vexpress64: Add ARMv8R-64 board variant

The ARMv8-R64 architecture introduces optional VMSA (paging based MMU)
support in the EL1/0 translation regime, which makes that part mostly
compatible to ARMv8-A.

Add a new board variant to describe the "BASE-R64" FVP model, which
inherits a lot from the existing v8-A FVP support. One major difference
is that the memory map in "inverted": DRAM starts at 0x0, MMIO is at
2GB [1].

 * Create new TARGET_VEXPRESS64_BASER_FVP target, sharing most of the
   exising configuration.
 * Implement inverted memory map in vexpress_aemv8.h
 * Create vexpress_aemv8r defconfig
 * Provide an MMU memory map for the BASER_FVP
 * Update vexpress64 documentation

At the moment the boot-wrapper is the only supported secure firmware. As
there is no official DT for the board yet, we rely on it being supplied
by the boot-wrapper into U-Boot, so use OF_HAS_PRIOR_STAGE, and go with
a dummy DT for now.

[1] https://developer.arm.com/documentation/100964/1114/Base-Platform/Base---memory/BaseR-Platform-memory-map

Signed-off-by: Peter Hoyes <Peter.Hoyes@arm.com>
[Andre: rebase and add Linux kernel header]
Signed-off-by: Andre Przywara <andre.przywara@arm.com>
[trini: Add MAINTAINERS entry for Peter]

arch/arm/dts/Makefile

@@ -1186,6 +1186,7 @@ dtb-$(CONFIG_TARGET_MX53PPD) += imx53-ppd.dtb
 # Kconfig option to build all of these. See examples above.
 dtb-$(CONFIG_TARGET_VEXPRESS_CA9X4) += vexpress-v2p-ca9.dtb
 dtb-$(CONFIG_TARGET_VEXPRESS64_BASE_FVP) += fvp-base-revc.dtb
+dtb-$(CONFIG_TARGET_VEXPRESS64_BASER_FVP) += arm_fvp.dtb
 dtb-$(CONFIG_TARGET_VEXPRESS64_JUNO) += juno-r2.dtb
 
 dtb-$(CONFIG_TARGET_TOTAL_COMPUTE) += total_compute.dtb

arch/arm/dts/arm_fvp.dts

@@ -0,0 +1,11 @@
+// SPDX-License-Identifier: GPL-2.0+ OR MIT
+/*
+ * Empty device tree for the Arm Ltd FVP platform model
+
+ * Copyright 2022 Arm Ltd.
+ */
+
+/dts-v1/;
+
+/ {
+};

board/armltd/vexpress64/Kconfig

@@ -9,19 +9,28 @@ config SYS_VENDOR
 config SYS_CONFIG_NAME
 	default "vexpress_aemv8"
 
-choice
+config VEXPRESS64_BASE_MODEL
-	prompt "VExpress64 board variant"
+	bool
-
-config TARGET_VEXPRESS64_BASE_FVP
-	bool "Support Versatile Express ARMv8a FVP BASE model"
 	select SEMIHOSTING
 	select VIRTIO_BLK if VIRTIO_MMIO
 	select VIRTIO_NET if VIRTIO_MMIO
 	select DM_ETH if VIRTIO_NET
 	select LINUX_KERNEL_IMAGE_HEADER
 	select POSITION_INDEPENDENT
+
+choice
+	prompt "VExpress64 board variant"
+
+config TARGET_VEXPRESS64_BASE_FVP
+	bool "Support Versatile Express ARMv8a FVP BASE model"
+	select VEXPRESS64_BASE_MODEL
 	select OF_BOARD
 
+config TARGET_VEXPRESS64_BASER_FVP
+	bool "Support Versatile Express ARMv8r64 FVP BASE model"
+	select VEXPRESS64_BASE_MODEL
+	imply OF_HAS_PRIOR_STAGE
+
 config TARGET_VEXPRESS64_JUNO
 	bool "Support Versatile Express Juno Development Platform"
 	select PCIE_ECAM_GENERIC if PCI
@@ -50,6 +59,7 @@ config LNX_KRNL_IMG_TEXT_OFFSET_BASE
 config SYS_TEXT_BASE
 	default 0x88000000 if TARGET_VEXPRESS64_BASE_FVP
 	default 0xe0000000 if TARGET_VEXPRESS64_JUNO
+	default 0x00001000 if TARGET_VEXPRESS64_BASER_FVP
 
 config SYS_MALLOC_LEN
 	default 0x810000 if TARGET_VEXPRESS64_JUNO
@@ -59,11 +69,13 @@ config SYS_MALLOC_F_LEN
 	default 0x2000
 
 config SYS_LOAD_ADDR
+	default 0x10000000 if TARGET_VEXPRESS64_BASER_FVP
 	default 0x90000000
 
