m25p80: Initial implementation of SPI flash device

Added device model for m25p80 style SPI flash family.

Signed-off-by: Peter A. G. Crosthwaite <peter.crosthwaite@petalogix.com>

5 files changed, 604 insertions, 0 deletions

diff --git a/default-configs/arm-softmmu.mak b/default-configs/arm-softmmu.mak
index f335a725f0..2f1a5c9943 100644
--- a/default-configs/arm-softmmu.mak
+++ b/default-configs/arm-softmmu.mak
@@ -22,6 +22,7 @@ CONFIG_ADS7846=y
 CONFIG_MAX111X=y
 CONFIG_SSI=y
 CONFIG_SSI_SD=y
+CONFIG_SSI_M25P80=y
 CONFIG_LAN9118=y
 CONFIG_SMC91C111=y
 CONFIG_DS1338=y
diff --git a/default-configs/microblaze-softmmu.mak b/default-configs/microblaze-softmmu.mak
index 64c9485de4..2f442e5aea 100644
--- a/default-configs/microblaze-softmmu.mak
+++ b/default-configs/microblaze-softmmu.mak
@@ -5,3 +5,5 @@ CONFIG_PFLASH_CFI01=y
 CONFIG_SERIAL=y
 CONFIG_XILINX=y
 CONFIG_XILINX_AXI=y
+CONFIG_SSI=y
+CONFIG_SSI_M25P80=y
diff --git a/default-configs/microblazeel-softmmu.mak b/default-configs/microblazeel-softmmu.mak
index a9622760c9..af9a3cde0d 100644
--- a/default-configs/microblazeel-softmmu.mak
+++ b/default-configs/microblazeel-softmmu.mak
@@ -5,3 +5,5 @@ CONFIG_PFLASH_CFI01=y
 CONFIG_SERIAL=y
 CONFIG_XILINX=y
 CONFIG_XILINX_AXI=y
+CONFIG_SSI=y
+CONFIG_SSI_M25P80=y
diff --git a/hw/Makefile.objs b/hw/Makefile.objs
index 66abbb2c7e..854faa9b5b 100644
--- a/hw/Makefile.objs
+++ b/hw/Makefile.objs
@@ -174,6 +174,7 @@ common-obj-y += scsi-disk.o cdrom.o hd-geometry.o block-common.o
 common-obj-y += scsi-generic.o scsi-bus.o
 common-obj-y += hid.o
 common-obj-$(CONFIG_SSI) += ssi.o
+common-obj-$(CONFIG_SSI_M25P80) += m25p80.o
 common-obj-$(CONFIG_SSI_SD) += ssi-sd.o
 common-obj-$(CONFIG_SD) += sd.o
 common-obj-y += bt.o bt-l2cap.o bt-sdp.o bt-hci.o bt-hid.o
diff --git a/hw/m25p80.c b/hw/m25p80.c
new file mode 100644
index 0000000000..9a56de8023
--- /dev/null
+++ b/hw/m25p80.c
@@ -0,0 +1,598 @@
+/*
+ * ST M25P80 emulator. Emulate all SPI flash devices based on the m25p80 command
+ * set. Known devices table current as of Jun/2012 and taken from linux.
+ * See drivers/mtd/devices/m25p80.c.
+ *
+ * Copyright (C) 2011 Edgar E. Iglesias <edgar.iglesias@gmail.com>
+ * Copyright (C) 2012 Peter A. G. Crosthwaite <peter.crosthwaite@petalogix.com>
+ * Copyright (C) 2012 PetaLogix
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public License as
+ * published by the Free Software Foundation; either version 2 or
+ * (at your option) a later version of the License.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License along
+ * with this program; if not, see <http://www.gnu.org/licenses/>.
+ */
+
+#include "hw.h"
+#include "blockdev.h"
+#include "ssi.h"
+#include "devices.h"
+
+#ifdef M25P80_ERR_DEBUG
+#define DB_PRINT(...) do { \
+    fprintf(stderr,  ": %s: ", __func__); \
+    fprintf(stderr, ## __VA_ARGS__); \
+    } while (0);
+#else
+    #define DB_PRINT(...)
