h1. GT-P3100Bootloader

{{toc}}

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