demo: initial commit

1 files changed, 145 insertions, 0 deletions

diff --git a/demo/console.c b/demo/console.c
new file mode 100644
index 0000000..e531b2e
--- /dev/null
+++ b/demo/console.c
@@ -0,0 +1,145 @@
+#include <stdarg.h>
+
+#include "demo.h"
+
+struct lock console_lock;
+
+#define JTAG_UART_BASE           0x30000000
+#define JTAG_UART_DATA           (*(volatile unsigned *)(JTAG_UART_BASE + 0))
+#define JTAG_UART_CONTROL        (*(volatile unsigned *)(JTAG_UART_BASE + 4))
+#define JTAG_UART_CONTROL_RE     (1 << 0)
+#define JTAG_UART_CONTROL_AC     (1 << 10)
+#define JTAG_UART_CONTROL_WSPACE 0xffff0000
+
+#define INTC_BASE       0x30070000
+#define INTC_MASK       (*(volatile unsigned *)(INTC_BASE + 4))
+#define INTC_MASK_TIMER (1 << 0)
+#define INTC_MASK_UART  (1 << 1)
+
+static void print_char(char c)
+{
+	while (!(JTAG_UART_CONTROL & JTAG_UART_CONTROL_WSPACE));
+	JTAG_UART_DATA = (unsigned char)c;
+}
+
+static void print_str(const char *s)
+{
+	while (*s)
+		print_char(*s++);
+}
+
+static void print_hex(unsigned val, unsigned bits)
+{
+	static const char hex_digits[16] = "0123456789abcdef";
+
+	print_str("0x");
+
+	if (bits < 4)
+		bits = 4;
+
+	if (bits > 32)
+		bits = 32;
+
+	bits = bits & ~3;
+	do
+		print_char(hex_digits[(val >> (bits -= 4)) & 0xf]);
+	while (bits);
+}
+
+static void print_dec(unsigned val)
+{
+	char dec[11] = {'\0'};
+	char *next = dec;
+
+	do {
+		*next++ = '0' + val % 10;
+		val /= 10;
+	} while (val && next < dec + sizeof dec); 
+
+	const char *c = next;
+	while (c > dec)
+		print_char(*--c);
+}
+
+void console_init(void)
+{
+	spin_init(&console_lock);
+
+	// Habilitar irqs de entrada uart
+	JTAG_UART_CONTROL = JTAG_UART_CONTROL_RE;
+
+	// Habilitar irqs en controlador de interrupciones
+	INTC_MASK = INTC_MASK_UART;
+
+	// Habilitar irqs en core
+	asm volatile("msr cpsr_c, #0x53");
+}
+
+void print(const char *fmt, ...)
+{
+	va_list args;
+	va_start(args, fmt);
+
+	unsigned irq_save;
+	spin_lock(&console_lock, &irq_save);
+
+	while (!(JTAG_UART_CONTROL & JTAG_UART_CONTROL_AC));
+
+	print_str("cpu");
+	print_dec(this_cpu->num);
+	print_str(": ");
+
+	char c;
+	while ((c = *fmt++)) {
+		if (c != '%') {
+			print_char(c);
+			continue;
+		}
+
+		unsigned val;
+		switch ((c = *fmt++)) {
+			case 'c':
+				print_char((char)va_arg(args, int));
+				break;
+
+			case 'd':
+			case 'i':
+				print_dec((unsigned)va_arg(args, int));
+				break;
+
+			case 'p':
+				print_hex((unsigned)va_arg(args, const void *), 32);
+				break;
+
+			case 'r':
+				val = va_arg(args, unsigned);
+				print_hex(val, va_arg(args, unsigned));
+				break;
+
+			case 'u':
+				print_dec(va_arg(args, unsigned));
+				break;
+
+			case 's':
+				print_str(va_arg(args, const char *));
+				break;
+
+			case 'x':
+				print_hex(va_arg(args, unsigned), 32);
+				break;
+
+			default:
+				print_char('%');
+				if (c)
+					print_char(c);
+
+				break;
+		}
+	}
+
+	print_str("\r\n");
+	JTAG_UART_CONTROL = JTAG_UART_CONTROL_RE | JTAG_UART_CONTROL_AC;
+
+	spin_unlock(&console_lock, irq_save);
+	va_end(args);
+}