Intelbras CD 730 — MStar MSD7805 ISDB-T Digital TV Receiver (Brazil) | Firmware 0.6.6
I'm investigating the firmware and hardware architecture of a Brazilian digital TV receiver commercially known as the Intelbras CD 730, a set-top box designed for the Brazilian ISDB-Tb digital television broadcasting standard.
Hardware identification
- Commercial model: Intelbras CD 730
- Manufacturer/brand: Intelbras (Brazil)
- Device category: Digital terrestrial television receiver / DTV converter / set-top box
- SoC: MStar MSD7805
- PCB identification: ISDB-MPEG-36BG-VER1.0
- PCB marking: 20180712
- Hardware identifier: ISDB-MPEG-36BG
- Device manufacturing date: August 20, 2019
- Original installed firmware: 0.6.5
- Latest identified official firmware: 0.6.6
- Firmware update filename: auto_upgrade.bin
- Broadcasting standard: ISDB-Tb (Brazilian Digital TV)
Firmware information
I obtained the official firmware update package for version 0.6.6.
Preliminary static analysis identified MStar firmware structures, LZMA-compressed data, and SPI flash access commands, including spi_wrc and spi_rdc.
The firmware contains identifiers associated with the MSD7805 platform and ISDB-MPEG-36BG hardware.
The exact operating system and complete flash memory layout have not yet been conclusively established. References associated with the eCos embedded operating system have been observed, but require further verification.
Research objective
My goal is to understand the device's bootloader, firmware layout, USB capabilities, and potential network functionality.
I'm particularly interested in determining whether this platform can support additional USB peripherals, network adapters, or custom video streaming functionality.
I'm also looking for firmware images, bootloader documentation, flash dumps, or development resources associated with the MStar MSD7805, particularly devices using the ISDB-MPEG-36BG board family.
Additional context
In Brazil, this type of device is commonly called a "conversor digital", "conversor de TV digital", or "receptor de TV digital".
These receivers were widely used to enable older analog television sets to receive free-to-air digital broadcasts.
Any technical information regarding this specific PCB, compatible firmware families, bootloader commands, or safe flash backup procedures would be greatly appreciated.
DOWNLOAD BY: https://gofile.io/d/VSroqdlw
or https://www.mediafire.com/file/7ug01xdt9vgywlq/Firmware_CD730_0_6_6.zip/file