Replicant

h1. GT-P3100Bootloader

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At boot, when pressing the power button for a short time we get:

<pre>

$ picocom -b 115200 /dev/ttyUSB1 

picocom v3.1

port is        : /dev/ttyUSB1

flowcontrol    : none

baudrate is    : 115200

parity is      : none

databits are   : 8

stopbits are   : 1

escape is      : C-a

local echo is  : no

noinit is      : no

noreset is     : no

hangup is      : no

nolock is      : no

send_cmd is    : sz -vv

receive_cmd is : rz -vv -E

imap is        : 

omap is        : 

emap is        : crcrlf,delbs,

logfile is     : none

initstring     : none

exit_after is  : not set

exit is        : no

Type [C-a] [C-h] to see available commands

Terminal ready

Texas Instruments X-Loader 1.41 (Jun 13 2012 - 22:11:09)

Uboot-loading from Emmc

Starting OS Bootloader from EMMC ...

</pre>

Here the device boots, but if the button isn't pressed long enough it shuts down.

When pressing it for a longer time we get:

<pre>

$ picocom -b 115200 /dev/ttyUSB1 

picocom v3.1

port is        : /dev/ttyUSB1

flowcontrol    : none

baudrate is    : 115200

parity is      : none

databits are   : 8

stopbits are   : 1

escape is      : C-a

local echo is  : no

noinit is      : no

noreset is     : no

hangup is      : no

nolock is      : no

send_cmd is    : sz -vv

receive_cmd is : rz -vv -E

imap is        : 

omap is        : 

emap is        : crcrlf,delbs,

logfile is     : none

initstring     : none

exit_after is  : not set

exit is        : no

Type [C-a] [C-h] to see available commands

Terminal ready

Texas Instruments X-Loader 1.41 (Jun 13 2012 - 22:11:09)

Uboot-loading from Emmc

Starting OS Bootloader from EMMC ...

g_nRebootReason = 0x100000

Kernel  @ 81808000 (4524144 bytes)

Ramdisk @ 82800000 (994957 bytes)

set_lcd_panel_id: panel_adc=805

*** ltn070nl01_power_on ***

lcd_pannel_id=3

AST_POWERON

</pre>

Here @AST_POWERON@ probably means that there is a GPIO that can switch between the OMAP4 UART and the modem UART, and that at some point during the boot it's switched to the modem.

I tried to type AT commands like @AT@ but I got no response. Maybe it's because I use the wrong voltage for the UART. Maybe I need to reset the modem through AT commands.

TODO:

* Measure the UART voltage somehow (output only ones and try to measure it)

* Try to see if it responds to AT reset and verbose commands