+#endif
+
+/* Fields for FlashPartInfo->flags */
+
+/* erase capabilities */
+#define ER_4K 1
+#define ER_32K 2
+/* set to allow the page program command to write 0s back to 1. Useful for
+ * modelling EEPROM with SPI flash command set
+ */
+#define WR_1 0x100
+
+typedef struct FlashPartInfo {
+    const char *part_name;
+    /* jedec code. (jedec >> 16) & 0xff is the 1st byte, >> 8 the 2nd etc */
+    uint32_t jedec;
+    /* extended jedec code */
+    uint16_t ext_jedec;
+    /* there is confusion between manufacturers as to what a sector is. In this
+     * device model, a "sector" is the size that is erased by the ERASE_SECTOR
+     * command (opcode 0xd8).
+     */
+    uint32_t sector_size;
+    uint32_t n_sectors;
+    uint32_t page_size;
+    uint8_t flags;
+} FlashPartInfo;
+
+/* adapted from linux */
+
+#define INFO(_part_name, _jedec, _ext_jedec, _sector_size, _n_sectors, _flags)\
+    .part_name = (_part_name),\
+    .jedec = (_jedec),\
+    .ext_jedec = (_ext_jedec),\
+    .sector_size = (_sector_size),\
+    .n_sectors = (_n_sectors),\
+    .page_size = 256,\
+    .flags = (_flags),\
+
+static const FlashPartInfo known_devices[] = {
+    /* Atmel -- some are (confusingly) marketed as "DataFlash" */
+    { INFO("at25fs010",   0x1f6601,      0,  32 << 10,   4, ER_4K) },
+    { INFO("at25fs040",   0x1f6604,      0,  64 << 10,   8, ER_4K) },
+
+    { INFO("at25df041a",  0x1f4401,      0,  64 << 10,   8, ER_4K) },
+    { INFO("at25df321a",  0x1f4701,      0,  64 << 10,  64, ER_4K) },
+    { INFO("at25df641",   0x1f4800,      0,  64 << 10, 128, ER_4K) },
+
+    { INFO("at26f004",    0x1f0400,      0,  64 << 10,   8, ER_4K) },
+    { INFO("at26df081a",  0x1f4501,      0,  64 << 10,  16, ER_4K) },
+    { INFO("at26df161a",  0x1f4601,      0,  64 << 10,  32, ER_4K) },
+    { INFO("at26df321",   0x1f4700,      0,  64 << 10,  64, ER_4K) },
+
+    /* EON -- en25xxx */
+    { INFO("en25f32",     0x1c3116,      0,  64 << 10,  64, ER_4K) },
+    { INFO("en25p32",     0x1c2016,      0,  64 << 10,  64, 0) },
+    { INFO("en25q32b",    0x1c3016,      0,  64 << 10,  64, 0) },
+    { INFO("en25p64",     0x1c2017,      0,  64 << 10, 128, 0) },
+
+    /* Intel/Numonyx -- xxxs33b */
+    { INFO("160s33b",     0x898911,      0,  64 << 10,  32, 0) },
+    { INFO("320s33b",     0x898912,      0,  64 << 10,  64, 0) },
+    { INFO("640s33b",     0x898913,      0,  64 << 10, 128, 0) },
+
+    /* Macronix */
+    { INFO("mx25l4005a",  0xc22013,      0,  64 << 10,   8, ER_4K) },
+    { INFO("mx25l8005",   0xc22014,      0,  64 << 10,  16, 0) },
+    { INFO("mx25l1606e",  0xc22015,      0,  64 << 10,  32, ER_4K) },
+    { INFO("mx25l3205d",  0xc22016,      0,  64 << 10,  64, 0) },
+    { INFO("mx25l6405d",  0xc22017,      0,  64 << 10, 128, 0) },
+    { INFO("mx25l12805d", 0xc22018,      0,  64 << 10, 256, 0) },
+    { INFO("mx25l12855e", 0xc22618,      0,  64 << 10, 256, 0) },
+    { INFO("mx25l25635e", 0xc22019,      0,  64 << 10, 512, 0) },
+    { INFO("mx25l25655e", 0xc22619,      0,  64 << 10, 512, 0) },
+
+    /* Spansion -- single (large) sector size only, at least
+     * for the chips listed here (without boot sectors).
