Hi,
I have A5-V11 with EM63A165TS-6G (32MB Ram) and I flashed uboot256 and openwrt after uboot says:

Board Ralink APSoC DRAM  16 MB
relocate_code Pointer at 80fb4000

Software System Reset Occurred

spi_wait_nsec 42
spi device id 7f 9d 46 7f 9d (9d467f9d)
Warning un-recognized chip ID, please update bootloader!
raspi_read from30000 len1000
.raspi_read from30000 len1000
.============================================
Ralink UBoot Version 3.6.0.0
--------------------------------------------
ASIC 5350_MP (Port5-None)
DRAM_CONF_FROM Boot-Strapping
DRAM_TYPE SDRAM
DRAM_SIZE 128 Mbits
DRAM_WIDTH 16 bits
DRAM_TOTAL_WIDTH 16 bits
TOTAL_MEMORY_SIZE 16 MBytes
Flash component SPI Flash
DateJul 31 2013  Time233504
============================================
icache sets256, ways4, linesz32 ,total32768
dcache sets128, ways4, linesz32 ,total16384

##### The CPU freq = 360 MHZ ####
estimate memory size =16 Mbytes

And I don't know what can I do. I tried reflash uboot and still not work.
Can somebody help?

For rt5350 chipset openwrt read memory size from (incorrect) bootstrap settings and ignore value passed by uboot.
You can force 32MB memory size by adding

        memory@0 {
                device_type = "memory";
                reg = <0x0 0x2000000>;
       };

into your dts-file.
For details google with keywords "openwrt dts memory".