diff options
Diffstat (limited to 'cpukit/score/cpu/arm/include/rtems/score/paravirt.h')
-rw-r--r-- | cpukit/score/cpu/arm/include/rtems/score/paravirt.h | 75 |
1 files changed, 75 insertions, 0 deletions
diff --git a/cpukit/score/cpu/arm/include/rtems/score/paravirt.h b/cpukit/score/cpu/arm/include/rtems/score/paravirt.h new file mode 100644 index 0000000000..08fb8a08ef --- /dev/null +++ b/cpukit/score/cpu/arm/include/rtems/score/paravirt.h @@ -0,0 +1,75 @@ +/** + * @file + * + * @brief ARM Paravirtualization Definitions + * + * This include file contains definitions pertaining to paravirtualization + * of the ARM port. + */ + +/* + * COPYRIGHT (c) 2018. + * On-Line Applications Research Corporation (OAR). + * + * The license and distribution terms for this file may in + * the file LICENSE in this distribution or at + * http://www.rtems.org/license/LICENSE. + */ + + +#ifndef RTEMS_PARAVIRT +#error "This file should only be included with paravirtualization is enabled." +#endif + +#ifndef _RTEMS_SCORE_PARAVIRT_H +#define _RTEMS_SCORE_PARAVIRT_H + +/** + * @defgroup ParavirtARM Paravirtualization ARM Support + * + * @ingroup Score + * + * This handler encapulates the functionality (primarily conditional + * feature defines) related to paravirtualization on the ARM. + * + * Paravirtualization on the ARM makes the following assumptions: + * + * - RTEMS executes in user space + * - Interrupt enable/disable support using the MSR must be disabled + * and replaced with BSP provided methods which are adapted to the + * hosting environment. + */ + +#ifndef ASM + +#ifdef __cplusplus +extern "C" { +#endif + +#ifdef __cplusplus +} +#endif + +#endif /* !ASM */ + +/** + * In a paravirtualized environment, RTEMS executes in user space + * and cannot disable/enable external exceptions (e.g. interrupts). + * The BSP which acts as an adapter to the hosting environment will + * provide the interrupt enable/disable methods. + */ +#define ARM_DISABLE_INLINE_ISR_DISABLE_ENABLE + +/** + * In a paravirtualized environment, RTEMS executes in user space + * and cannot write to the the Thread ID register which is normally + * used. CP15 C13 has three variants of a Thread ID register. + * + * - Opcode_2 = 2: This register is both user and privileged R/W accessible. + * - Opcode_2 = 3: This register is user read-only and privileged + * R/W accessible. + * - Opcode_2 = 4: This register is privileged R/W accessible only. + */ +#define ARM_DISABLE_THREAD_ID_REGISTER_USE + +#endif |