XMMBoot

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.

GPIOs

Devices GPIOs

Variant SOC Modem GPIO usage GPIO assignement
GT-I9300 Exynos 4412 XMM6262 CONFIG_UMTS_MODEM_XMM6262=y
Makefile
modem_modemctl_device_xmm6262.c 		CONFIG_SEC_MODEM_M0=y
Makefile
board-m0-modems.c
CONFIG_MACH_M0=y
gpio-midas.h
gpio-rev00-m0.h

Libsamsung-ipc

ioctl / function Devices
GT-I9100 GT-I9250 (maguro) GT-I9300 GT-N5100 GT-N7100 GT-P3100 / GT-P5100 (piranah)
open, close, read, write
fmt/rfs
gprs
power 		All devices
boot_power
status_online_wait 		No Yes No
hci_power
link_control_enable
link_control_active
link_control_wait
link_get_hostwake_wait 		Yes No Yes No

The GPIO platform data names were taken from the modem_modemctl_device_xmm6262.c file

libsamsung-ipc Kernel Devices Documentation
Function using the ioctl ioctl name function pointer name gpio platform data name present absent Implementation comments
xmm626_kernel_smdk4412_power IOCTL_MODEM_ON
IOCTL_MODEM_OFF 		modem_on
modem_off 		gpio_cp_on powers on the modem? in which state (PMIC?, CPU?)
* On GT-I9100 it's connected to the ON1 modem pin and ON2 is not connected.
gpio_cp_reset Resets the modem CPU? PMIC?:
* ''check the reset timming with C2C connection'' : Here C2C probably means chip to chip
Can also read the modem CPU? and/or PMIC? reset state?
* Reads from the GPIO and ''CP not ready, Active State low'' comment
gpio_reset_req_n
gpio_pda_active Tell the modem if the SOC CPUs are sleeping/active or not?
* PDA == Application processor
* ''PDA_ACTIVE, let cp know AP sleep'' comment in status gc1-gpio.c
* PDA_ACTIVE set to 0 right after cpu_pm_enter()
* PDA_ACTIVE set to 1 right before cpu_pm_exit()
* GPIO direction is output on AP side and input on BP side, which is also confirmed by the pinout table in XDA
gpio_phone_active
gpio_cp_dump_int cp: baseband processor
xmm626_kernel_smdk4412_boot_power IOCTL_MODEM_BOOT_ON
IOCTL_MODEM_BOOT_OFF 		modem_boot_on
modem_boot_off 		gpio_flm_uart_sel Only used for the Galaxy Nexus in libsamsung-ipc Modem download mode ?
gpio_cp_warm_reset cp: baseband processor
gpio_revers_bias_clear
gpio_revers_bias_restore
gpio_sim_detect Detect SIM card presence ?

Glossary

SIM card presence detection

Do we really want to check the SIM card presence?

Would it be possible not to for privacy reasons?

Example:

TODO

Modem partitions

GT-I9300, GT-N7100

Location Name Content
[ 0x0 -> 0xfff ] ? Partition table?
[ 0x1000 -> 0xefff ] PSIRAM First stage bootloader?
[ 0xF000 -> 0x27fff ] EBL Second stage bootloader ?
[ 0x28000 -> 0x9ff7ff ] MAIN ?
[ 0x9ff800 -> 0x9fffff ] SECPACK ?
[ 0xa00000 -> 0xbfffff ] NV ?
References for the table:

GT-I9300 and GT-N7100 modem partition table dump

$ hexdump -C RADIO.img
00000000  50 53 49 52 41 4d 00 00  00 00 00 00 00 10 00 00  |PSIRAM..........|
00000010  00 00 00 00 00 e0 00 00  00 00 00 00 00 00 00 00  |................|
00000020  45 42 4c 00 00 00 00 00  00 00 00 00 00 f0 00 00  |EBL.............|
00000030  00 00 00 60 00 90 01 00  00 00 00 00 00 00 00 00  |...`............|
00000040  4d 41 49 4e 00 00 00 00  00 00 00 00 00 80 02 00  |MAIN............|
00000050  00 00 30 60 00 78 9d 00  00 00 00 00 00 00 00 00  |..0`.x..........|
00000060  53 45 43 50 41 43 4b 00  00 00 00 00 00 f8 9f 00  |SECPACK.........|
00000070  00 00 00 00 00 08 00 00  00 00 00 00 00 00 00 00  |................|
00000080  4e 56 00 00 00 00 00 00  00 00 00 00 00 00 a0 00  |NV..............|
00000090  00 00 e8 60 00 00 20 00  00 00 00 00 00 00 00 00  |...`.. .........|
000000a0  00 00 00 00 00 00 00 00  00 00 00 00 00 00 00 00  |................|
*
[...]

Devices without a partition table or with a different one

Links