Re: [Qemu-devel] [RFC v3 08/10] hw/m68k: add a dummy SWIM floppy controller

["Hervé Poussineau" <hpoussin@reactos.org>]

Le 28/06/2018 à 01:29, Laurent Vivier a écrit :
> Co-developed-by: Mark Cave-Ayland <mark.cave-ayland@ilande.co.uk>
> Signed-off-by: Mark Cave-Ayland <mark.cave-ayland@ilande.co.uk>
> Signed-off-by: Laurent Vivier <laurent@vivier.eu>
> ---
>   hw/block/Makefile.objs  |   1 +
>   hw/block/swim.c         | 284 ++++++++++++++++++++++++++++++++++++++++++++++++
>   include/hw/block/swim.h |  53 +++++++++
>   3 files changed, 338 insertions(+)
>   create mode 100644 hw/block/swim.c
>   create mode 100644 include/hw/block/swim.h
> 
> diff --git a/hw/block/Makefile.objs b/hw/block/Makefile.objs
> index 53ce5751ae..068de3f0c9 100644
> --- a/hw/block/Makefile.objs
> +++ b/hw/block/Makefile.objs
> @@ -8,6 +8,7 @@ common-obj-$(CONFIG_XEN) += xen_disk.o
>   common-obj-$(CONFIG_ECC) += ecc.o
>   common-obj-$(CONFIG_ONENAND) += onenand.o
>   common-obj-$(CONFIG_NVME_PCI) += nvme.o
> +common-obj-$(CONFIG_SWIM) += swim.o
>   
>   obj-$(CONFIG_SH4) += tc58128.o
>   
> diff --git a/hw/block/swim.c b/hw/block/swim.c
> new file mode 100644
> index 0000000000..6b1d0371e8
> --- /dev/null
> +++ b/hw/block/swim.c
> @@ -0,0 +1,284 @@
> +/*
> + * QEMU Macintosh floppy disk controller emulator (SWIM)
> + *
> + * Copyright (c) 2014-2018 Laurent Vivier <laurent@vivier.eu>
> + *
> + * This work is licensed under the terms of the GNU GPL, version 2.  See
> + * the COPYING file in the top-level directory.
> + *
> + */
> +
> +#include "qemu/osdep.h"
> +#include "hw/sysbus.h"
> +#include "hw/block/swim.h"
> +
> +/* IWM registers */
> +
> +#define IWM_PH0L                0
> +#define IWM_PH0H                1
> +#define IWM_PH1L                2
> +#define IWM_PH1H                3
> +#define IWM_PH2L                4
> +#define IWM_PH2H                5
> +#define IWM_PH3L                6
> +#define IWM_PH3H                7
> +#define IWM_MTROFF              8
> +#define IWM_MTRON               9
> +#define IWM_INTDRIVE            10
> +#define IWM_EXTDRIVE            11
> +#define IWM_Q6L                 12
> +#define IWM_Q6H                 13
> +#define IWM_Q7L                 14
> +#define IWM_Q7H                 15
> +
> +/* SWIM registers */
> +
> +#define SWIM_WRITE_DATA         0
> +#define SWIM_WRITE_MARK         1
> +#define SWIM_WRITE_CRC          2
> +#define SWIM_WRITE_PARAMETER    3
> +#define SWIM_WRITE_PHASE        4
> +#define SWIM_WRITE_SETUP        5
> +#define SWIM_WRITE_MODE0        6
> +#define SWIM_WRITE_MODE1        7
> +
> +#define SWIM_READ_DATA          8
> +#define SWIM_READ_MARK          9
> +#define SWIM_READ_ERROR         10
> +#define SWIM_READ_PARAMETER     11
> +#define SWIM_READ_PHASE         12
> +#define SWIM_READ_SETUP         13
> +#define SWIM_READ_STATUS        14
> +#define SWIM_READ_HANDSHAKE     15
> +
> +#define REG_SHIFT               9
> +
> +#define SWIM_MODE_IWM  0
> +#define SWIM_MODE_SWIM 1
> +
> +/* bits in phase register */
> +
> +#define SWIM_SEEK_NEGATIVE   0x074
> +#define SWIM_STEP            0x071
> +#define SWIM_MOTOR_ON        0x072
