Re: [Qemu-devel] [PULL v2 8/8] hw/mips: MIPS Boston board support

[Yongbok Kim]

On 23/02/2017 18:09, Peter Maydell wrote:
> On 22 February 2017 at 00:21, Yongbok Kim <address@hidden> wrote:
>> From: Paul Burton <address@hidden>
>>
>> Introduce support for emulating the MIPS Boston development board. The
>> Boston board is built around an FPGA & 3 PCIe controllers, one of which
>> is connected to an Intel EG20T Platform Controller Hub. It is used
>> during the development & debug of new CPUs and the software intended to
>> run on them, and is essentially the successor to the older MIPS Malta
>> board.
>>
>> This patch does not implement the EG20T, instead connecting an already
>> supported ICH-9 AHCI controller. Whilst this isn't accurate it's enough
>> for typical stock Boston software (eg. Linux kernels) to work with hard
>> disks given that both the ICH-9 & EG20T implement the AHCI
>> specification.
>>
>> Boston boards typically boot kernels in the FIT image format, and this
>> patch will treat kernels provided to QEMU as such. When loading a kernel
>> directly, the board code will generate minimal firmware much as the
>> Malta board code does. This firmware will set up the CM, CPC & GIC
>> register base addresses then set argument registers & jump to the kernel
>> entry point. Alternatively, bootloader code may be loaded using the bios
>> argument in which case no firmware will be generated & execution will
>> proceed from the start of the boot code at the default MIPS boot
>> exception vector (offset 0x1fc00000 into (c)kseg1).
>>
>> Currently real Boston boards are always used with FPGA bitfiles that
>> include a Global Interrupt Controller (GIC), so the interrupt
>> configuration is only defined for such cases. Therefore the board will
>> only allow use of CPUs which implement the CPS components, including the
>> GIC, and will otherwise exit with a message.
>>
>> +static void boston_mach_class_init(MachineClass *mc)
>> +{
>> +    mc->desc = "MIPS Boston";
>> +    mc->init = boston_mach_init;
>> +    mc->block_default_type = IF_IDE;
>> +    mc->default_ram_size = 2 * G_BYTE;
>> +    mc->max_cpus = 16;
>> +}
> 
> I only just noticed, but this breaks "make check" on 32-bit hosts:
> 
> TEST: tests/qom-test... (pid=16740)
>   /mips64el/qom/boston:
> qemu-system-mips64el: at most 2047 MB RAM can be simulated
> Broken pipe
> FAIL
> 
> because vl.c has
>         /* On 32-bit hosts, QEMU is limited by virtual address space */
>         if (ram_size > (2047 << 20) && HOST_LONG_BITS == 32) {
>             error_report("at most 2047 MB RAM can be simulated");
>             exit(1);
>         }
> 
> Unfortunately I didn't notice before I pushed your pull request.
> Luckily this is the last patch in the pullreq, so I can just
> revert this one commit (d3473e147a754e999718bf6fcb015d9978c6a1ee)...
> 
> Please fix the board model patch and resend it. You'll need
> the board to default to a ram size that works on all hosts.
> 
> (I'm taking the revert option because we're getting pretty
> close to freeze and I have a bunch of pull requests in the
> queue that I'd prefer not to delay while we fix this up.)
> 
> thanks
> -- PMM
> 

My apologies for the inconvenience! I missed to check it on the 32-bit hosts.

I am not seeing the revert commit on the master?
I've sent a modified patch with the fix and a pull request containing
reverting the commit by myself and the updated Boston patch.

Regards,
Yongbok