, aligned to
1M. */
         if (initrd_filename) {


-- 
Best regards,
Marek Vasut