From 21258e2674226d6aa732321b6f8494841895af5f Mon Sep 17 00:00:00 2001
From: Alexander von Gluck IV <kallisti5@unixzen.com>
Date: Wed, 19 Aug 2020 10:03:24 -0500
Subject: [PATCH] riscv64: Fill in some missing CPU defines, advance build
 further
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Change-Id: Id050fad59ede444f2eab7eca681c6ec44612aaf9
Reviewed-on: https://review.haiku-os.org/c/haiku/+/3160
Reviewed-by: Alex von Gluck IV <kallisti5@unixzen.com>
Reviewed-by: François Revol <revol@free.fr>
---
 .../kernel/boot/arch/riscv64/arch_cpu.h       | 25 +++++++
 src/system/boot/Jamfile                       |  2 +
 src/system/boot/arch/riscv64/Jamfile          |  2 +
 src/system/boot/arch/riscv64/arch_cpu.cpp     | 73 +++++++++++++++++++
 src/system/kernel/arch/riscv64/arch_debug.cpp | 10 ++-
 5 files changed, 110 insertions(+), 2 deletions(-)
 create mode 100644 headers/private/kernel/boot/arch/riscv64/arch_cpu.h
 create mode 100644 src/system/boot/arch/riscv64/arch_cpu.cpp

diff --git a/headers/private/kernel/boot/arch/riscv64/arch_cpu.h b/headers/private/kernel/boot/arch/riscv64/arch_cpu.h
new file mode 100644
index 0000000000..0bb2f6ec5c
--- /dev/null
+++ b/headers/private/kernel/boot/arch/riscv64/arch_cpu.h
@@ -0,0 +1,25 @@
+/*
+ * Copyright 2013-2020 Haiku, Inc. All rights reserved.
+ * Distributed under the terms of the MIT License.
+ */
+#ifndef BOOT_ARCH_CPU_H
+#define BOOT_ARCH_CPU_H
+
+
+#include <SupportDefs.h>
+#include <boot/vfs.h>
+
+
+#ifdef __cplusplus
+extern "C" {
+#endif
+
+status_t boot_arch_cpu_init(void);
+void arch_ucode_load(BootVolume& volume);
+
+#ifdef __cplusplus
+}
+#endif
+
+
+#endif /* BOOT_ARCH_CPU_H */
diff --git a/src/system/boot/Jamfile b/src/system/boot/Jamfile
index 6a1f525502..f0bd545b83 100644
--- a/src/system/boot/Jamfile
+++ b/src/system/boot/Jamfile
@@ -113,6 +113,8 @@ rule BuildEFILoader {
 			OUTPUT_TARGET on $(efiLoader) = binary ;
 		case arm64 :
 			OUTPUT_TARGET on $(efiLoader) = binary ;
+		case riscv64 :
+			OUTPUT_TARGET on $(efiLoader) = binary ;
 		case * :
 			Exit "Currently unsupported arch:" $(TARGET_ARCH) ;
 	}
diff --git a/src/system/boot/arch/riscv64/Jamfile b/src/system/boot/arch/riscv64/Jamfile
index 1d074a78d8..c8dd186300 100644
--- a/src/system/boot/arch/riscv64/Jamfile
+++ b/src/system/boot/arch/riscv64/Jamfile
@@ -22,6 +22,8 @@ local kernelDebugSources =
 
 local kernelArchDriverSources =
 	arch_elf.cpp
+	arch_cpu.cpp
+
 	# Serial UART Drivers
 	#arch_uart_8250.cpp
 	#arch_uart_8250_omap.cpp
diff --git a/src/system/boot/arch/riscv64/arch_cpu.cpp b/src/system/boot/arch/riscv64/arch_cpu.cpp
new file mode 100644
index 0000000000..0b1ace2b85
--- /dev/null
+++ b/src/system/boot/arch/riscv64/arch_cpu.cpp
@@ -0,0 +1,73 @@
+/*
+ * Copyright 2012-2020, Haiku, Inc. All rights reserved.
+ * Distributed under the terms of the MIT License.
+ *
+ * Authors:
+ *		Ithamar R. Adema <ithamar@upgrade-android.com>
+ */
+
+#include <OS.h>
+#include <boot/platform.h>
+#include <boot/stdio.h>
+#include <boot/kernel_args.h>
+#include <boot/stage2.h>
+#include <arch/cpu.h>
+#include <arch_kernel.h>
+#include <arch_system_info.h>
+#include <string.h>
+
+
+#define TRACE_CPU
+#ifdef TRACE_CPU
+#	define TRACE(x) dprintf x
+#else
+#	define TRACE(x) ;
+#endif
+
+
+/*! Detect RISCV core extensions.
+*/
+static status_t
+check_cpu_features()
+{
+	// only seems possible from bootloader openfirmware or FDT?
+	return B_OK;
+}
+
+
+extern "C" status_t
+boot_arch_cpu_init(void)
+{
+	status_t err = check_cpu_features();
+	if (err != B_OK) {
+		panic("It's RISCY business trying to boot Haiku on the wrong CPU!\n");
+		return err;
+	}
+
+	return B_OK;
+}
+
+
+extern "C" void
+arch_ucode_load(BootVolume& volume)
+{
+	// NOP on riscv currently
+}
+
+
+extern "C" bigtime_t
+system_time()
+{
+	#warning Implement system_time in RISCV bootloader!
+	return 0;
+}
+
+
+extern "C" void
+spin(bigtime_t microseconds)
+{
+	#warning Implment spin in RISCV bootloader!
+	//bigtime_t time = system_time();
+	//while ((system_time() - time) < microseconds)
+	//	asm volatile ("nop;");
+}
diff --git a/src/system/kernel/arch/riscv64/arch_debug.cpp b/src/system/kernel/arch/riscv64/arch_debug.cpp
index 495c9abf0e..07a48ef0da 100644
--- a/src/system/kernel/arch/riscv64/arch_debug.cpp
+++ b/src/system/kernel/arch/riscv64/arch_debug.cpp
@@ -1,5 +1,5 @@
 /*
- * Copyright 2019, Haiku, Inc. All rights reserved.
+ * Copyright 2019-2020, Haiku, Inc. All rights reserved.
  * Distributed under the terms of the MIT License.
  *
  * Authors:
@@ -92,6 +92,13 @@ arch_debug_get_interrupt_pc(bool* _isSyscall)
 }
 
 
+void
+arch_debug_unset_current_thread(void)
+{
+	// TODO: Implement!
+}
+
+
 status_t
 arch_debug_init(kernel_args *args)
 {
@@ -103,4 +110,3 @@ arch_debug_init(kernel_args *args)
 
 	return B_NO_ERROR;
 }
-