linux-arkmicro/buildroot-external/package/hx280enc/software/linux_reference/ewl

Hantro 6280/7280/8270/8290 Encoder Wrapper Layer

Three implementations of the EWL exist:
- ewl_x280_file.c
+ A stand-alone user-space implementation, no HW, input from file
+ Used for software testing and simulations
- ewl_x280_polling.c ewl_x280_common.c ewl_linux_lock.c
+ A user-space implementation, polling used instead of interrupts
+ Requires the kernel driver just for getting the HW IO base
- ewl_x280_irq.c ewl_x280_common.c ewl_linux_lock.c
+ EWL for Linux that requires a kernel driver to handle the interrupts
+ Kernel driver implemented for Linux kernel 2.6

NOTES:
- ewl_x280_common.c contains common parts for linux
- ewl_linux_lock.c contains the linux binary semaphore handling for
multi-instance



The kernel driver is built separately from the codec library and loaded into
the kernel. The user space interface is compiled into the codec library.
These two communicate using signals and standard device I/O.

Compile time parameters:

EWL_NO_HW_TIMEOUT - EWL does not support timed wait. Always define!
SDRAM_LM_BASE=n - base address of the RAM as seen by HW
(0x80000000 in Integrator and 0x00 in Versatile)
ENC_IO_BASE=n - base address of the HW IO registers
ENC_MODULE_PATH=n - path of the encoder device file used to communicate with the
kernel driver