From b60c2519d7bac1d70379f0b437ae5f2aa36eece6 Mon Sep 17 00:00:00 2001 From: Gregory Nutt Date: Fri, 20 Nov 2015 07:13:16 -0600 Subject: [PATCH] arch.h: Update some comments and conditional compilation --- include/nuttx/arch.h | 12 +++++++++--- 1 file changed, 9 insertions(+), 3 deletions(-) diff --git a/include/nuttx/arch.h b/include/nuttx/arch.h index 4c070a7d1a..0c79bd292c 100644 --- a/include/nuttx/arch.h +++ b/include/nuttx/arch.h @@ -1768,8 +1768,14 @@ size_t up_check_intstack_remain(void); * Name: up_rtcinitialize * * Description: - * Initialize the hardware RTC per the selected configuration. This - * function is called once during the OS initialization sequence + * Initialize the builtin, MCU hardware RTC per the selected + * configuration. This function is called once very early in the OS + * initialization sequence + * + * NOTE that initialization of external RTC hardware that depends on the + * availability of OS resources (such as SPI or I2C) must be deferred + * until the system has fully booted. Other, RTC-specific initialization + * functions are used in that case. * * Input Parameters: * None @@ -1779,7 +1785,7 @@ size_t up_check_intstack_remain(void); * ****************************************************************************/ -#ifdef CONFIG_RTC +#if defined(CONFIG_RTC) && !defined(CONFIG_RTC_EXTERNAL) int up_rtcinitialize(void); #endif