On 07/04/2016 07:57 PM, mar.krzeminski wrote:
>
>
> W dniu 04.07.2016 o 14:18, Cédric Le Goater pisze:
>> Some SPI controllers, such as the Aspeed AST2400, have a mode in which
>> accesses to the flash content are no different than doing MMIOs. The
>> controller generates all the necessary commands to load (or store)
>> data in memory.
>>
>> To emulate such a behavior, we need to have access to the underlying
>> storage of the flash object. The purpose of the routine is to set the
>> storage of a preinitialized SPI flash object, which can then be used
>> by the object itself but also by a SPI controller to handled the
>> MMIOs.
> Hi,
>
> I am not sure if this approach is correct. I can not find any datasheet
> to this SPI controller, but as you mentioned in first paragraph, controller
> generates all commands (probably ones are somehow configurable).
yes. see this patch :
http://lists.nongnu.org/archive/html/qemu-devel/2016-06/msg08229.html
/* CEx Control Register */
#define R_CTRL0 (0x10 / 4)
#define CTRL_CMD_SHIFT 16
#define CTRL_CMD_MASK 0xff
> In this series you hack this behaviour and you do direct access to file.
It is true it is not very respectful of the m25p80 interface.
> IMHO you should emulate sending such commands in SPI controller
> model.
I will give it a try. I don't think the alternative is a complex
change anyhow.
Thanks,
C.
> Thanks,
> Marcin
>
>> This is sufficient to support read only accesses. For writes, we would
>> certainly need to externalize flash_write8() routine.
>>
>> Signed-off-by: Cédric Le Goater <c...@kaod.org>
>> ---
>> hw/block/m25p80.c | 14 +++++++++++++-
>> include/hw/block/flash.h | 2 ++
>> 2 files changed, 15 insertions(+), 1 deletion(-)
>>
>> diff --git a/hw/block/m25p80.c b/hw/block/m25p80.c
>> index aa964280beab..fec0fd4c2228 100644
>> --- a/hw/block/m25p80.c
>> +++ b/hw/block/m25p80.c
>> @@ -29,6 +29,7 @@
>> #include "qemu/bitops.h"
>> #include "qemu/log.h"
>> #include "qapi/error.h"
>> +#include "hw/block/flash.h"
>> #ifndef M25P80_ERR_DEBUG
>> #define M25P80_ERR_DEBUG 0
>> @@ -1152,7 +1153,11 @@ static void m25p80_realize(SSISlave *ss, Error **errp)
>> if (s->blk) {
>> DB_PRINT_L(0, "Binding to IF_MTD drive\n");
>> - s->storage = blk_blockalign(s->blk, s->size);
>> +
>> + /* using an external storage. see m25p80_create_rom() */
>> + if (!s->storage) {
>> + s->storage = blk_blockalign(s->blk, s->size);
>> + }
>> if (blk_pread(s->blk, 0, s->storage, s->size) != s->size) {
>> error_setg(errp, "failed to read the initial flash content");
>> @@ -1259,3 +1264,10 @@ static void m25p80_register_types(void)
>> }
>> type_init(m25p80_register_types)
>> +
>> +void m25p80_set_rom_storage(DeviceState *dev, MemoryRegion *rom)
>> +{
>> + Flash *s = M25P80(dev);
>> +
>> + s->storage = memory_region_get_ram_ptr(rom);
>> +}
>> diff --git a/include/hw/block/flash.h b/include/hw/block/flash.h
>> index 50ccbbcf1352..9d780f4ae0c9 100644
>> --- a/include/hw/block/flash.h
>> +++ b/include/hw/block/flash.h
>> @@ -61,4 +61,6 @@ uint8_t ecc_digest(ECCState *s, uint8_t sample);
>> void ecc_reset(ECCState *s);
>> extern VMStateDescription vmstate_ecc_state;
>> +void m25p80_set_rom_storage(DeviceState *dev, MemoryRegion *rom);
>> +
>> #endif
>