> +#define SWIM_MOTOR_OFF       0x076
> +#define SWIM_INDEX           0x073
> +#define SWIM_EJECT           0x077
> +#define SWIM_SETMFM          0x171
> +#define SWIM_SETGCR          0x175
> +#define SWIM_RELAX           0x033
> +#define SWIM_LSTRB           0x008
> +#define SWIM_CA_MASK         0x077
> +
> +/* Select values for swim_select and swim_readbit */
> +
> +#define SWIM_READ_DATA_0     0x074
> +#define SWIM_TWOMEG_DRIVE    0x075
> +#define SWIM_SINGLE_SIDED    0x076
> +#define SWIM_DRIVE_PRESENT   0x077
> +#define SWIM_DISK_IN         0x170
> +#define SWIM_WRITE_PROT      0x171
> +#define SWIM_TRACK_ZERO      0x172
> +#define SWIM_TACHO           0x173
> +#define SWIM_READ_DATA_1     0x174
> +#define SWIM_MFM_MODE        0x175
> +#define SWIM_SEEK_COMPLETE   0x176
> +#define SWIM_ONEMEG_MEDIA    0x177
> +
> +/* Bits in handshake register */
> +
> +#define SWIM_MARK_BYTE       0x01
> +#define SWIM_CRC_ZERO        0x02
> +#define SWIM_RDDATA          0x04
> +#define SWIM_SENSE           0x08
> +#define SWIM_MOTEN           0x10
> +#define SWIM_ERROR           0x20
> +#define SWIM_DAT2BYTE        0x40
> +#define SWIM_DAT1BYTE        0x80
> +
> +/* bits in setup register */
> +
> +#define SWIM_S_INV_WDATA     0x01
> +#define SWIM_S_3_5_SELECT    0x02
> +#define SWIM_S_GCR           0x04
> +#define SWIM_S_FCLK_DIV2     0x08
> +#define SWIM_S_ERROR_CORR    0x10
> +#define SWIM_S_IBM_DRIVE     0x20
> +#define SWIM_S_GCR_WRITE     0x40
> +#define SWIM_S_TIMEOUT       0x80
> +
> +/* bits in mode register */
> +
> +#define SWIM_CLFIFO          0x01
> +#define SWIM_ENBL1           0x02
> +#define SWIM_ENBL2           0x04
> +#define SWIM_ACTION          0x08
> +#define SWIM_WRITE_MODE      0x10
> +#define SWIM_HEDSEL          0x20
> +#define SWIM_MOTON           0x80
> +
> +
> +static void iwmctrl_write(void *opaque, hwaddr reg, uint64_t value,
> +                          unsigned size)
> +{
> +    SWIMCtrl *swimctrl = opaque;
> +
> +    reg >>= REG_SHIFT;
> +
> +    swimctrl->regs[reg >> 1] = reg & 1;
> +
> +    if (swimctrl->regs[IWM_Q6] &&
> +        swimctrl->regs[IWM_Q7]) {
> +        if (swimctrl->regs[IWM_MTR]) {
> +            /* data register */
> +            swimctrl->iwm_data = value;
> +        } else {
> +            /* mode register */
> +            swimctrl->iwm_mode = value;
> +            /* detect sequence to switch from IWM mode to SWIM mode */
> +            switch (swimctrl->iwm_switch) {
> +            case 0:
> +                if (value == 0x57) {
> +                    swimctrl->iwm_switch++;
> +                }
> +                break;
> +            case 1:
> +                if (value == 0x17) {
> +                    swimctrl->iwm_switch++;
> +                }
> +                break;
> +            case 2:
> +                if (value == 0x57) {
> +                    swimctrl->iwm_switch++;
> +                }
> +                break;
> +            case 3:
> +                if (value == 0x57) {
> +                    swimctrl->mode = SWIM_MODE_SWIM;
> +                    swimctrl->iwm_switch = 0;
> +                }
> +                break;
> +            }