+     */
+    { INFO("s25sl004a",   0x010212,      0,  64 << 10,   8, 0) },
+    { INFO("s25sl008a",   0x010213,      0,  64 << 10,  16, 0) },
+    { INFO("s25sl016a",   0x010214,      0,  64 << 10,  32, 0) },
+    { INFO("s25sl032a",   0x010215,      0,  64 << 10,  64, 0) },
+    { INFO("s25sl032p",   0x010215, 0x4d00,  64 << 10,  64, ER_4K) },
+    { INFO("s25sl064a",   0x010216,      0,  64 << 10, 128, 0) },
+    { INFO("s25fl256s0",  0x010219, 0x4d00, 256 << 10, 128, 0) },
+    { INFO("s25fl256s1",  0x010219, 0x4d01,  64 << 10, 512, 0) },
+    { INFO("s25fl512s",   0x010220, 0x4d00, 256 << 10, 256, 0) },
+    { INFO("s70fl01gs",   0x010221, 0x4d00, 256 << 10, 256, 0) },
+    { INFO("s25sl12800",  0x012018, 0x0300, 256 << 10,  64, 0) },
+    { INFO("s25sl12801",  0x012018, 0x0301,  64 << 10, 256, 0) },
+    { INFO("s25fl129p0",  0x012018, 0x4d00, 256 << 10,  64, 0) },
+    { INFO("s25fl129p1",  0x012018, 0x4d01,  64 << 10, 256, 0) },
+    { INFO("s25fl016k",   0xef4015,      0,  64 << 10,  32, ER_4K | ER_32K) },
+    { INFO("s25fl064k",   0xef4017,      0,  64 << 10, 128, ER_4K | ER_32K) },
+
+    /* SST -- large erase sizes are "overlays", "sectors" are 4<< 10 */
+    { INFO("sst25vf040b", 0xbf258d,      0,  64 << 10,   8, ER_4K) },
+    { INFO("sst25vf080b", 0xbf258e,      0,  64 << 10,  16, ER_4K) },
+    { INFO("sst25vf016b", 0xbf2541,      0,  64 << 10,  32, ER_4K) },
+    { INFO("sst25vf032b", 0xbf254a,      0,  64 << 10,  64, ER_4K) },
+    { INFO("sst25wf512",  0xbf2501,      0,  64 << 10,   1, ER_4K) },
+    { INFO("sst25wf010",  0xbf2502,      0,  64 << 10,   2, ER_4K) },
+    { INFO("sst25wf020",  0xbf2503,      0,  64 << 10,   4, ER_4K) },
+    { INFO("sst25wf040",  0xbf2504,      0,  64 << 10,   8, ER_4K) },
+
+    /* ST Microelectronics -- newer production may have feature updates */
+    { INFO("m25p05",      0x202010,      0,  32 << 10,   2, 0) },
+    { INFO("m25p10",      0x202011,      0,  32 << 10,   4, 0) },
+    { INFO("m25p20",      0x202012,      0,  64 << 10,   4, 0) },
+    { INFO("m25p40",      0x202013,      0,  64 << 10,   8, 0) },
+    { INFO("m25p80",      0x202014,      0,  64 << 10,  16, 0) },
+    { INFO("m25p16",      0x202015,      0,  64 << 10,  32, 0) },
+    { INFO("m25p32",      0x202016,      0,  64 << 10,  64, 0) },
+    { INFO("m25p64",      0x202017,      0,  64 << 10, 128, 0) },
+    { INFO("m25p128",     0x202018,      0, 256 << 10,  64, 0) },
+
