U-Boot: split cpu.cpp into arch-specific and common parts

* the common part should try to use the U-Boot API when found.
* the arch part can make use of cpu features (like timer register)
* the ppc code enables the FPU in the MSR, since it's used by vsnprintf(),
which at least saves one FP register in its prologue.

src/system/boot/platform/u-boot/arch/arm/Jamfile

@@ -15,7 +15,7 @@ KernelMergeObject boot_platform_u-boot_arm.o :
 	#arch_mmu.cpp
 	#arch_cpu_asm.S
 	arch_start_kernel.S
-	#cpu.cpp
+	arch_cpu.cpp
 	#mmu.cpp
 	: -fno-pic
 ;

src/system/boot/platform/u-boot/arch/arm/arch_cpu.cpp

@@ -0,0 +1,84 @@
+/*
+ * Copyright 2004-2005, Axel Dörfler, [email protected]. All rights reserved.
+ * Distributed under the terms of the MIT License.
+ *
+ * calculate_cpu_conversion_factor() was written by Travis Geiselbrecht and
+ * licensed under the NewOS license.
+ */
+
+
+#include "cpu.h"
+
+#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
+
+//uint32 gTimeConversionFactor;
+
+
+static void
+calculate_cpu_conversion_factor()
+{
+         #warning U-Boot:TODO!
+}
+
+
+static status_t
+check_cpu_features()
+{
+
+        #warning U-Boot:TODO!
+	return B_OK;
+}
+
+
+//	#pragma mark -
+
+
+extern "C" void
+arch_spin(bigtime_t microseconds)
+{
+	for(bigtime_t i=0;i<microseconds;i=i+1)
+	{
+		/*
+		asm volatile ("mov r0,r0");
+		asm volatile ("mov r0,r0");
+		*/
+	}
+	#warning U-Boot:ARM:TODO!!
+}
+
+
+extern "C" status_t
+boot_arch_cpu_init(void)
+{
+	status_t err = check_cpu_features();
+
+	if (err != B_OK) {
+		panic("You need a Pentium or higher in order to boot!\n");
+		return err;
+	}
+
+	calculate_cpu_conversion_factor();
+
+	gKernelArgs.num_cpus = 1;
+		// this will eventually be corrected later on
+
+	return B_OK;
+}
+

src/system/boot/platform/u-boot/arch/ppc/Jamfile

@@ -15,7 +15,7 @@ KernelMergeObject boot_platform_u-boot_ppc.o :
 	#arch_mmu.cpp
 	#arch_cpu_asm.S
 	arch_start_kernel.S
-	#cpu.cpp
+	arch_cpu.cpp
 	#mmu.cpp
 	: -fno-pic
 ;

src/system/boot/platform/u-boot/arch/ppc/arch_cpu.cpp

@@ -0,0 +1,97 @@
+/*
+ * Copyright 2004-2005, Axel Dörfler, [email protected]. All rights reserved.
+ * Distributed under the terms of the MIT License.
+ *
+ * calculate_cpu_conversion_factor() was written by Travis Geiselbrecht and
+ * licensed under the NewOS license.
+ */
+
+
+#include "cpu.h"
+
+#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/ppc/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
+
+//uint32 gTimeConversionFactor;
+
+
+static void
+calculate_cpu_conversion_factor()
+{
+	#warning U-Boot:TODO!
+}
+
+
+static status_t
+check_cpu_features()
+{
+	uint32 msr;
+
+	// we do need an FPU
+	// on Sam460ex at least U-Boot doesn't enable the FPU for us
+	msr = get_msr();
+	msr |= MSR_FP_AVAILABLE;
+	msr = set_msr(msr);
+
+	if ((msr & MSR_FP_AVAILABLE) == 0) {
+		// sadly panic uses vsnprintf which fails without FPU anyway
+		panic("no FPU!");
+		return B_ERROR;
+	}
+
+	return B_OK;
+}
+
+
+//	#pragma mark -
+
+
+extern "C" void
+arch_spin(bigtime_t microseconds)
+{
+	for(bigtime_t i=0;i<microseconds;i=i+1)
+	{
+		/*
+		asm volatile ("mov r0,r0");
+		asm volatile ("mov r0,r0");
+		*/
+	}
+	#warning U-Boot:PPC:TODO!!
+}
+
+
+extern "C" status_t
+boot_arch_cpu_init(void)
+{
+	status_t err = check_cpu_features();
+
+	if (err != B_OK) {
+		panic("You need a Pentium or higher in order to boot!\n");
+		return err;
+	}
+
+	calculate_cpu_conversion_factor();
+
+	gKernelArgs.num_cpus = 1;
+		// this will eventually be corrected later on
+
+	return B_OK;
+}
+

src/system/boot/platform/u-boot/cpu.cpp

@@ -28,31 +28,13 @@
 #	define TRACE(x) ;
 #endif
 
-//uint32 gTimeConversionFactor;
-
-
-static void
-calculate_cpu_conversion_factor()
-{
-         #warning U-Boot:TODO!
-}
-
-
-static status_t
-check_cpu_features()
-{
-
-        #warning U-Boot:TODO!
-	return B_OK;
-}
-
-
-//	#pragma mark -
-
 
 extern "C" void
 spin(bigtime_t microseconds)
 {
+	#warning U-Boot:TODO!!
+	// TODO: use API if available
+
 	for(bigtime_t i=0;i<microseconds;i=i+1)
 	{
 		/*
@@ -60,19 +42,19 @@ spin(bigtime_t microseconds)
 		asm volatile ("mov r0,r0");
 		*/
 	}
-	#warning U-Boot:TODO!!
+
+	// fallback to arch-specific code
+	//arch_spin(microseconds);
 }
 
 
 extern "C" void
 cpu_init()
 {
-	if (check_cpu_features() != B_OK)
-		panic("You need a Pentium or higher in order to boot!\n");
-
-	calculate_cpu_conversion_factor();
-
 	gKernelArgs.num_cpus = 1;
 		// this will eventually be corrected later on
+
+	if (boot_arch_cpu_init() != B_OK)
+		panic("You need a 6502 or higher in order to boot!\n");
 }
 

src/system/boot/platform/u-boot/cpu.h

@@ -13,6 +13,8 @@
 extern "C" {
 #endif
 
+extern void arch_spin(bigtime_t microseconds);
+extern status_t boot_arch_cpu_init(void);
 extern void cpu_init(void);
 
 #ifdef __cplusplus