kboot/gpu: Add "no-map" property for reserved memory nodes

Without this property u-boot will add reserved memory regions to the
EFI memory map with the wrong type. This results in Linux mapping it
and thus breaking the intended use in the asahi driver.

Signed-off-by: Janne Grunau <[email protected]>

src/kboot_gpu.c

@@ -395,6 +395,9 @@ static int dt_set_region(void *dt, int sgx, const char *name, const char *path)
     if (fdt_setprop_inplace(dt, node, "reg", reg, sizeof(reg)))
         bail("FDT: GPU: failed to set reg prop for %s\n", path);
 
+    if (fdt_setprop_empty(dt, node, "no-map"))
+        bail("FDT: GPU: failed to set no-map prop for %s\n", path);
+
     return 0;
 }
 
@@ -643,6 +646,13 @@ int dt_set_gpu(void *dt)
     if (dt_set_region(dt, sgx, "gpu-region", "/reserved-memory/uat-ttbs"))
         return -1;
 
+    // refresh gpu dt node offset after modifying the dt in dt_set_region()
+    gpu = fdt_path_offset(dt, "gpu");
+    if (gpu < 0) {
+        printf("FDT: GPU: gpu alias not found in device tree\n");
+        return 0;
+    }
+
     if (firmware_set_fdt(dt, gpu, "apple,firmware-version", &os_firmware))
         return -1;