Ensuring the HAL identification function gets access to the real mmap…

… function, while others can rely on the syscall instead

src/Makefile

@@ -1,4 +1,4 @@
 SRC := $(shell find ./ -name '*.c')
 
 divinus:
-	$(CC) $(SRC) -I src -rdynamic $(OPT) -o ../$@
+	$(CC) $(SRC) -I src -rdynamic -Wl,--wrap=mmap $(OPT) -o ../$@

src/compat.c

@@ -17,5 +17,8 @@ int __fgetc_unlocked(FILE *stream) { return fgetc(stream); }
 double __log_finite(double x) { return log(x); }
 
 void* mmap(void *start, size_t len, int prot, int flags, int fd, uint32_t off) {
-  return (void *)syscall(SYS_mmap2, start, len, prot, flags, fd, off >> 12);
+    return (void*)syscall(SYS_mmap2, start, len, prot, flags, fd, off >> 12);
+}
+void* __wrap_mmap(void *start, size_t len, int prot, int flags, int fd, uint32_t off) {
+    return mmap(start, len, prot, flags, fd, off);
 }

src/hal/support.c

@@ -1,5 +1,7 @@
 #include "support.h"
 
+extern __real_mmap();
+
 void *isp_thread = NULL;
 void *venc_thread = NULL;
 
@@ -32,7 +34,7 @@ bool hal_registry(unsigned int addr, unsigned int *data, hal_register_op op) {
 
     volatile char *mapped_area;
     if (offset != loaded_offset) {
-        mapped_area = mmap(NULL, size, PROT_READ | PROT_WRITE, MAP_SHARED, mem_fd, offset);
+        mapped_area = (void*)__real_mmap(NULL, size, PROT_READ | PROT_WRITE, MAP_SHARED, mem_fd, offset);
         if (mapped_area == MAP_FAILED) {
             fprintf(stderr, "hal_registry mmap error: %s (%d)\n",
                     strerror(errno), errno);