hw/avr: Prepare for TARGET_PAGE_SIZE > 256

If i/o does not cover the entire first page, allocate a portion
of ram as an i/o device, so that the entire first page is i/o.

While memory_region_init_ram_device_ptr is happy to allocate
the RAMBlock, it does not register the ram for migration.
Do this by hand.

Reviewed-by: Pierrick Bouvier <pierrick.bouvier@linaro.org>
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>

1 files changed, 1 insertions, 0 deletions

diff --git a/hw/avr/atmega.h b/hw/avr/atmega.h
index a99ee15c7e..9ac4678231 100644
--- a/hw/avr/atmega.h
+++ b/hw/avr/atmega.h
@@ -41,6 +41,7 @@ struct AtmegaMcuState {
     MemoryRegion flash;
     MemoryRegion eeprom;
     MemoryRegion sram;
+    MemoryRegion sram_io;
     DeviceState *io;
     AVRMaskState pwr[POWER_MAX];
     AVRUsartState usart[USART_MAX];