U-Boot: Factor-out debug UART setup from FDT for kernel use

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

@@ -24,6 +24,8 @@ extern "C" {
 };
 
 
+extern "C" DebugUART *debug_uart_from_fdt(const void *fdt);
+
 DebugUART* gUART;
 
 static int32 sSerialEnabled = 0;
@@ -96,90 +98,11 @@ serial_cleanup(void)
 }
 
 
-static void
-serial_init_fdt(const void *fdt)
-{
-	const char *name;
-	const char *type;
-	int node;
-	int len;
-	phys_addr_t regs;
-	int32 clock = 0;
-	int32 speed = 0;
-	const void *prop;
-
-	if (fdt == NULL)
-		return;
-
-	name = fdt_get_alias(fdt, "serial");
-	if (name == NULL)
-		name = fdt_get_alias(fdt, "serial0");
-	if (name == NULL)
-		name = fdt_get_alias(fdt, "serial1");
-	// TODO: else use /chosen linux,stdout-path
-	if (name == NULL)
-		return;
-
-	node = fdt_path_offset(fdt, name);
-	//dprintf("serial: using '%s', node %d\n", name, node);
-	if (node < 0)
-		return;
-
-	type = (const char *)fdt_getprop(fdt, node, "device_type", &len);
-	//dprintf("serial: type: '%s'\n", type);
-	if (type == NULL || strcmp(type, "serial"))
-		return;
-
-	// determine the MMIO address
-	// TODO: ppc460 use 64bit addressing, but U-Boot seems to map it below 4G,
-	// and the FDT is not very clear. libfdt is also getting 64bit addr support.
-	// so FIXME someday.
-	prop = fdt_getprop(fdt, node, "virtual-reg", &len);
-	if (prop && len == 4) {
-		regs = fdt32_to_cpu(*(uint32_t *)prop);
-		//dprintf("serial: virtual-reg 0x%08llx\n", (int64)regs);
-	} else {
-		prop = fdt_getprop(fdt, node, "reg", &len);
-		if (prop && len >= 4) {
-			regs = fdt32_to_cpu(*(uint32_t *)prop);
-			//dprintf("serial: reg 0x%08llx\n", (int64)regs);
-		} else
-			return;
-	}
-
-	// get the UART clock rate
-	prop = fdt_getprop(fdt, node, "clock-frequency", &len);
-	if (prop && len == 4) {
-		clock = fdt32_to_cpu(*(uint32_t *)prop);
-		//dprintf("serial: clock %ld\n", clock);
-	}
-
-	// get current speed (XXX: not yet passed over)
-	prop = fdt_getprop(fdt, node, "current-speed", &len);
-	if (prop && len == 4) {
-		speed = fdt32_to_cpu(*(uint32_t *)prop);
-		//dprintf("serial: speed %ld\n", speed);
-	}
-
-	if (fdt_node_check_compatible(fdt, node, "ns16550a") == 1
-		|| fdt_node_check_compatible(fdt, node, "ns16550") == 1) {
-		gUART = arch_get_uart_8250(regs, clock);
-		//dprintf("serial: using 8250\n");
-		// XXX:assume speed is already set
-		(void)speed;
-		return;
-	}
-
-	// for when we can use U-Boot's console
-	panic("Unknown UART type %s", type);
-}
-
-
 extern "C" void
 serial_init(const void *fdt)
 {
 	// first try with hints from the FDT
-	serial_init_fdt(fdt);
+	gUART = debug_uart_from_fdt(fdt);
 
