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

[Scott Wood <scottwood@freescale.com>]

On Thu, 2014-01-23 at 12:34 +0100, Alexander Graf wrote:
> On 23.01.2014, at 01:08, Scott Wood <scottwood@freescale.com> 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 <agraf@suse.de>
> >> ---
> >> 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?

I was thinking we could avoid the speed.c code entirely, along with
anything else that touches such things.

-Scott