Table of Contents
Advertisement
4.3.
Firmware boot up flow
When source code is compiled the compiler generates MT7681_all.bin. — the software for
MT7681. This software consists of four images that provide features related to Loader,
Recover/Calibration, Station, and AP as described in Table 10.
Function
Loader
Recovery/Calibration
Station
Access point (AP)
4.3.1.
Boot up Sequence
The boot up flow for the MT7681, as shown in Figure 20, is as follows:
1)
Power on
MT7681 powers on and loads "Loader image"
2) Loader
"Loader image" loads "Recovery Image" from Flash to SRAM. MT7681 then jumps to SRAM
address 0 and starts to run.
3) Recovery/Calibration Mode
"Recovery/Calibration Image" will start a 4 seconds timer and wait for a command from
UART.
If no command is received before the timer expires, MT7681 proceeds to determining
o
whether to load Station or AP mode.
If AT#UpdateFW is received on the UART, MT7681 goes to recovery mode and starts the
o
X-modem protocol to wait new firmware. Using the firmware uploader, you can write
new firmware with header content (MT7681_sta_header.bin or
MT7681_ap_header.bin) to MT7681. For more details, see section 3.2, "Firmware
uploader".
4) Determined Station or AP mode
"Loader image" reads the "Firmware Boot Index" setting stored in Flash (stored in the
Flash offset: 0x18001):, and load "station image" or "AP image" to SRAM:
If the value is 0x00 or 0xFF, "station image" is loaded to SDRAM.
o
If the value is 0x01, "AP image" is loaded to SDRAM.
o
It is possible to change the value of "Firmware Boot Index" during Recovery mode by
sending the AT command AT#FLASH -s0x18001 -vX where X is the new index value.
5) Station mode
When "Station Image" is loaded, MT7681 is in station mode, it can connect to an AP-router,
and create TCP/UDP connection with other devices in the LAN or WLAN
6) AP mode
When "AP Image" is loaded, MT7681 is in AP mode. Other station devices (phone, tablet, or
This document contains information that is proprietary to MediaTek Inc.
Unauthorized reproduction or disclosure of this information in whole or in part is strictly prohibited.
MediaTek LinkIt™ Connect 7681 Developer's Guide
Image name
MT7681_loader.bin
MT7681_recovery_old.bin Responsible for firmware upgrade by
MT7681_sta.bin
MT7681_ap.bin
Table 10 The four MT7681 software images
© 2015, 2016 MediaTek Inc.
Purpose
Responsible for loading images from
Flash to SRAM
UART and power and frequency
calibration on the factory production line.
Image for Station mode.
Image for AP mode.
Page 27 of 65
Advertisement
Table of Contents