 config ENV_ADDR
 	default 0x0BFC0000 if TARGET_VEXPRESS64_JUNO
 	default 0x0FFC0000 if TARGET_VEXPRESS64_BASE_FVP
+	default 0x8FFC0000 if TARGET_VEXPRESS64_BASER_FVP
 
 config ENV_SIZE
 	default 0x10000 if TARGET_VEXPRESS64_JUNO

board/armltd/vexpress64/MAINTAINERS

@@ -14,3 +14,8 @@ JUNO DEVELOPMENT PLATFORM BOARD
 M:	Linus Walleij <linus.walleij@linaro.org>
 S:	Maintained
 F:	configs/vexpress_aemv8a_juno_defconfig
+
+VEXPRESS64 ARMV8R-64
+M:	Peter Hoyes <Peter.Hoyes@arm.com>
+S:	Maintained
+F:	configs/vexpress_aemv8r_defconfig

configs/vexpress_aemv8r_defconfig

@@ -0,0 +1,14 @@
+CONFIG_ARM=y
+CONFIG_ARCH_VEXPRESS64=y
+CONFIG_NR_DRAM_BANKS=2
+CONFIG_DEFAULT_DEVICE_TREE="arm_fvp"
+CONFIG_IDENT_STRING=" vexpress_aemv8r64"
+CONFIG_TARGET_VEXPRESS64_BASER_FVP=y
+CONFIG_REMAKE_ELF=y
+CONFIG_BOOTDELAY=3
+CONFIG_USE_BOOTARGS=y
+CONFIG_BOOTARGS="console=ttyAMA0 earlycon=pl011,0x9c090000 rootfstype=ext4 root=/dev/vda2 rw rootwait"
+# CONFIG_DISPLAY_CPUINFO is not set
+CONFIG_SYS_PROMPT="VExpress64# "
+# CONFIG_MMC is not set
+CONFIG_VIRTIO_MMIO=y

doc/arch/arm64.rst

@@ -18,7 +18,8 @@ Notes
    classical firmware (like initial hardware setup, CPU errata workarounds
    or SMP bringup). U-Boot can be entered in EL2 when its main purpose is
    that of a boot loader. It can drop to lower exception levels before
-   entering the OS.
+   entering the OS. For ARMv8-R it is recommened to enter at S-EL1, as for this
+   architecture there is no S-EL3.
 
 2. U-Boot for arm64 is compiled with AArch64-gcc. AArch64-gcc
    use rela relocation format, a tool(tools/relocate-rela) by Scott Wood

doc/board/armltd/vexpress64.rst

@@ -6,6 +6,7 @@ Arm Versatile Express
 The vexpress_* board configuration supports the following platforms:
 
  * FVP_Base_RevC-2xAEMvA
+ * FVP_BaseR_AEMv8R
  * Juno development board
 
 Fixed Virtual Platforms

include/configs/vexpress_aemv8.h

@@ -20,8 +20,13 @@
 #define CONFIG_SYS_BOOTM_LEN (64 << 20)      /* Increase max gunzip size */
 
 /* CS register bases for the original memory map. */
+#ifdef CONFIG_TARGET_VEXPRESS64_BASER_FVP
+#define V2M_DRAM_BASE			0x00000000
+#define V2M_PA_BASE			0x80000000
+#else
 #define V2M_DRAM_BASE			0x80000000
 #define V2M_PA_BASE			0x00000000
+#endif
 
 #define V2M_PA_CS0			(V2M_PA_BASE + 0x00000000)
 #define V2M_PA_CS1			(V2M_PA_BASE + 0x14000000)
@@ -229,6 +234,24 @@
 		"boot_name=boot.img\0"					\
 		"boot_addr_r=" __stringify(VEXPRESS_BOOT_ADDR) "\0"
 
+#elif CONFIG_TARGET_VEXPRESS64_BASER_FVP		/* ARMv8-R base model */
+
+#define BOOT_TARGET_DEVICES(func)	\
+	func(MEM, mem, na)		\
+	FUNC_VIRTIO(func)		\
+	func(PXE, pxe, na)		\
+	func(DHCP, dhcp, na)
+
+#define VEXPRESS_KERNEL_ADDR		0x00200000
+#define VEXPRESS_PXEFILE_ADDR		0x0fb00000
+#define VEXPRESS_FDT_ADDR		0x0fc00000
+#define VEXPRESS_SCRIPT_ADDR		0x0fd00000
+#define VEXPRESS_RAMDISK_ADDR		0x0fe00000
+
+#define EXTRA_ENV_NAMES							\
+					"kernel_name=Image\0"		\
+					"ramdisk_name=ramdisk.img\0"	\
+					"fdtfile=board.dtb\0"
 #endif
 
 #include <config_distro_bootcmd.h>