Re: [Qemu-devel] [Qemu-ppc] [PATCH 07/10] PPC: guts: Add emulation of a few more registers

[Alexander Graf]

On 23.01.2014, at 01:08, Scott Wood <address@hidden> wrote:

> On Mon, 2014-01-20 at 00:44 +0100, Alexander Graf wrote:
>> The GUTS device is used by system software to find out about hardware
>> details of the current system.
>> 
>> We only emulate the bare minimum to be able to reboot a guest which is
>> not sufficient to make u-boot happy.
>> 
>> Add a few more registers to our portfolio with dummy values.
>> 
>> Signed-off-by: Alexander Graf <address@hidden>
>> ---
>> hw/ppc/mpc8544_guts.c | 12 ++++++++++++
>> 1 file changed, 12 insertions(+)
>> 
>> diff --git a/hw/ppc/mpc8544_guts.c b/hw/ppc/mpc8544_guts.c
>> index a10abe9..af8c742 100644
>> --- a/hw/ppc/mpc8544_guts.c
>> +++ b/hw/ppc/mpc8544_guts.c
>> @@ -25,6 +25,8 @@
>> #define MPC8544_GUTS_RSTCR_RESET      0x02
>> 
>> #define MPC8544_GUTS_ADDR_PORPLLSR    0x00
>> +#define PORPLLSR_SYS_RATIO_MAX        0x3e
>> +#define PORPLLSR_CPU0_RATIO_MAX       (0x3f << 16)
>> #define MPC8544_GUTS_ADDR_PORBMSR     0x04
>> #define MPC8544_GUTS_ADDR_PORIMPSCR   0x08
>> #define MPC8544_GUTS_ADDR_PORDEVSR    0x0C
>> @@ -36,6 +38,7 @@
>> #define MPC8544_GUTS_ADDR_GPINDR      0x50
>> #define MPC8544_GUTS_ADDR_PMUXCR      0x60
>> #define MPC8544_GUTS_ADDR_DEVDISR     0x70
>> +#define DEVDISR_DISABLED_NONE         0x0
>> #define MPC8544_GUTS_ADDR_POWMGTCSR   0x80
>> #define MPC8544_GUTS_ADDR_MCPSUMR     0x90
>> #define MPC8544_GUTS_ADDR_RSTRSCR     0x94
>> @@ -73,6 +76,15 @@ static uint64_t mpc8544_guts_read(void *opaque, hwaddr 
>> addr,
>> 
>>     addr &= MPC8544_GUTS_MMIO_SIZE - 1;
>>     switch (addr) {
>> +    case MPC8544_GUTS_ADDR_PORPLLSR:
>> +        value = PORPLLSR_SYS_RATIO_MAX | PORPLLSR_CPU0_RATIO_MAX;
>> +        break;
>> +    case MPC8544_GUTS_ADDR_PORDEVSR:
>> +        value = 0;
>> +        break;
>> +    case MPC8544_GUTS_ADDR_DEVDISR:
>> +        value = DEVDISR_DISABLED_NONE;
>> +        break;
> 
> But we don't actually have most of these devices that you're claiming
> aren't disabled via DEVDISR -- and with the paravirt target, what do
> these registers even mean?

For PORDEVSR and DEVDISR I agree - I'll just remove the code in u-boot that 
accesses them. It's all in board code anyway.

For PORPLLSR things are more complicated. I'm not really a big fan of touching 
speed.c and adding complicated and hard to test preprocessor statements. So how 
about we leave that one in?

Alex

> 
> I'd rather see U-Boot not touch these registers for the QEMU target,
> rather than returning arbitrary values.
> 
> -Scott