+    { INFO("m45pe10",     0x204011,      0,  64 << 10,   2, 0) },
+    { INFO("m45pe80",     0x204014,      0,  64 << 10,  16, 0) },
+    { INFO("m45pe16",     0x204015,      0,  64 << 10,  32, 0) },
+
+    { INFO("m25pe80",     0x208014,      0,  64 << 10,  16, 0) },
+    { INFO("m25pe16",     0x208015,      0,  64 << 10,  32, ER_4K) },
+
+    { INFO("m25px32",     0x207116,      0,  64 << 10,  64, ER_4K) },
+    { INFO("m25px32-s0",  0x207316,      0,  64 << 10,  64, ER_4K) },
+    { INFO("m25px32-s1",  0x206316,      0,  64 << 10,  64, ER_4K) },
+    { INFO("m25px64",     0x207117,      0,  64 << 10, 128, 0) },
+
+    /* Winbond -- w25x "blocks" are 64k, "sectors" are 4KiB */
+    { INFO("w25x10",      0xef3011,      0,  64 << 10,   2, ER_4K) },
+    { INFO("w25x20",      0xef3012,      0,  64 << 10,   4, ER_4K) },
+    { INFO("w25x40",      0xef3013,      0,  64 << 10,   8, ER_4K) },
+    { INFO("w25x80",      0xef3014,      0,  64 << 10,  16, ER_4K) },
+    { INFO("w25x16",      0xef3015,      0,  64 << 10,  32, ER_4K) },
+    { INFO("w25x32",      0xef3016,      0,  64 << 10,  64, ER_4K) },
+    { INFO("w25q32",      0xef4016,      0,  64 << 10,  64, ER_4K) },
+    { INFO("w25x64",      0xef3017,      0,  64 << 10, 128, ER_4K) },
+    { INFO("w25q64",      0xef4017,      0,  64 << 10, 128, ER_4K) },
+
+    /* Numonyx -- n25q128 */
+    { INFO("n25q128",      0x20ba18,      0,  64 << 10, 256, 0) },
+
+    { },
+};
+
+typedef enum {
+    NOP = 0,
+    PP = 0x2,
+    READ = 0x3,
+    WRDI = 0x4,
+    RDSR = 0x5,
+    WREN = 0x6,
+    FAST_READ = 0xb,
+    ERASE_4K = 0x20,
+    ERASE_32K = 0x52,
+    ERASE_SECTOR = 0xd8,
+    JEDEC_READ = 0x9f,
+    BULK_ERASE = 0xc7,
+} FlashCMD;
+
+typedef enum {
+    STATE_IDLE,
+    STATE_PAGE_PROGRAM,
+    STATE_READ,
+    STATE_COLLECTING_DATA,
+    STATE_READING_DATA,
+} CMDState;
+
+typedef struct Flash {
+    SSISlave ssidev;
+    uint32_t r;
+
+    BlockDriverState *bdrv;
+
+    uint8_t *storage;
+    uint32_t size;
+    int page_size;
+
+    uint8_t state;
+    uint8_t data[16];
+    uint32_t len;
+    uint32_t pos;
+    uint8_t needed_bytes;
+    uint8_t cmd_in_progress;
+    uint64_t cur_addr;
+    bool write_enable;
+
+    int64_t dirty_page;
+
+    char *part_name;
+    const FlashPartInfo *pi;
+
+} Flash;
+
+static void bdrv_sync_complete(void *opaque, int ret)
+{
+    /* do nothing. Masters do not directly interact with the backing store,
+     * only the working copy so no mutexing required.
