9os

commit f10c64b2c0179267cfdefedc6b0cd4e15739a4c1
parent 8e3f308c38ca57e05cf628bd0040a5b875e6c4fb
Author: Roberto Vargas <roberto.vargas@arm.com>
Date:   Fri, 26 Oct 2018 14:05:24 +0100

Add reloc()

This function is used to dynamically rellocate pointers
that are statically allocated.

Diffstat:
M
include/rcode.h
 | 
2
+-
M
scripts/gentbl.sh
 | 
5
++---
M
src/rmc.c
 | 
18
+++++++++++++-----

3 files changed, 16 insertions(+), 9 deletions(-)
diff --git a/include/rcode.h b/include/rcode.h
@@ -163,5 +163,5 @@ extern uint32_t outm32(uint32_t, void *addr);
 
 /* global constant variables */
 extern const struct rowidx  rowidx[];
-extern const ptrdiff_t handler[];
+extern const void *const handler[];
 extern const char *const ecstr[];
diff --git a/scripts/gentbl.sh b/scripts/gentbl.sh
@@ -36,7 +36,6 @@ sort -n -k1,2 < $in |
 awk '
 BEGIN {
 	print "#include <rcode.h>\n"
-	print "#define from0(f) ((char *) (f) - (char *) 0)\n"
 };
 
 NF == 4 && $1 ~ /[0-9]*/ && $2 ~ /[0-9]*/ && /'$img'/ {
@@ -59,9 +58,9 @@ END {
 	}
 	print "};"
 
-	print "const ptrdiff_t handler[] = {"
+	print "const void *const handler[] = {"
 	for (row in rowcnt)
 		for (col = 0; col < rowcnt[row]; col++)
-			printf "\t[%d] = from0(hdl_%s),\n", begin[row] + col, cmds[row,col]
+			printf "\t[%d] = hdl_%s,\n", begin[row] + col, cmds[row,col]
 	print "};"	
 }' > $tmp && mv $tmp rmctbl.c
diff --git a/src/rmc.c b/src/rmc.c
@@ -74,6 +74,15 @@ panic(const char *msg)
 	dopanic();
 }
 
+static inline void *
+reloc(const void *addr)
+{
+	uintptr_t a = (uintptr_t) addr;
+	uintptr_t off = (uintptr_t) bss->text;
+
+	return (void *) (a + off);
+}
+
 void
 trap(struct trapframe *fp)
 {
@@ -95,7 +104,7 @@ trap(struct trapframe *fp)
 			msg = ecstr[ec];
 		if (!msg)
 			msg = "unknown reason";
-		panicfmt(msg, fp);
+		panicfmt(reloc(msg), fp);
 		halt();
 	}
 
@@ -145,7 +154,7 @@ rmc(Rmucmd *cmd)
 {
 	const struct rowidx *idx;
 	void (*fp)(Rmucmd *cmd);
-	char *bp;
+	void *bp;
 
 	if (cmd->class > 255 || cmd->func > 255)
 		panic("rmc");
@@ -159,9 +168,8 @@ rmc(Rmucmd *cmd)
 	 * because we are linked at address 0 but we can be
 	 * loaded at any address
 	 */
-	bp = bss->text;
-	bp += handler[idx->off + cmd->func];
-	fp = (void (*)(Rmucmd *)) bp;
+	bp = reloc(handler[idx->off + cmd->func]);
+	fp = (void (*) (Rmucmd *)) bp;
 	(*fp)(cmd);
 
 	cmd->fp->x0 = SUCCESS;