search for bootloader inputs in installed share dir

We remove the hard-coded default bootloader as part of this, and instead
hard-code the name of an installed default bootloader input.

2 files changed, 23 insertions, 24 deletions

diff --git a/Makefile b/Makefile
index 9aeb8b7..925dbc2 100644
--- a/Makefile
+++ b/Makefile
@@ -50,6 +50,11 @@ share/boot/%: boot/%.elf
 %.o: %.c
 	$(CC) $(CFLAGS) -c $< -o $@
 
+src/saturn-mkboot.o: src/paths.h
+
+src/paths.h: config.mak
+	echo "#define DATA_PATH \"$(sharedir)\"" > $@
+
 $(DESTDIR)$(bindir)/%: bin/%
 	$(INSTALL) -D $< $@
 
diff --git a/src/saturn-mkboot.c b/src/saturn-mkboot.c
index 63e7bb6..43e1a85 100644
--- a/src/saturn-mkboot.c
+++ b/src/saturn-mkboot.c
@@ -6,6 +6,7 @@
 #include <string.h>
 
 #include "bootinfo.h"
+#include "paths.h"
 #include "symbols.h"
 
 static struct systemid sysid = {
@@ -66,35 +67,30 @@ static int write_output(FILE *fp)
 	return ferror(fp) ? -1 : 0;
 }
 
-static size_t default_ip(char *out)
+static FILE *open_installed_boot_file(const char *filename)
 {
-	size_t size = 0;
-
-	out[size++] = 0xd0;                          /* mov.l addr, r0 */
-	out[size++] = 0x01;
-	out[size++] = 0x40;                          /* jmp   @r0 */
-	out[size++] = 0x2b;
-	out[size++] = 0x00;                          /* nop */
-	out[size++] = 0x09;
-	out[size++] = 0x00;                          /* nop */
-	out[size++] = 0x09;
-	out[size++] = sysid.load_addr >> 24 & 0xff;  /* addr: .long <sysid.load_addr> */
-	out[size++] = sysid.load_addr >> 16 & 0xff;
-	out[size++] = sysid.load_addr >>  8 & 0xff;
-	out[size++] = sysid.load_addr >>  0 & 0xff;
+	static const char *bootpath = DATA_PATH "/boot";
+	char *path = malloc(strlen(bootpath) + strlen(filename) + 2);
+	if (!path) return NULL;
+	sprintf(path, "%s/%s", bootpath, filename);
+	return fopen(path, "rb");
+}
 
-	return size;
+static FILE *open_boot_file(const char *filename)
+{
+	FILE *fp = fopen(filename, "rb");
+	if (fp) return fp;
+	if (!strchr(filename, '/')) return open_installed_boot_file(filename);
+	return NULL;
 }
 
-static size_t load_ip(char *filename, char *out, size_t maxsize)
+static size_t load_ip(char *out, size_t maxsize)
 {
-	FILE  *fp;
 	size_t size;
+	FILE *fp = ipfile ? open_boot_file(ipfile) : open_installed_boot_file("simple");
 	const char *errprefix = "Error loading initial program";
 
-	if (!(fp = fopen(filename, "rb"))) {
-		goto fail_perror;
-	}
+	if (!fp) goto fail_perror;
 	if ((size = fread(out, 1, maxsize, fp)) < maxsize) {
 		/* read fewer than requested amount. determine if we hit error or eof */
 		if (ferror(fp)) {
@@ -252,9 +248,7 @@ int main(int argc, char **argv)
 		sysid.bootsize += 32;
 	}
 
-	ipsize = ipfile
-		? load_ip(ipfile, ipout, sizeof ipbuf - (ipout - ipbuf))
-		: default_ip(ipout);
+	ipsize = load_ip(ipout, sizeof ipbuf - (ipout - ipbuf));
 	if (ipsize == -1) goto fail;
 	sysid.bootsize += ipsize;