+     */
+}
+
+static void flash_sync_page(Flash *s, int page)
+{
+    if (s->bdrv) {
+        int bdrv_sector, nb_sectors;
+        QEMUIOVector iov;
+
+        bdrv_sector = (page * s->pi->page_size) / BDRV_SECTOR_SIZE;
+        nb_sectors = DIV_ROUND_UP(s->pi->page_size, BDRV_SECTOR_SIZE);
+        qemu_iovec_init(&iov, 1);
+        qemu_iovec_add(&iov, s->storage + bdrv_sector * BDRV_SECTOR_SIZE,
+                                                nb_sectors * BDRV_SECTOR_SIZE);
+        bdrv_aio_writev(s->bdrv, bdrv_sector, &iov, nb_sectors,
+                                                bdrv_sync_complete, NULL);
+    }
+}
+
+static inline void flash_sync_area(Flash *s, int64_t off, int64_t len)
+{
+    int64_t start, end, nb_sectors;
+    QEMUIOVector iov;
+
+    if (!s->bdrv) {
+        return;
+    }
+
+    assert(!(len % BDRV_SECTOR_SIZE));
+    start = off / BDRV_SECTOR_SIZE;
+    end = (off + len) / BDRV_SECTOR_SIZE;
+    nb_sectors = end - start;
+    qemu_iovec_init(&iov, 1);
+    qemu_iovec_add(&iov, s->storage + (start * BDRV_SECTOR_SIZE),
+                                        nb_sectors * BDRV_SECTOR_SIZE);
+    bdrv_aio_writev(s->bdrv, start, &iov, nb_sectors, bdrv_sync_complete, NULL);
+}
+
+static void flash_erase(Flash *s, int offset, FlashCMD cmd)
+{
+    uint32_t len;
+    uint8_t capa_to_assert = 0;
+
+    switch (cmd) {
+    case ERASE_4K:
+        len = 4 << 10;
+        capa_to_assert = ER_4K;
+        break;
+    case ERASE_32K:
+        len = 32 << 10;
+        capa_to_assert = ER_32K;
+        break;
+    case ERASE_SECTOR:
+        len = s->pi->sector_size;
+        break;
+    case BULK_ERASE:
+        len = s->size;
+        break;
+    default:
+        abort();
+    }
+
+    DB_PRINT("offset = %#x, len = %d\n", offset, len);
+    if ((s->pi->flags & capa_to_assert) != capa_to_assert) {
+        hw_error("m25p80: %dk erase size not supported by device\n", len);
+    }
+
+    if (!s->write_enable) {
+        DB_PRINT("erase with write protect!\n");
+        return;
+    }
+    memset(s->storage + offset, 0xff, len);
+    flash_sync_area(s, offset, len);
+}
+
+static inline void flash_sync_dirty(Flash *s, int64_t newpage)
+{
+    if (s->dirty_page >= 0 && s->dirty_page != newpage) {
+        flash_sync_page(s, s->dirty_page);
+        s->dirty_page = newpage;
+    }
+}
+
+static inline
+void flash_write8(Flash *s, uint64_t addr, uint8_t data)
+{
+    int64_t page = addr / s->pi->page_size;
+    uint8_t prev = s->storage[s->cur_addr];
+
+    if (!s->write_enable) {
+        DB_PRINT("write with write protect!\n");
+    }
+
+    if ((prev ^ data) & data) {
+        DB_PRINT("programming zero to one! addr=%lx  %x -> %x\n",
+                  addr, prev, data);
+    }
+
+    if (s->pi->flags & WR_1) {
+        s->storage[s->cur_addr] = data;
+    } else {
+        s->storage[s->cur_addr] &= data;
+    }
+
+    flash_sync_dirty(s, page);
+    s->dirty_page = page;
+}
+
+static void complete_collecting_data(Flash *s)
+{
+    s->cur_addr = s->data[0] << 16;
+    s->cur_addr |= s->data[1] << 8;
+    s->cur_addr |= s->data[2];
+
+    switch (s->cmd_in_progress) {
