Re: [Qemu-devel] [PATCH v2 1/2] hw/arm/virt: Provide flash devices for boot ROMs

[Peter Crosthwaite]

On Wed, Jun 11, 2014 at 3:06 AM, Peter Maydell <address@hidden> wrote:
> Add two flash devices to the virt board, so that it can be used for
> running guests which want a bootrom image such as UEFI. We provide
> two flash devices to make it more convenient to provide both a
> read-only UEFI image and a read-write place to store guest-set
> UEFI config variables. The '-bios' command line option is set up
> to provide an image for the first of the two flash devices.
>
> Signed-off-by: Peter Maydell <address@hidden>
> ---
>  hw/arm/virt.c | 71 
> ++++++++++++++++++++++++++++++++++++++++++++++++++++++++++-
>  1 file changed, 70 insertions(+), 1 deletion(-)
>
> diff --git a/hw/arm/virt.c b/hw/arm/virt.c
> index 3b55a4b..e658eb0 100644
> --- a/hw/arm/virt.c
> +++ b/hw/arm/virt.c
> @@ -37,6 +37,7 @@
>  #include "sysemu/sysemu.h"
>  #include "sysemu/kvm.h"
>  #include "hw/boards.h"
> +#include "hw/loader.h"
>  #include "exec/address-spaces.h"
>  #include "qemu/bitops.h"
>  #include "qemu/error-report.h"
> @@ -94,7 +95,6 @@ typedef struct VirtBoardInfo {
>   * a 32 bit VM and leaving space for expansion and in particular for PCI.
>   */
>  static const MemMapEntry a15memmap[] = {
> -    /* Space up to 0x8000000 is reserved for a boot ROM */
>      [VIRT_FLASH] = { 0, 0x8000000 },
>      [VIRT_CPUPERIPHS] = { 0x8000000, 0x20000 },
>      /* GIC distributor and CPU interfaces sit inside the CPU peripheral 
> space */
> @@ -375,6 +375,73 @@ static void create_virtio_devices(const VirtBoardInfo 
> *vbi, qemu_irq *pic)
>      }
>  }
>
> +static void create_one_flash(const char *name, hwaddr flashbase,
> +                             hwaddr flashsize)
> +{
> +    /* Create and map a single flash device. We use the same
> +     * parameters as the flash devices on the Versatile Express board.
> +     */
> +    DriveInfo *dinfo = drive_get_next(IF_PFLASH);
> +    DeviceState *dev = qdev_create(NULL, "cfi.pflash01");
> +    const uint64_t sectorlength = 256 * 1024;
> +
> +    if (dinfo && qdev_prop_set_drive(dev, "drive", dinfo->bdrv)) {
> +        abort();
> +    }
> +
> +    qdev_prop_set_uint32(dev, "num-blocks", flashsize / sectorlength);
> +    qdev_prop_set_uint64(dev, "sector-length", sectorlength);
> +    qdev_prop_set_uint8(dev, "width", 4);
> +    qdev_prop_set_uint8(dev, "device-width", 2);
> +    qdev_prop_set_uint8(dev, "big-endian", 0);
> +    qdev_prop_set_uint16(dev, "id0", 0x89);
> +    qdev_prop_set_uint16(dev, "id1", 0x18);
> +    qdev_prop_set_uint16(dev, "id2", 0x00);
> +    qdev_prop_set_uint16(dev, "id3", 0x00);
> +    qdev_prop_set_string(dev, "name", name);
> +    qdev_init_nofail(dev);
> +
> +    sysbus_mmio_map(SYS_BUS_DEVICE(dev), 0, flashbase);
> +}
> +
> +static void create_flash(const VirtBoardInfo *vbi)
> +{
> +    /* Create two flash devices to fill the VIRT_FLASH space in the memmap.
> +     * Any file passed via -bios goes in the first of these.
> +     */
> +    hwaddr flashsize = vbi->memmap[VIRT_FLASH].size / 2;
> +    hwaddr flashbase = vbi->memmap[VIRT_FLASH].base;
> +    char *nodename;
> +
> +    if (bios_name) {
> +        const char *fn;
> +
> +        if (drive_get(IF_PFLASH, 0, 0)) {

Does the bios actually have to be in pflash? Does the guest expect
pflash controllability or will any memory-mapped read-only device do?
I'm thinking this can be simplified by having the -bios arg back onto
a raw read-only MemoryRegion (inited here) and then the one-and-only
-pflash arg is usable consistently for your read-and-write area
(second half).

Regards,
Peter

> +            error_report("The contents of the first flash device may be "
> +                         "specified with -bios or with -drive if=pflash... "
> +                         "but you cannot use both options at once");
> +            exit(1);
> +        }
> +        fn = qemu_find_file(QEMU_FILE_TYPE_BIOS, bios_name);
> +        if (!fn || load_image_targphys(fn, flashbase, flashsize) < 0) {
> +            error_report("Could not load ROM image '%s'", bios_name);
> +            exit(1);
> +        }
> +    }
> +
> +    create_one_flash("virt.flash0", flashbase, flashsize);
> +    create_one_flash("virt.flash1", flashbase + flashsize, flashsize);
> +
> +    nodename = g_strdup_printf("/address@hidden" PRIx64, flashbase);
> +    qemu_fdt_add_subnode(vbi->fdt, nodename);
> +    qemu_fdt_setprop_string(vbi->fdt, nodename, "compatible", "cfi-flash");
> +    qemu_fdt_setprop_sized_cells(vbi->fdt, nodename, "reg",
> +                                 2, flashbase, 2, flashsize,
> +                                 2, flashbase + flashsize, 2, flashsize);
> +    qemu_fdt_setprop_cell(vbi->fdt, nodename, "bank-width", 4);
> +    g_free(nodename);
> +}
> +
>  static void *machvirt_dtb(const struct arm_boot_info *binfo, int *fdt_size)
>  {
>      const VirtBoardInfo *board = (const VirtBoardInfo *)binfo;
> @@ -451,6 +518,8 @@ static void machvirt_init(MachineState *machine)
>      vmstate_register_ram_global(ram);
>      memory_region_add_subregion(sysmem, vbi->memmap[VIRT_MEM].base, ram);
>
> +    create_flash(vbi);
> +
>      create_gic(vbi, pic);
>
>      create_uart(vbi, pic);
> --
> 1.9.2
>
>