[OpenBIOS] Found out why replacing '\r' with '\n' works

[Programmingkid]

On Apr 18, 2016, at 11:27 PM, Segher Boessenkool wrote:

> On Mon, Apr 18, 2016 at 11:21:51PM -0400, Programmingkid wrote:
>>>> With my patch I saw mostly the same thing except there was also a message that said "this image is not for this platform". I think this proves that the '\r' to '\n' patch is needed.
>>> 
>>> [ long lines ]
>>> 
>>> You need at least four things:
>>> - You need to EVALUATE the boot script per line, not as one string;
>> How do you decide when to end a line? 
> 
> When there is an end-of-line character, or you reach the end of the script.
> 
>>> - CARRET should indeed be treated as end-of-line, for that;
>> Do you mean ^ ? I don't remember any carret characters in the script.
> 
> That is a caret.  CARRET is an OF word, it is the ASCII 13 character.
> "Carriage return".
> 
>>> - Return stack in interpret mode;
>>> - Structure words in interpret mode.  That is at least
>>> 
>>> AHEAD IF THEN  BEGIN AGAIN UNTIL  CASE ENDCASE  DO ?DO LOOP +LOOP
>> 
>> I think it would be easier if I was sent a patch. The forth code for Mac OS 9.2 is located in a file called "Mac OS ROM". Just let me know if you need help obtaining this file. 
> 
> [ long lines ]
> 
> Thanks, but no, of course I have it.

The executing one line at a time idea turned out to be a pretty good idea. That is enough to make Mac OS 9.2 boot. It is also entertaining to watch each executed line be printed to the terminal. Here is the patch:

Index: libopenbios/bootinfo_load.c
===================================================================
--- libopenbios/bootinfo_load.c	(revision 1395)
+++ libopenbios/bootinfo_load.c	(working copy)
@@ -20,7 +20,7 @@
 #include "libopenbios/ofmem.h"
 #include "libc/vsprintf.h"
 
-//#define DEBUG_BOOTINFO
+#define DEBUG_BOOTINFO
 
 #ifdef DEBUG_BOOTINFO
 #define DPRINTF(fmt, args...) \
@@ -116,6 +116,25 @@
 	return LOADER_NOT_SUPPORT;
 }
 
+// Execute the bootscript one line at a time
+static void run_script(char *bootscript)
+{
+    char *ptr;
+    char *buffer = malloc(1000 * sizeof(char));
+    int index = -1, prev_index = 0;
+    ptr = strchr(bootscript, '\r');
+    while (ptr != NULL) {
+        prev_index = index;
+        index = ptr - bootscript;
+        strncpy(buffer, bootscript + prev_index + 1, index - prev_index);
+        buffer[index-prev_index] = '\0';
+        ptr = strchr(bootscript + index + 1, '\r');        
+        DPRINTF("%s\n", buffer);
+        feval(buffer);
+    }
+    free(buffer);
+}
+
 /*
   Parse SGML structure like:
   <chrp-boot>
@@ -262,7 +281,7 @@
 	/* If the payload is bootinfo then we execute it immediately */
 	if (scriptvalid) {
 		DPRINTF("bootscript: %s\n", bootscript);
-		feval(bootscript);
+		run_script(bootscript);
 	}
 	else
 		DPRINTF("Unable to parse bootinfo bootscript\n");