Qualcomm Kernel » History » Revision 4
Revision 3 (laforge, 10/01/2016 03:51 PM) → Revision 4/22 (laforge, 10/01/2016 03:52 PM)
h1. Qualcomm Kernel
Random notes about the Qualcomm Kernel as used on the MDM9615
h2. diag
h3. diag forwarding
<pre>
drivers/char/diag/diagfwd.[ch]
drivers/usb/gadget/f_diag.[ch]
drivers/usb/misc/diag_bridge.c
</pre>
* the usb diag gadget handles diag packet read/write over usb
* issues events like USB_DIAG_READ_DONE
* picked up by diagfwd.c
** can forward diag requests via SMD shared memory to other processors
h3. diag char
<pre>
drivers/char/diag/diagchar_core.c
</pre>
* ioctl()s for diag configuration
* supports several concurrent diag clients
* diag logging can be directed to USB/HSIC, character device and more
** {USB,CALLBACK,MEMORY_DEVICE,UART,NO_LOGGING}_MODE
driver/schar/diag/diag_dci.c
* DCI table is a routing table where pid/sockets can register for a
given DCI. socket close/cleanup code releases all DCI routes for
that socket.
h2. SMD (shared memory)
* SMD sub-systems:
** Modem (assumed to be hexagon with modem firmware?)
** Q6 (formerly known as LPASS == Low Power Audio SubSystem)
** DSPS
** WCNSS (Wireless Connectivity Sub System) aka 'riva'
** RPM (Resource Power Manager)
* inter-processor-interrupts for various 'edges'
h3. core driver
* arch/arm/mach-msm/smd.c
h4. api
* smd_open()
* smd_close()
* smd_write*()
* smd_read*()
* smsm_*()
h3. MSM IPC socket
* arch/arm/mach-msm/ipc_socket.c
* AF_MSM_IPC
h3. packet ports
* Some kind of packet oriented interface towards the SMD
* msm_smd_pkt.c contains driver
** smdpkt0..7+smd22 devices, 2048 byte buffer
** open/release/read/write/poll syscalls implemented