+    case PP:
+        s->state = STATE_PAGE_PROGRAM;
+        break;
+    case READ:
+    case FAST_READ:
+        s->state = STATE_READ;
+        break;
+    case ERASE_4K:
+    case ERASE_32K:
+    case ERASE_SECTOR:
+        flash_erase(s, s->cur_addr, s->cmd_in_progress);
+        break;
+    default:
+        break;
+    }
+}
+
+static void decode_new_cmd(Flash *s, uint32_t value)
+{
+    s->cmd_in_progress = value;
+    DB_PRINT("decoded new command:%x\n", value);
+
+    switch (value) {
+
+    case ERASE_4K:
+    case ERASE_32K:
+    case ERASE_SECTOR:
+    case READ:
+    case PP:
+        s->needed_bytes = 3;
+        s->pos = 0;
+        s->len = 0;
+        s->state = STATE_COLLECTING_DATA;
+        break;
+
+    case FAST_READ:
+        s->needed_bytes = 4;
+        s->pos = 0;
+        s->len = 0;
+        s->state = STATE_COLLECTING_DATA;
+        break;
+
+    case WRDI:
+        s->write_enable = false;
+        break;
+    case WREN:
+        s->write_enable = true;
+        break;
+
+    case RDSR:
+        s->data[0] = (!!s->write_enable) << 1;
+        s->pos = 0;
+        s->len = 1;
+        s->state = STATE_READING_DATA;
+        break;
+
+    case JEDEC_READ:
+        DB_PRINT("populated jedec code\n");
+        s->data[0] = (s->pi->jedec >> 16) & 0xff;
+        s->data[1] = (s->pi->jedec >> 8) & 0xff;
+        s->data[2] = s->pi->jedec & 0xff;
+        if (s->pi->ext_jedec) {
+            s->data[3] = (s->pi->ext_jedec >> 8) & 0xff;
+            s->data[4] = s->pi->ext_jedec & 0xff;
+            s->len = 5;
+        } else {
+            s->len = 3;
+        }
+        s->pos = 0;
+        s->state = STATE_READING_DATA;
+        break;
+
+    case BULK_ERASE:
+        if (s->write_enable) {
+            DB_PRINT("chip erase\n");
+            flash_erase(s, 0, BULK_ERASE);
+        } else {
+            DB_PRINT("chip erase with write protect!\n");
+        }
+        break;
+    case NOP:
+        break;
+    default:
+        DB_PRINT("Unknown cmd %x\n", value);
+        break;
+    }
+}
+
+static int m25p80_cs(SSISlave *ss, bool select)
+{
+    Flash *s = FROM_SSI_SLAVE(Flash, ss);
+
+    if (select) {
+        s->len = 0;
+        s->pos = 0;
+        s->state = STATE_IDLE;
+        flash_sync_dirty(s, -1);
+    }
+
+    DB_PRINT("%sselect\n", select ? "de" : "");
+
+    return 0;
+}
+
+static uint32_t m25p80_transfer8(SSISlave *ss, uint32_t tx)
+{
+    Flash *s = FROM_SSI_SLAVE(Flash, ss);
+    uint32_t r = 0;
+
+    switch (s->state) {
+
+    case STATE_PAGE_PROGRAM:
+        DB_PRINT("page program cur_addr=%lx data=%x\n", s->cur_addr,
+                 (uint8_t)tx);
+        flash_write8(s, s->cur_addr, (uint8_t)tx);
+        s->cur_addr++;
+        break;
+
+    case STATE_READ:
+        r = s->storage[s->cur_addr];
+        DB_PRINT("READ 0x%lx=%x\n", s->cur_addr, r);
+        s->cur_addr = (s->cur_addr + 1) % s->size;
+        break;
+
+    case STATE_COLLECTING_DATA:
+        s->data[s->len] = (uint8_t)tx;
+        s->len++;
+
+        if (s->len == s->needed_bytes) {
+            complete_collecting_data(s);
+        }
