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Diffstat (limited to 'docs/porting-guide.md')
| -rw-r--r-- | docs/porting-guide.md | 13 |
1 files changed, 8 insertions, 5 deletions
diff --git a/docs/porting-guide.md b/docs/porting-guide.md index 6bba3604..5dca6fd5 100644 --- a/docs/porting-guide.md +++ b/docs/porting-guide.md @@ -208,6 +208,13 @@ the implementer chooses. In the ARM FVP port, they are implemented in platform) & `platform_get_stack()` (to return the base address of that stack) (see [../plat/common/aarch64/platform_helpers.S]). +* **Function : uint64_t plat_get_syscnt_freq(void)** + + This function is used by the architecture setup code to retrieve the + counter frequency for the CPU's generic timer. This value will be + programmed into the `CNTFRQ_EL0` register. + In the ARM FVP port, it returns the base frequency of the system counter, + which is retrieved from the first entry in the frequency modes table. 2.2 Common optional modifications --------------------------------- @@ -446,10 +453,6 @@ This function executes with the MMU and data caches enabled. It is responsible for performing any remaining platform-specific setup that can occur after the MMU and data cache have been enabled. -In the ARM FVP port, this function enables system-level implementation of the -generic timer counter. It also initializes counter frequency for CPU's generic -timers. - This function is also responsible for initializing the storage abstraction layer which is used to load further bootloader images. @@ -772,7 +775,7 @@ BL3-1 runtime services and normal world software can function correctly. The ARM FVP port does the following: * Initializes the generic interrupt controller. * Configures the CLCD controller. -* Initializes counter frequency for CPU's generic timer +* Enables system-level implementation of the generic timer counter. * Grants access to the system counter timer module * Initializes the FVP power controller device * Detects the system topology. |