Re: [Qemu-devel] [PULL 050/107] prep: add IBM RS/6000 7020 (40p) machine emulation

[Hervé Poussineau]

Le 12/02/2017 à 22:15, Artyom Tarasenko a écrit :
> On Thu, Feb 2, 2017 at 6:13 AM, David Gibson
> <address@hidden> wrote:
> > From: Hervé Poussineau <address@hidden>
> >
> > Machine supports both Open Hack'Ware and OpenBIOS.
> > Open Hack'Ware is the default because OpenBIOS is currently unable to boot
> > PReP boot partitions or PReP kernels.
> >
> > Signed-off-by: Hervé Poussineau <address@hidden>
> > [dwg: Correct compile failure with KVM located by Thomas Huth]
> > Signed-off-by: David Gibson <address@hidden>
> > ---
> >  default-configs/ppc-softmmu.mak |   1 +
> >  hw/ppc/prep.c                   | 230 ++++++++++++++++++++++++++++++++++++++++
> >  2 files changed, 231 insertions(+)
> >
> > diff --git a/default-configs/ppc-softmmu.mak b/default-configs/ppc-softmmu.mak
> > index e567658..7dd004e 100644
> > --- a/default-configs/ppc-softmmu.mak
> > +++ b/default-configs/ppc-softmmu.mak
> > @@ -18,6 +18,7 @@ CONFIG_I82378=y
> >  CONFIG_PC87312=y
> >  CONFIG_MACIO=y
> >  CONFIG_PCSPK=y
> > +CONFIG_CS4231A=y
> >  CONFIG_CUDA=y
> >  CONFIG_ADB=y
> >  CONFIG_MAC_NVRAM=y
> > diff --git a/hw/ppc/prep.c b/hw/ppc/prep.c
> > index 9fb89d3..ca7959c 100644
> > --- a/hw/ppc/prep.c
> > +++ b/hw/ppc/prep.c
> > @@ -2,6 +2,7 @@
> >   * QEMU PPC PREP hardware System Emulator
> >   *
> >   * Copyright (c) 2003-2007 Jocelyn Mayer
> > + * Copyright (c) 2017 Hervé Poussineau
> >   *
> >   * Permission is hereby granted, free of charge, to any person obtaining a copy
> >   * of this software and associated documentation files (the "Software"), to 
> > deal
> > @@ -43,17 +44,21 @@
> >  #include "hw/isa/pc87312.h"
> >  #include "sysemu/block-backend.h"
> >  #include "sysemu/arch_init.h"
> > +#include "sysemu/kvm.h"
> >  #include "sysemu/qtest.h"
> >  #include "exec/address-spaces.h"
> >  #include "trace.h"
> >  #include "elf.h"
> >  #include "qemu/cutils.h"
> > +#include "kvm_ppc.h"
> >
> >  /* SMP is not enabled, for now */
> >  #define MAX_CPUS 1
> >
> >  #define MAX_IDE_BUS 2
> >
> > +#define CFG_ADDR 0xf0000510
> > +
> >  #define BIOS_SIZE (1024 * 1024)
> >  #define BIOS_FILENAME "ppc_rom.bin"
> >  #define KERNEL_LOAD_ADDR 0x01000000
> > @@ -316,6 +321,12 @@ static uint32_t PREP_io_800_readb (void *opaque, uint32_t 
> > addr)
> >
> >  #define NVRAM_SIZE        0x2000
> >
> > +static void fw_cfg_boot_set(void *opaque, const char *boot_device,
> > +                            Error **errp)
> > +{
> > +    fw_cfg_modify_i16(opaque, FW_CFG_BOOT_DEVICE, boot_device[0]);
> > +}
> > +
> >  static void ppc_prep_reset(void *opaque)
> >  {
> >      PowerPCCPU *cpu = opaque;
> > @@ -677,4 +688,223 @@ static void prep_machine_init(MachineClass *mc)
> >      mc->default_boot_order = "cad";
> >  }
> >
> > +static int prep_set_cmos_checksum(DeviceState *dev, void *opaque)
> > +{
> > +    uint16_t checksum = *(uint16_t *)opaque;
> > +    ISADevice *rtc;
> > +
> > +    if (object_dynamic_cast(OBJECT(dev), "mc146818rtc")) {
> > +        rtc = ISA_DEVICE(dev);
> > +        rtc_set_memory(rtc, 0x2e, checksum & 0xff);
> > +        rtc_set_memory(rtc, 0x3e, checksum & 0xff);
> > +        rtc_set_memory(rtc, 0x2f, checksum >> 8);
> > +        rtc_set_memory(rtc, 0x3f, checksum >> 8);
> > +    }
> > +    return 0;
> > +}
> > +
> > +static void ibm_40p_init(MachineState *machine)
> > +{
> > +    CPUPPCState *env = NULL;
> > +    uint16_t cmos_checksum;
> > +    PowerPCCPU *cpu;
> > +    DeviceState *dev;
> > +    SysBusDevice *pcihost;
> > +    Nvram *m48t59 = NULL;
> > +    PCIBus *pci_bus;
> > +    ISABus *isa_bus;
> > +    void *fw_cfg;
> > +    int i;
> > +    uint32_t kernel_base = 0, initrd_base = 0;
> > +    long kernel_size = 0, initrd_size = 0;
> > +    char boot_device;
> > +
> > +    /* init CPU */
> > +    if (!machine->cpu_model) {
> > +        machine->cpu_model = "604";
> > +    }
> > +    cpu = cpu_ppc_init(machine->cpu_model);
> > +    if (!cpu) {
> > +        error_report("could not initialize CPU '%s'",
> > +                     machine->cpu_model);
> > +        exit(1);
> > +    }
> > +    env = &cpu->env;
> > +    if (PPC_INPUT(env) != PPC_FLAGS_INPUT_6xx) {
> > +        error_report("only 6xx bus is supported on this machine");
> > +        exit(1);
> > +    }
> > +
> > +    if (env->flags & POWERPC_FLAG_RTC_CLK) {
> > +        /* POWER / PowerPC 601 RTC clock frequency is 7.8125 MHz */
> > +        cpu_ppc_tb_init(env, 7812500UL);
>
> Is this necessary? Looks like it sets both decrementer and cpu
> frequency to 7.8125 MHz,
> so the machine with -cpu 601 is working very slow.

It is a copy/paste from 'prep' machine.
This code has been added 10 years ago, and commit said:
"  New PowerPC CPU flag to define the decrementer and time-base source clock.
   Use it to properly initialize the clock for the PreP target."

If you think that it is incorrect, feel free to send a patch.

> > +    } else {
> > +        /* Set time-base frequency to 100 Mhz */
> > +        cpu_ppc_tb_init(env, 100UL * 1000UL * 1000UL);
> > +    }
> > +    qemu_register_reset(ppc_prep_reset, cpu);

[...]

Hervé