build: Add riscv architecture

* I mean, qemu 3.0 supports it.
* Nobody get excited, we need all the triplets added to
  our gcc buildtools. clang 7.0 seems to be cool with riscv though.

Change-Id: I17728163e4f28a3c16cee482a253364724b06f3a

build/jam/ArchitectureRules

@@ -295,6 +295,32 @@ rule KernelArchitectureSetup architecture
 				Exit "HAIKU_NASM not set. Please re-run configure." ;
 			}
 
+		case riscv32 :
+			HAIKU_BOOT_PLATFORM ?= u-boot ;
+			HAIKU_BOOT_TARGETS += u-boot ;
+
+			HAIKU_BOOT_SDIMAGE_SIZE ?= 128 ;
+			# SOC's like allwinner need an offset to skip the hardcoded initial loader
+			HAIKU_BOOT_SDIMAGE_BEGIN = 40950 ; # 512-byte sectors (divisible by 63)
+
+			HAIKU_BOOT_FLOPPY_IMAGE_SIZE = 1440 ;
+			# offset in floppy image (>= sizeof(haiku_loader))
+			HAIKU_BOOT_ARCHIVE_IMAGE_OFFSET = 192 ; # in kB - unused yet
+			HAIKU_BOOT_LOADER_BASE ?= 0x1000000 ;
+
+		case riscv64 :
+			HAIKU_BOOT_PLATFORM ?= u-boot ;
+			HAIKU_BOOT_TARGETS += u-boot ;
+
+			HAIKU_BOOT_SDIMAGE_SIZE ?= 128 ;
+			# SOC's like allwinner need an offset to skip the hardcoded initial loader
+			HAIKU_BOOT_SDIMAGE_BEGIN = 40950 ; # 512-byte sectors (divisible by 63)
+
+			HAIKU_BOOT_FLOPPY_IMAGE_SIZE = 1440 ;
+			# offset in floppy image (>= sizeof(haiku_loader))
+			HAIKU_BOOT_ARCHIVE_IMAGE_OFFSET = 192 ; # in kB - unused yet
+			HAIKU_BOOT_LOADER_BASE ?= 0x1000000 ;
+
 		case x86_64 :
 			# x86_64 completely shares the x86 bootloader for MBR.
 			HAIKU_KERNEL_PLATFORM ?= bios_ia32 ;

configure

@@ -32,7 +32,8 @@ options:
                               directory under "cross-tools". The HAIKU_* tools
                               variables will be set accordingly.
                               <arch> specifies the target architecture, either
-                              "x86_gcc2", "x86", "x86_64", "ppc", "m68k", "arm", "arm64"
+                              "x86_gcc2", "x86", "x86_64", "ppc", "m68k",
+                              "arm", "arm64", "riscv32", "riscv64"
                               This option and --cross-tools-prefix can be
                               specified multiple times. The first cross tools
                               specify the primary tools, the subsequent ones the
@@ -270,6 +271,8 @@ standard_gcc_settings()
 		i?86-*)		targetCpu=x86;;
 		m68k-*)		targetCpu=m68k;;
 		powerpc-*)	targetCpu=ppc;;
+		riscv32-*)	targetCpu=riscv32;;
+		riscv64-*)	targetCpu=riscv64;;
 		x86_64-*)	targetCpu=x86_64;;
 		*)
 			echo "Unsupported gcc target machine: $gccMachine" >&2
@@ -627,6 +630,8 @@ supportedTargetArchs="
 	arm64
 	m68k
 	ppc
+	riscv32
+	riscv64
 	x86
 	x86_64
 	x86_gcc2
@@ -675,6 +680,8 @@ while [ $# -gt 0 ] ; do
 				ppc)		targetMachine=powerpc-apple-haiku;;
 				m68k)		targetMachine=m68k-unknown-haiku;;
 				arm)		targetMachine=arm-unknown-haiku;;
+				riscv32)	targetMachine=riscv32-unknown-haiku;;
+				riscv64)	targetMachine=riscv64-unknown-haiku;;
 				*)
 					echo "Unsupported target architecture: $targetArch" >&2
 					exit 1
@@ -733,6 +740,8 @@ while [ $# -gt 0 ] ; do
 				ppc)		targetMachine=powerpc-apple-haiku;;
 				arm)		targetMachine=arm-unknown-haiku;;
 				arm64)		targetMachine=arm64-unknown-haiku;;
+				riscv32)	targetMachine=riscv32-unknown-haiku;;
+				riscv64)	targetMachine=riscv64-unknown-haiku;;
 				*)
 					echo "Unsupported target architecture: $2" >&2
 					exit 1

headers/config/HaikuConfig.h

@@ -61,6 +61,16 @@
 #	define __HAIKU_ARCH_ABI				"arm64"
 #	define __HAIKU_ARCH_ARM64			1
 #	define __HAIKU_ARCH_BITS			64
+#elif defined(__riscv32__) || (defined(__riscv) && __riscv_xlen == 32)
+#	define __HAIKU_ARCH					riscv32
+#	define __HAIKU_ARCH_ABI				"riscv32"
+#	define __HAIKU_ARCH_RISCV32			1
+#	define __HAIKU_ARCH_BITS			32
+#elif defined(__riscv64__) || (defined(__riscv) && __riscv_xlen == 64)
+#	define __HAIKU_ARCH					riscv64
+#	define __HAIKU_ARCH_ABI				"riscv64"
+#	define __HAIKU_ARCH_RISCV32			1
+#	define __HAIKU_ARCH_BITS			64
 #else
 #	error Unsupported architecture!
 #endif