factor out print functions

Makefile

@@ -14,13 +14,16 @@ start.o: start.S
 main.o: main.c
 	$(GCC) $(CFLAGS) -c $^
 
+print.o: print.c
+	$(GCC) $(CFLAGS) -c $^
+
 zimage-in.o: $(ZIMAGE_IN)
 	$(OBJCOPY) -I binary -O $(BINFMT) -B arm $(ZIMAGE_IN) $@
 
 dtb-in.o: $(DTB_IN)
 	$(OBJCOPY) -I binary -O $(BINFMT) -B arm $(DTB_IN) $@
 
-matcher: start.o main.o zimage-in.o dtb-in.o
+matcher: start.o main.o print.o zimage-in.o dtb-in.o
 	$(LD) $(LDFLAGS) -T matcher.lds -o matcher $^
 
 matcher.bin: matcher

main.c

@@ -1,38 +1,18 @@
 #include "types.h"
 #include "atags.h"
+#include "print.h"
 
-static void putch(char c)
-{
-	int i;
-	volatile __u32 *reg = (volatile __u32 *) 0x40100000;
-
-	*reg = c;
-
-	for (i = 0; i < 100; i++)
-		asm("nop");
-}
-
-static void putstr(const char *s)
-{
-	while (*s) {
-		putch(*s);
-		if (*s == '\n')
-			putch('\r');
-		s++;
-	}
-}
-
-extern void *_binary____linux_arch_arm_boot_zImage_start;
-extern void *_binary____linux_dtb_start;
+extern __u32 _binary____linux_arch_arm_boot_zImage_start;
+extern __u32 _binary____linux_dtb_start;
 
+void init(__u32 dummy, __u32 machid, const struct tag *tags) __attribute__ ((noreturn));
 void init(__u32 dummy, __u32 machid, const struct tag *tags)
 {
-	int i;
 	__u32 system_rev = 0;
 	const struct tag *t;
-	void (*start_kernel)(__u32 dummy, __u32 machid, void *dtb);
-	void *zimage = _binary____linux_arch_arm_boot_zImage_start;
-	void *dtb = _binary____linux_dtb_start;
+	void (*start_kernel)(__u32 dummy, __u32 machid, void *dtb) __attribute__ ((noreturn));
+	void *zimage = &_binary____linux_arch_arm_boot_zImage_start;
+	void *dtb = &_binary____linux_dtb_start;
 
 	putstr("++ Impedance Matcher (3rd stage loader) ++\n");
 
@@ -45,10 +25,13 @@ void init(__u32 dummy, __u32 machid, const struct tag *tags)
 		}
 	}
 
-	putstr("Booting into Linux kernel ...\n");
+	putstr("Booting into Linux kernel @0x");
+	printhex((__u32) zimage);
+	putstr(" with DTB blob @0x");
+	printhex((__u32) dtb);
+	putstr("\n");
 
 	start_kernel = zimage;
-	start_kernel(dummy, 0xffff, 0);
-	//start_kernel(dummy, 0xffff, dtb);
+	start_kernel(0, 0xffff, dtb);
 }
 

matcher.lds

@@ -2,4 +2,5 @@ SECTIONS {
 	. = 0xa0008000;
 	.text : { * (.text); }
 	.data : { * (.data); }
+	.rodata : { * (.rodata); }
 }

print.c

@@ -0,0 +1,38 @@
+#include "types.h"
+#include "print.h"
+
+void putch(char c)
+{
+	int i;
+	volatile __u32 *reg = (volatile __u32 *) 0x40100000;
+
+	*reg = c;
+
+	for (i = 0; i < 100; i++)
+		asm("nop");
+}
+
+static const char hexdigets[] =
+	{ '0', '1', '2', '3', '4', '5', '6', '7',
+	  '8', '9', 'a', 'b', 'c', 'd', 'e', 'f' };
+
+void printhex(__u32 u)
+{
+	int i;
+
+	for (i = 0; i < 8; i++) {
+		__u32 c = u >> (28 - (i * 4));
+		putch(hexdigets[c & 0xf]);
+	}
+}
+
+void putstr(const char *s)
+{
+	while (*s) {
+		putch(*s);
+		if (*s == '\n')
+			putch('\r');
+		s++;
+	}
+}
+

print.h

@@ -0,0 +1,8 @@
+#ifndef _PRINT_H
+#define _PRINT_H
+
+void putch(char c);
+void printhex(__u32 u);
+void putstr(const char *s);
+
+#endif /* _PRINT_H */