need help to modify a bios dumped from set-top box

[jason0503]

The set-top box has a TV silicon tuner IC MXL608, which has a programmable channel selection filter (6MHz/7MHz/8MHz), and the default value is 8MHZ, but the manufacturer sets the set-top box to 6MHZ. How can I change this value by modifying the dumped bios? I tried using UEFITool.exe, but it doesn't work. The BIOS of the TV box is different from that of the computer. I don't know how to modify it or what tool to use. I downloaded the data sheet of MXL608, which mentioned that when the value of SYMBOL is set to 2.85, BW=6MHZ. When the value of SYMBOL is 3.75, BW=8MHZ, but I can't find the corresponding place after opening the BIN file with HDX. Please help me, thank you
mxl608 IC datasheet


dumped bios

[Diah]

first of all need to know the system installed on the box , open source or closed one....
BTW what are the brand of the box... by advanced setting and manual scan i think you can set the Freq you are wishing to receive

[jason0503]

Thanks for your reply. The brand of this set-top box is gelect. Sorry I am not sure what operating system it is, but there is no information about the Android version in the system information. In addition, it should not be open source. There is no option to change the bandwidth in the system settings. I have searched and there is no such option. When searching for signals, the default setting is 6MHZ and cannot be changed. This is a system composed chips of MSD7831 8880 60X chips.

[Diah]

but there is no information about the Android version in the system information. .

you are talking on Android... android are open source... only the DVBAPI some brands close it to avoid open paid channel ..
please post system Info screen shoot.. and the setting menu from it could know which android ita is..

if you can dump the boot section.. will be helpful , or if you can root it so you can have to hidden file xml related to DVB program there can be changed too.
i put here apk if you can install it by sideloaded ADB or direct with usb
..

[lotas]

Well, what kind of android is there with a MSD7831 cpu, rather an ordinary digital set-top box for TV and dump there on a regular spi flash 25Q32 (64). Why does Android need a TV tuner?

[Diah]

Well, what kind of android is there with a MSD7831 cpu, rather an ordinary digital set-top box for TV and dump there on a regular spi flash 25Q32 (64). Why does Android need a TV tuner?

i think he did mistake.. Android never installed on spi or eeprom.. it only on SSD / eMMC / NAND. , tuner on android its good things i do have 2 set box android 7.1.2 with tuners.. one with T2/C/SAT, the other only SAT. so i can watch all scramble channel via SAT and C via OSCAM.

[jason0503]

i think he did mistake.. Android never installed on spi or eeprom.. it only on SSD / eMMC / NAND. , tuner on android its good things i do have 2 set box android 7.1.2 with tuners.. one with T2/C/SAT, the other only SAT. so i can watch all scramble channel via SAT and C via OSCAM.

i can boot into uboot now and get some message ,any ideas ?

u32TunerFreq = -1 u8BandWidth = -1
1 3 1
Tuner locked
MxL608_0x5B : 10
MxL608_0x5C : b1
MxL608_0xC2 : a9
1 3 0

console out .txt

[Diah]

yours UNIX MSTAR. its open and the firmware key easly to find for extraction and recompile change, try find firmware for yours box and use MSTAR tool to do the change for Demode List.

[jason0503]

yours UNIX MSTAR. its open and the firmware key easly to find for extraction and recompile change, try find firmware for yours box and use MSTAR tool to do the change for Demode List.

MSTAR tool unpacking error occurred 'UnicodeDecodeError: 'utf-8' codec can't decode byte 0xbf in position 4097'. This set-top box does not have a FLASH storage chip. Does the MSD7831 have an integrated FLASH hard disk? I uploaded the firmware

gelect__31-05-16v26-upgrade.rar

[jason0503]

This model has no NAND on the motherboard, I confirm

[Diah]

its look closed at module
" line 42, in <module>
offset = header.find('\xff'.encode(encoding='iso-8859-1'))
UnicodeDecodeError: 'ascii' codec can't decode byte 0xff in position 0: ordinal not in range(128)"

try on linux machine.. my i don't have right now under hand.

[jason0503]

its look closed at module
" line 42, in <module>
offset = header.find('\xff'.encode(encoding='iso-8859-1'))
UnicodeDecodeError: 'ascii' codec can't decode byte 0xff in position 0: ordinal not in range(128)"

try on linux machine.. my i don't have right now under hand.

Many people have encountered similar problems
https://github.com/dipcore/mstar-bin-tool/issues/20

[jason0503]

its look closed at module
" line 42, in <module>
offset = header.find('\xff'.encode(encoding='iso-8859-1'))
UnicodeDecodeError: 'ascii' codec can't decode byte 0xff in position 0: ordinal not in range(128)"

try on linux machine.. my i don't have right now under hand.

Add three lines at the beginning of unpack.py ( python versions below 3.0):
import sys
reload(sys)
sys.setdefaultencoding('iso-8859-1')

but is nothing useful out ,a header and header_script out in unpacked folder ,no Demode List?
[i] Analizing header ...
[i] Saving header script to unpacked\~header_script ...
[i] Parsing script ...
[i] Parsing setenv usb_complete -> 1
[i] Parsing setenv usb_upgrade -> 0
[i] Parsing setenv bootcmd -> ' spi_rdc 0x80b00000 0xa001c 0x2b6d8b; LzmaDec 0x80b00000 0x2b6d8b 0x80000180 0x81000000; go 0x80000224;
[i] Done.

[Diah]

MSTAR tool had limited , but when you work on Linux machine, "binwalk" can do more effective

[jason0503]

MSTAR tool had limited , but when you work on Linux machine, "binwalk" can do more effective

I used binwalk to extract the files（here）, but it didn't seem to work.