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:

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

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
			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¶

cp: baseband processor

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.

TODO¶

check gpio_flm_uart_sel in smdk4412 kernel too

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:

https://git.replicant.us/replicant/external_libsamsung-ipc/tree/samsung-ipc/devices/i9300/i9300.h?id=9ff9785a7f48e32f107ca7fb2e298b1320ad4cbc
https://git.replicant.us/replicant/external_libsamsung-ipc/tree/samsung-ipc/devices/n7100/n7100.h?id=9ff9785a7f48e32f107ca7fb2e298b1320ad4cbc
Verified on GT-I9300 and GT-N7100 modem partition 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¶

GT-I9250