I assume that the values of the sequence must be contiguous. If you don't follow it, you have to restart from scratch.
In that case, you're missing the "else { swimctrl->iwm_switch = 0; }" in the cases 1 to 3.

You may also use the following pattern:
     static const uint8_t iwm_switch_sequence[] = { 0x57, 0x17, 0x57, 0x57 };
     if (value == iwm_switch_sequence[swimctrl->iwm_switch]) {
         swimctrl->iwm_switch++;
         if (swimctrl->iwm_switch == ARRAY_SIZE(iwm_switch_sequence)) {
             swimctrl->mode = SWIM_MODE_SWIM;
             swimctrl->iwm_switch = 0;
         }
     } else {
         swimctrl->iwm_switch = 0;
     }


Hervé

> +        }
> +    }
> +}
> +
> +static uint64_t iwmctrl_read(void *opaque, hwaddr reg, unsigned size)
> +{
> +    SWIMCtrl *swimctrl = opaque;
> +
> +    reg >>= REG_SHIFT;
> +
> +    swimctrl->regs[reg >> 1] = reg & 1;
> +
> +    return 0;
> +}
> +
> +static void swimctrl_write(void *opaque, hwaddr reg, uint64_t value,
> +                           unsigned size)
> +{
> +    SWIMCtrl *swimctrl = opaque;
> +
> +    if (swimctrl->mode == SWIM_MODE_IWM) {
> +        iwmctrl_write(opaque, reg, value, size);
> +        return;
> +    }
> +
> +    reg >>= REG_SHIFT;
> +
> +    switch (reg) {
> +    case SWIM_WRITE_PHASE:
> +        swimctrl->swim_phase = value;
> +        break;
> +    case SWIM_WRITE_MODE0:
> +        swimctrl->swim_mode &= ~value;
> +        break;
> +    case SWIM_WRITE_MODE1:
> +        swimctrl->swim_mode |= value;
> +        break;
> +    case SWIM_WRITE_DATA:
> +    case SWIM_WRITE_MARK:
> +    case SWIM_WRITE_CRC:
> +    case SWIM_WRITE_PARAMETER:
> +    case SWIM_WRITE_SETUP:
> +        break;
> +    }
> +}
> +
> +static uint64_t swimctrl_read(void *opaque, hwaddr reg, unsigned size)
> +{
> +    SWIMCtrl *swimctrl = opaque;
> +    uint32_t value = 0;
> +
> +    if (swimctrl->mode == SWIM_MODE_IWM) {
> +        return iwmctrl_read(opaque, reg, size);
> +    }
> +
> +    reg >>= REG_SHIFT;
> +
> +    switch (reg) {
> +    case SWIM_READ_PHASE:
> +        value = swimctrl->swim_phase;
> +        break;
> +    case SWIM_READ_HANDSHAKE:
> +        if (swimctrl->swim_phase == SWIM_DRIVE_PRESENT) {
> +            /* always answer "no drive present" */
> +            value = SWIM_SENSE;
> +        }
> +        break;
> +    case SWIM_READ_DATA:
> +    case SWIM_READ_MARK:
> +    case SWIM_READ_ERROR:
> +    case SWIM_READ_PARAMETER:
> +    case SWIM_READ_SETUP:
> +    case SWIM_READ_STATUS:
> +        break;
> +    }
> +
> +    return value;
> +}
> +
> +static const MemoryRegionOps swimctrl_mem_ops = {
> +    .write = swimctrl_write,
> +    .read = swimctrl_read,
> +    .endianness = DEVICE_NATIVE_ENDIAN,
> +};
> +
> +static void swim_init(Object *obj)
> +{
> +    SysBusDevice *sbd = SYS_BUS_DEVICE(obj);
> +    SWIMCtrl *swimctrl = SWIM(obj);
> +
> +    memory_region_init_io(&swimctrl->iomem, obj, &swimctrl_mem_ops, swimctrl,
> +                          "swim", 0x2000);
> +    sysbus_init_mmio(sbd, &swimctrl->iomem);
> +}
> +
> +static Property swim_properties[] = {
> +    DEFINE_PROP_DRIVE("driveA", SWIMCtrl, drives[0].blk),
> +    DEFINE_PROP_DRIVE("driveB", SWIMCtrl, drives[1].blk),
> +    DEFINE_PROP_END_OF_LIST(),
> +};
> +
> +static void swim_class_init(ObjectClass *oc, void *data)
> +{
> +    DeviceClass *dc = DEVICE_CLASS(oc);
> +
> +    dc->props = swim_properties;
> +    set_bit(DEVICE_CATEGORY_STORAGE, dc->categories);
> +}
> +
> +static const TypeInfo swim_info = {
> +    .name          = TYPE_SWIM,
> +    .parent        = TYPE_SYS_BUS_DEVICE,
> +    .instance_size = sizeof(SWIMCtrl),
> +    .instance_init = swim_init,
> +    .class_init    = swim_class_init,
> +};
> +
> +static void swim_register_types(void)
> +{
> +    type_register_static(&swim_info);
> +}
> +
> +type_init(swim_register_types)
> diff --git a/include/hw/block/swim.h b/include/hw/block/swim.h
> new file mode 100644
> index 0000000000..2c0258967c
> --- /dev/null
> +++ b/include/hw/block/swim.h
> @@ -0,0 +1,53 @@
> +/*
> + * QEMU Macintosh floppy disk controller emulator (SWIM)
> + *
> + * Copyright (c) 2014-2018 Laurent Vivier <laurent@vivier.eu>
> + *
> + * This work is licensed under the terms of the GNU GPL, version 2.  See
> + * the COPYING file in the top-level directory.
> + *
> + */
> +
> +#ifndef SWIM_H
> +#define SWIM_H
> +
> +#include "qemu/osdep.h"
> +#include "hw/sysbus.h"
> +
> +#define MAX_FD                  2
> +
> +typedef struct SWIMCtrl SWIMCtrl;
> +
> +typedef struct FDrive {
> +    SWIMCtrl *swimctrl;
> +    BlockBackend *blk;
> +} FDrive;
> +
> +#define TYPE_SWIM "swim"
> +#define SWIM(obj) OBJECT_CHECK(SWIMCtrl, (obj), TYPE_SWIM)
> +
> +typedef struct SWIMCtrl {
> +    SysBusDevice parent_obj;
> +
> +    MemoryRegion iomem;
> +    FDrive drives[MAX_FD];
> +    int mode;
> +    /* IWM mode */
> +    int iwm_switch;
> +    int regs[8];
> +#define IWM_PH0   0
> +#define IWM_PH1   1
> +#define IWM_PH2   2
> +#define IWM_PH3   3
> +#define IWM_MTR   4
> +#define IWM_DRIVE 5
> +#define IWM_Q6    6
> +#define IWM_Q7    7
> +    uint8_t iwm_data;
> +    uint8_t iwm_mode;
> +    /* SWIM mode */
> +    uint8_t swim_phase;
> +    uint8_t swim_mode;
> +} SWIMCtrl;
> +
> +#endif
>