What's the smallest embedded linux distro?

[Aljh]

I like to ask to the experts out there.. What is the best embedded linux distro for:

Flash memory ~ 700Kb
Ram ~ 256Kb
Processor: High end arm cortex STM32F103C8T6 (something from STM32 family for eg)
Required modules: - Kernel core - Basic driver set: USB/Networking (for WiFi - No AP, just client, no security)/SPI/Uart/I2C

Is this at all possible or am I dreaming?

The idea is to use a 5$ high end CortexM3 and don't use any external memories so that I can enjoy the ready drivers for SDIO/WiFi etc.

I updated the question with clarification on WiFi. WiFi in the sense that it is a simple, run of the mill client. Nothing fancy, perhaps wep if I can fit it.
Another update: How about uCLinux?

 

[pearce_jj]

I would look at something with 32/32MB then use OpenWRT. Or buy a Raspberry Pi Zero for £4 and run Raspbian or full Ubuntu.

 

[eeguru]

Even Linux 2.4/2.6 will require 3+ MB of RAM to get a kernel up with a bit left over to do anything practical. Try reserching BSD. I recall the MIPS R4Ke port fitting in a rediculously small footprint on a PIC32.

 

[gertk]

Or for a tiny microcontroller with WiFi (client, host and AP) take a look at the ESP8266, you can reprogram them with the Arduino IDE and keep all the WiFi stuff active.

 

[Chuck(G)]

The STM32F103 is a bit small for this kind of thing. I imagine that you're looking at one of the Chinese import mini-boards. They're very useful as Arduino step-up, but I don't think that even a tiny distro like BusyBox is going to give you much useful functionality. You're beter off, if Linux is your goal, spending $10 for an Orange Pi One, which is certainly capable.