+        break;
+
+    case STATE_READING_DATA:
+        r = s->data[s->pos];
+        s->pos++;
+        if (s->pos == s->len) {
+            s->pos = 0;
+            s->state = STATE_IDLE;
+        }
+        break;
+
+    default:
+    case STATE_IDLE:
+        decode_new_cmd(s, (uint8_t)tx);
+        break;
+    }
+
+    return r;
+}
+
+static int m25p80_init(SSISlave *ss)
+{
+    DriveInfo *dinfo;
+    Flash *s = FROM_SSI_SLAVE(Flash, ss);
+    const FlashPartInfo *i;
+
+    if (!s->part_name) { /* default to actual m25p80 if no partname given */
+        s->part_name = (char *)"m25p80";
+    }
+
+    i = known_devices;
+    for (i = known_devices;; i++) {
+        assert(i);
+        if (!i->part_name) {
+            fprintf(stderr, "Unknown SPI flash part: \"%s\"\n", s->part_name);
+            return 1;
+        } else if (!strcmp(i->part_name, s->part_name)) {
+            s->pi = i;
+            break;
+        }
+    }
+
+    s->size = s->pi->sector_size * s->pi->n_sectors;
+    s->dirty_page = -1;
+    s->storage = qemu_blockalign(s->bdrv, s->size);
+
+    dinfo = drive_get_next(IF_MTD);
+
+    if (dinfo && dinfo->bdrv) {
+        DB_PRINT("Binding to IF_MTD drive\n");
+        s->bdrv = dinfo->bdrv;
+        /* FIXME: Move to late init */
+        if (bdrv_read(s->bdrv, 0, s->storage, DIV_ROUND_UP(s->size,
+                                                    BDRV_SECTOR_SIZE))) {
+            fprintf(stderr, "Failed to initialize SPI flash!\n");
+            return 1;
+        }
+    } else {
+        memset(s->storage, 0xFF, s->size);
+    }
+
+    return 0;
+}
+
+static void m25p80_pre_save(void *opaque)
+{
+    flash_sync_dirty((Flash *)opaque, -1);
+}
+
+static const VMStateDescription vmstate_m25p80 = {
+    .name = "xilinx_spi",
+    .version_id = 1,
+    .minimum_version_id = 1,
+    .minimum_version_id_old = 1,
+    .pre_save = m25p80_pre_save,
+    .fields = (VMStateField[]) {
+        VMSTATE_UINT8(state, Flash),
+        VMSTATE_UINT8_ARRAY(data, Flash, 16),
+        VMSTATE_UINT32(len, Flash),
+        VMSTATE_UINT32(pos, Flash),
+        VMSTATE_UINT8(needed_bytes, Flash),
+        VMSTATE_UINT8(cmd_in_progress, Flash),
+        VMSTATE_UINT64(cur_addr, Flash),
+        VMSTATE_BOOL(write_enable, Flash),
+        VMSTATE_END_OF_LIST()
+    }
+};
+
+static Property m25p80_properties[] = {
+    DEFINE_PROP_STRING("partname", Flash, part_name),
+    DEFINE_PROP_END_OF_LIST(),
+};
+
+static void m25p80_class_init(ObjectClass *klass, void *data)
+{
+    DeviceClass *dc = DEVICE_CLASS(klass);
+    SSISlaveClass *k = SSI_SLAVE_CLASS(klass);
+
+    k->init = m25p80_init;
+    k->transfer = m25p80_transfer8;
+    k->set_cs = m25p80_cs;
+    k->cs_polarity = SSI_CS_LOW;
+    dc->props = m25p80_properties;
+    dc->vmsd = &vmstate_m25p80;
+}
+
+static const TypeInfo m25p80_info = {
+    .name           = "m25p80",
+    .parent         = TYPE_SSI_SLAVE,
+    .instance_size  = sizeof(Flash),
+    .class_init     = m25p80_class_init,
+};
+
+static void m25p80_register_types(void)
+{
+    type_register_static(&m25p80_info);
+}
+
+type_init(m25p80_register_types)