Make gpu initialization optional

GPU stuff now requires rust, make it optional

Signed-off-by: Sasha Finkelstein <[email protected]>

Author: WhatAmISupposedToPutHere

Makefile

@@ -64,11 +64,25 @@ ifeq ($(RELEASE),1)
 CFG += RELEASE
 endif
 
+WANT_RUST := 0
+ifeq ($(CHAINLOADING),1)
+CFG += CHAINLOADING
+WANT_RUST := 1
+endif
+ifneq ($(NO_GPU_INIT),1)
+WANT_RUST := 1
+GPU_OBJECTS := kboot_gpu.o
+CFG += DO_GPU_INIT
+else
+GPU_OBJECTS :=
+endif
+
 # Required for no_std + alloc for now
 export RUSTC_BOOTSTRAP=1
+ifeq ($(WANT_RUST),1)
 RUST_LIB := librust.a
-ifeq ($(CHAINLOADING),1)
-CFG += CHAINLOADING
+else
+RUST_LIB :=
 endif
 
 LDFLAGS := -EL -maarch64elf --no-undefined -X -Bsymbolic \
@@ -163,7 +177,7 @@ OBJECTS := \
 	$(MINILZLIB_OBJECTS) $(TINF_OBJECTS) $(DLMALLOC_OBJECTS) $(LIBFDT_OBJECTS) $(RUST_LIB)
 
 FP_OBJECTS := \
-	kboot_gpu.o \
+	$(GPU_OBJECTS) \
 	math/expf.o \
 	math/exp2f_data.o \
 	math/powf.o \

src/kboot.c

@@ -1,5 +1,7 @@
 /* SPDX-License-Identifier: MIT */
 
+#include "../build/build_cfg.h"
+
 #include <stdint.h>
 
 #include "kboot.h"
@@ -47,7 +49,33 @@ static char *chosen_params[MAX_CHOSEN_PARAMS][2];
 
 extern const char *const m1n1_version;
 
+#ifdef DO_GPU_INIT
 int dt_set_gpu(void *dt);
+#else
+static int dt_set_gpu(void *dt)
+{
+    int gpu, node;
+
+    gpu = fdt_path_offset(dt, "gpu");
+    if (gpu >= 0)
+        fdt_setprop_string(dt, gpu, "status", "disabled");
+
+    node = fdt_path_offset(dt, "/reserved-memory/uat-handoff");
+    if (node >= 0)
+        fdt_setprop_string(dt, node, "status", "disabled");
+
+    node = fdt_path_offset(dt, "/reserved-memory/uat-pagetables");
+    if (node >= 0)
+        fdt_setprop_string(dt, node, "status", "disabled");
+
+    node = fdt_path_offset(dt, "/reserved-memory/uat-ttbs");
+    if (node >= 0)
+        fdt_setprop_string(dt, node, "status", "disabled");
+
+    printf("m1n1 was built without rust support, GPU will not be initialized\n");
+    return 0;
+}
+#endif
 
 #define DT_ALIGN 16384
 
@@ -2332,7 +2360,11 @@ static int dt_disable_missing_devs(const char *adt_prefix, const char *dt_prefix
     return ret;
 }
 
-static int dt_transfer_virtios(void)
+#ifdef RELEASE
+__attribute__((unused))
+#endif
+static int
+dt_transfer_virtios(void)
 {
     int path[3];
     path[0] = adt_path_offset(adt, "/arm-io/");