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Modem-CPU Interface in Galaxy S3
Added by Uli . about 11 years ago
I am not sure where to put this question, but as it is quite low-level, I think this might be an ok place.
I would like to know which hardware interface is used to connect the modem of the S3 to the application processor, esp regarding which control and access possibilities the modem has on the main RAM.
I tried reading through all the manuals and schematics I could find, but do not seem to find reliable information.
I was hoping you could help me out here, seeing that you implemented quite low level stuff for replicant.
I also tried to locate the driver to check for myself, but as I am not familiar with neither the linux kernel nor android, I failed here. I would be glad if you could also point me to the location of the S3 modem driver.
Replies (1)
RE: Modem-CPU Interface in Galaxy S3 - Added by Paul Kocialkowski about 11 years ago
The hardware interface is HSIC, which is High Speed USB. There should be no access to the RAM involved, yet we cannot know for sure. The diagrams from the service manual reveal that the GPS might be connected to the modem IIRC.
tried to locate the driver to check for myself, but as I am not familiar with neither the linux kernel nor android, I failed here. I would be glad if you could also point me to the location of the S3 modem driver.
The relevant transport file for HSIC should be: https://gitorious.org/replicant/kernel_samsung_smdk4412/source/792bf04d04ba529e6aa1267eeae5361e02980f28:drivers/misc/modem_if/modem_link_device_hsic.c
You can check in the I9300 defconfig that it's what's being used: https://gitorious.org/replicant/kernel_samsung_smdk4412/source/792bf04d04ba529e6aa1267eeae5361e02980f28:arch/arm/configs/cyanogenmod_i9300_defconfig#L1311