h1. XMMBoot

h2.  Introduction

For both libsamsung-ipc and the Linux driver it's interesting to understand better the boot of the modem in order to come with good names for the abstraction.

The GPIO platform data names were taken from the "modem_modemctl_device_xmm6260.c":https://git.replicant.us/replicant/kernel_samsung_smdk4412/tree/drivers/misc/modem_if/modem_modemctl_device_xmm6260.c file

|_. ioctl name |_. function pointer name |_. gpio platform data name |_. present |_. absent |_. comments |
| | | gpio_cp_on | | | cp == baseband processor |
| | | gpio_reset_req_n | |
| | | gpio_cp_reset | | | cp == baseband processor |
| | | gpio_pda_active | |
| | | gpio_phone_active | |
| | | gpio_cp_dump_int | | | cp == baseband processor |
| | | gpio_flm_uart_sel | Galaxy Nexus | Not used in libsamsung-ipc for other Replicant compatible devices | Modem download mode ? |
| IOCTL_MODEM_BOOT_ON
IOCTL_MODEM_BOOT_OFF | modem_boot_on
modem_boot_off | gpio_cp_warm_reset | | |  cp == baseband processor  |
| | | gpio_revers_bias_clear | | | |
| | | gpio_revers_bias_restore | | | |
| | | gpio_sim_detect | | | Detect SIM card presence ? |

h2. SIM card presence detection

Do we really want to check the SIM card presence?

Would it be possible not to for privacy reasons?

Example:
* Boot a modem with a SIM
* Take away the SIM card
* Go to a protest with only the SIM card and a phone with no data on it to be able to call if necessary.

h2. TODO

* check gpio_flm_uart_sel in smdk4412 kernel too

h2. Links

* https://git.replicant.us/replicant/kernel_samsung_smdk4412/tree/drivers/misc/modem_if/modem_modemctl_device_xmm6260.c
* https://forum.xda-developers.com/galaxy-s2/help/how-to-talk-to-modem-commands-t1471241/page4