soc: arm: xilinx_zynqmp: Refactor for multi-arch support.

The Xilinx ZynqMP SoC embeds both Cortex-R "RPU" and Cortex-A "APU"
cores.

Since the current Zephyr architecture cannot support AMP of Cortex-R
and Cortex-A within the same project, the RPU and APU should be
considered separate platforms and handled accordingly.

This commit re-purposes the SOC_XILINX_ZYNQMP symbol as a helper symbol
indicating that Xilinx ZynqMP SoC is used, and adds a new symbol,
SOC_XILINX_ZYNQMP_RPU, for specifying the actual build target platform.

When Cortex-A support is added in the future, SOC_XILINX_ZYNQMP_APU
symbol should be added and used to conditionally handle APU-specific
code.

For more details, refer to the issue zephyrproject-rtos#20217.

Signed-off-by: Stephanos Ioannidis <root@stephanos.io>

boards/arm/qemu_cortex_r5/Kconfig.board

@@ -3,4 +3,4 @@
 
 config BOARD_QEMU_CORTEX_R5
 	bool "Cortex-R5 Emulation (QEMU)"
-	depends on SOC_XILINX_ZYNQMP
+	depends on SOC_XILINX_ZYNQMP_RPU

boards/arm/qemu_cortex_r5/qemu_cortex_r5_defconfig

@@ -1,5 +1,5 @@
 CONFIG_ARM=y
-CONFIG_SOC_XILINX_ZYNQMP=y
+CONFIG_SOC_XILINX_ZYNQMP_RPU=y
 CONFIG_BOARD_QEMU_CORTEX_R5=y
 CONFIG_XIP=n
 

soc/arm/xilinx_zynqmp/Kconfig

@@ -0,0 +1,5 @@
+# Copyright (c) 2019 Stephanos Ioannidis <root@stephanos.io>
+# SPDX-License-Identifier: Apache-2.0
+
+config SOC_XILINX_ZYNQMP
+	bool

soc/arm/xilinx_zynqmp/Kconfig.defconfig

@@ -1,11 +1,14 @@
 # Copyright (c) 2019 Lexmark International, Inc.
+# Copyright (c) 2019 Stephanos Ioannidis <root@stephanos.io>
 # SPDX-License-Identifier: Apache-2.0
 
 if SOC_XILINX_ZYNQMP
 
 config SOC
 	default "xilinx_zynqmp"
 
+if SOC_XILINX_ZYNQMP_RPU
+
 config NUM_IRQS
 	# must be >= the highest interrupt number used
 	# - include the UART interrupts
@@ -23,6 +26,8 @@ config NUM_2ND_LEVEL_AGGREGATORS
 config SYS_CLOCK_HW_CYCLES_PER_SEC
 	default 12000000
 
+endif # SOC_XILINX_ZYNQMP_RPU
+
 # Workaround for not being able to have commas in macro arguments
 DT_CHOSEN_Z_FLASH := zephyr,flash
 
@@ -32,4 +37,4 @@ config FLASH_SIZE
 config FLASH_BASE_ADDRESS
 	default $(dt_chosen_reg_addr_hex,$(DT_CHOSEN_Z_FLASH))
 
-endif
+endif # SOC_XILINX_ZYNQMP

soc/arm/xilinx_zynqmp/Kconfig.soc

@@ -1,9 +1,11 @@
 # Copyright (c) 2019 Lexmark International, Inc.
+# Copyright (c) 2019 Stephanos Ioannidis <root@stephanos.io>
 # SPDX-License-Identifier: Apache-2.0
 
-config SOC_XILINX_ZYNQMP
-	bool "Xilinx ZynqMP"
+config SOC_XILINX_ZYNQMP_RPU
+	bool "Xilinx ZynqMP RPU"
 	select CPU_CORTEX_R5
+	select SOC_XILINX_ZYNQMP
 	select GIC_V1
 	select MULTI_LEVEL_INTERRUPTS
 	select 2ND_LEVEL_INTERRUPTS

soc/arm/xilinx_zynqmp/linker.ld

@@ -1,8 +1,12 @@
 /*
  * Copyright (c) 2019 Lexmark International, Inc.
+ * Copyright (c) 2019 Stephanos Ioannidis <root@stephanos.io>
  *
  * SPDX-License-Identifier: Apache-2.0
- *
  */
 
+#include <autoconf.h>
+
+#if defined(CONFIG_SOC_XILINX_ZYNQMP_RPU)
 #include <arch/arm/aarch32/cortex_r/scripts/linker.ld>
+#endif