SHx Kernels (Windows CE 5.0)
Before control is transferred to the kernel, the boot loader passes control to the StartUp routine to put the CPU into as initialized state.
The following table shows the SHx-based BSP and source file locations included in Platform Builder for which the StartUp function is specified.
| BSP | Source file |
|---|---|
| Renesas US7750R HARP (Aspen) - SH4 | %_WINCEROOT%\Platform\Aspen\Kernel\Hal\SH |
OEMs developing for the SHx processor using the SHx kernel are expected to perform the following tasks:
- Set up bus state control registers
- Set up frequency control registers
- Disable cache
- Initialize watchdog timer
When the FRQ Control Register is modified it creates instability in the PLL. For this reason, when FRQCR is modified, the CPU shuts off. The watchdog timer can be programmed to cause a system wakeup with an interval of 0.
Until the bus controller has been initialized, some of debug devices, such as discrete LEDs and timing loops, may not be correct. BCR1 sets the types of memory that are being used. BCR2 is used to set the bus widths of all of the memory areas.
See Also
CPU Initialization | OAL StartUp Function Implementation
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