 #ifdef BOARD_UART_DEBUG
 	// fallback to hardcoded board UART

src/system/kernel/arch/ppc/Jamfile

@@ -26,6 +26,8 @@ KernelMergeObject kernel_arch_ppc.o :
 	arch_vm.cpp
 	arch_vm_translation_map.cpp
 	arch_asm.S
+	debug_uart_8250.cpp
+	arch_uart_8250.cpp
 
 	generic_vm_physical_page_mapper.cpp
 	generic_vm_physical_page_ops.cpp

src/system/kernel/platform/u-boot/fdt_support.cpp

@@ -9,6 +9,9 @@
 #include <stdio.h>
 #include <sys/cdefs.h>
 
+#include <arch/generic/debug_uart.h>
+#include <arch/generic/debug_uart_8250.h>
+
 extern "C" {
 #include <fdt.h>
 #include <libfdt.h>
@@ -21,6 +24,7 @@ void *gFDT;
 #endif
 
 extern "C" void dump_fdt(const void *fdt);
+extern "C" DebugUART *debug_uart_from_fdt(const void *fdt);
 
 //#define FDT_DUMP_NODES
 //#define FDT_DUMP_PROPS
@@ -117,3 +121,84 @@ void dump_fdt(const void *fdt)
 }
 
 
+DebugUART *
+debug_uart_from_fdt(const void *fdt)
+{
+	const char *name;
+	const char *type;
+	int node;
+	int len;
+	phys_addr_t regs;
+	int32 clock = 0;
+	int32 speed = 0;
+	const void *prop;
+	DebugUART *uart = NULL;
+
+	if (fdt == NULL)
+		return NULL;
+
+	name = fdt_get_alias(fdt, "serial");
+	if (name == NULL)
+		name = fdt_get_alias(fdt, "serial0");
+	if (name == NULL)
+		name = fdt_get_alias(fdt, "serial1");
+	// TODO: else use /chosen linux,stdout-path
+	if (name == NULL)
+		return NULL;
+
+	node = fdt_path_offset(fdt, name);
+	//dprintf("serial: using '%s', node %d\n", name, node);
+	if (node < 0)
+		return NULL;
+
+	type = (const char *)fdt_getprop(fdt, node, "device_type", &len);
+	//dprintf("serial: type: '%s'\n", type);
+	if (type == NULL || strcmp(type, "serial"))
+		return NULL;
+
+	// determine the MMIO address
+	// TODO: ppc460 use 64bit addressing, but U-Boot seems to map it below 4G,
+	// and the FDT is not very clear. libfdt is also getting 64bit addr support.
+	// so FIXME someday.
+	prop = fdt_getprop(fdt, node, "virtual-reg", &len);
+	if (prop && len == 4) {
+		regs = fdt32_to_cpu(*(uint32_t *)prop);
+		//dprintf("serial: virtual-reg 0x%08llx\n", (int64)regs);
+	} else {
+		prop = fdt_getprop(fdt, node, "reg", &len);
+		if (prop && len >= 4) {
+			regs = fdt32_to_cpu(*(uint32_t *)prop);
+			//dprintf("serial: reg 0x%08llx\n", (int64)regs);
+		} else
+			return NULL;
+	}
+
+	// get the UART clock rate
+	prop = fdt_getprop(fdt, node, "clock-frequency", &len);
+	if (prop && len == 4) {
+		clock = fdt32_to_cpu(*(uint32_t *)prop);
+		//dprintf("serial: clock %ld\n", clock);
+	}
+
+	// get current speed (XXX: not yet passed over)
+	prop = fdt_getprop(fdt, node, "current-speed", &len);
+	if (prop && len == 4) {
+		speed = fdt32_to_cpu(*(uint32_t *)prop);
+		//dprintf("serial: speed %ld\n", speed);
+	}
+
+	if (fdt_node_check_compatible(fdt, node, "ns16550a") == 1
+		|| fdt_node_check_compatible(fdt, node, "ns16550") == 1) {
+		uart = arch_get_uart_8250(regs, clock);
+		//dprintf("serial: using 8250\n");
+		// XXX:assume speed is already set
+		(void)speed;
+	} else {
+		// TODO: handle more UART types
+		// for when we can use U-Boot's console
+		panic("Unknown UART type %s", type);
+	}
+
+	return uart;
+}
+