bsps/aarch64/raspberrypi: Add system timer support

The clock from the ARM timer is derived from the system clock. This clock can
change dynamically e.g. if the system goes into reduced power or in low power
mode. Thus the clock speed adapts to the overall system performance
capabilities. For accurate timing it is recommended to use the system timers.

if BSP_CLOCK_USE_SYSTEMTIMER = 1, use the System Timer, otherwise use the ARM
Timer.

spec/build/bsps/aarch64/grp.yml

@@ -12,9 +12,6 @@ install:
   source:
   - bsps/aarch64/include/bsp/linker-symbols.h
   - bsps/aarch64/include/bsp/start.h
-- destination: ${BSP_INCLUDEDIR}/dev/clock
-  source:
-  - bsps/include/dev/clock/arm-generic-timer.h
 - destination: ${BSP_INCLUDEDIR}/dev/irq
   source:
   - bsps/aarch64/include/dev/irq/arm-gic-arch.h

spec/build/bsps/aarch64/raspberrypi/bspraspberrypi4.yml

@@ -19,6 +19,10 @@ install:
   - bsps/aarch64/raspberrypi/include/bsp/irq.h
   - bsps/aarch64/raspberrypi/include/bsp/raspberrypi.h
 links:
+- role: build-dependency
+  uid: objclock
+- role: build-dependency
+  uid: objsystemtimer
 - role: build-dependency
   uid: ../grp
 - role: build-dependency
@@ -50,10 +54,8 @@ source:
 - bsps/aarch64/raspberrypi/start/bspstart.c
 - bsps/aarch64/raspberrypi/start/bspstarthooks.c
 - bsps/aarch64/raspberrypi/start/bspstartmmu.c
-- bsps/aarch64/shared/clock/arm-generic-timer-aarch64.c
 - bsps/aarch64/shared/cache/cache.c
 - bsps/aarch64/shared/mmu/vmsav8-64.c
-- bsps/shared/dev/clock/arm-generic-timer.c
 - bsps/shared/dev/irq/arm-gicv2.c
 - bsps/shared/dev/irq/arm-gicv2-get-attributes.c
 - bsps/shared/dev/serial/console-termios-init.c

spec/build/bsps/aarch64/raspberrypi/objclock.yml

@@ -0,0 +1,31 @@
+SPDX-License-Identifier: CC-BY-SA-4.0 OR BSD-2-Clause
+copyrights:
+  - Copyright (C) 2022 Mohd Noor Aman
+  - Copyright (C) 2023 Utkarsh Verma
+  - Copyright (C) 2024 Ning Yang
+
+type: build
+enabled-by:
+  not: BSP_CLOCK_USE_SYSTEMTIMER
+
+build-type: objects
+cflags: []
+cppflags: []
+cxxflags: []
+includes: []
+install:
+- destination: ${BSP_INCLUDEDIR}/dev/clock
+  source:
+  - bsps/include/dev/clock/arm-generic-timer.h
+
+source:
+  - bsps/aarch64/shared/clock/arm-generic-timer-aarch64.c
+  - bsps/shared/dev/clock/arm-generic-timer.c
+
+links:
+  - role: build-dependency
+    uid: ../optgtusevirt
+  - role: build-dependency
+    uid: ../optgtuseps
+  - role: build-dependency
+    uid: optsystemtimer

spec/build/bsps/aarch64/raspberrypi/objsystemtimer.yml

@@ -0,0 +1,23 @@
+SPDX-License-Identifier: CC-BY-SA-4.0 OR BSD-2-Clause
+copyrights:
+  - Copyright (C) 2024 Ning Yang
+
+type: build
+enabled-by:
+- BSP_CLOCK_USE_SYSTEMTIMER
+
+build-type: objects
+cflags: []
+cppflags: []
+cxxflags: []
+includes: []
+install: []
+
+source:
+  - bsps/shared/dev/clock/bcm2835-system-timer.c
+  - bsps/shared/dev/cpucounter/cpucounterfrequency.c
+  - bsps/shared/dev/cpucounter/cpucounterread.c
+
+links:
+  - role: build-dependency
+    uid: optsystemtimer

spec/build/bsps/aarch64/raspberrypi/optsystemtimer.yml

@@ -0,0 +1,25 @@
+SPDX-License-Identifier: CC-BY-SA-4.0 OR BSD-2-Clause
+copyrights:
+  - Copyright (C) 2024 Ning Yang
+
+type: build
+build-type: option
+
+enabled-by: true
+name: BSP_CLOCK_USE_SYSTEMTIMER
+description: |
+  The clock from the ARM timer is derived from the system clock. This clock can
+  change dynamically e.g. if the system goes into reduced power or in low power
+  mode. Thus the clock speed adapts to the overall system performance
+  capabilities. For accurate timing it is recommended to use the system timers.
+
+actions:
+  - get-boolean: null
+  - define-condition: null
+  - env-enable: null
+default:
+  - enabled-by:
+    - aarch64/raspberrypi4b
+    value: false
+
+links: []