add Makefile option `graphic` & cargo feature `nographic`

kernel/Cargo.toml

@@ -12,6 +12,7 @@ no_mmu = []
 # Kernel in M-mode (for riscv32)
 m_mode = ["no_mmu"]
 # (for aarch64 RaspberryPi3)
+nographic = []
 board_raspi3 = ["bcm2837"]
 raspi3_use_generic_timer = ["bcm2837/use_generic_timer"]
 

kernel/Makefile

@@ -12,8 +12,9 @@
 #   d       = int | in_asm | ...    QEMU debug info
 #   mode    = debug | release
 #   LOG     = off | error | warn | info | debug | trace
-#   SFSIMG = SFS image path of user programs
+#   SFSIMG  = <sfsimg>              SFS image path of user programs
 #   smp     = 1 | 2 | ...           SMP core number
+#   graphic = on | off              enable/disable qemu graphical output
 #   board   = fpga                  Only available on riscv32, build without bbl, run on board
 #           | raspi3                Only available on aarch64, run on Raspberry Pi 3 Model B/B+
 #   m_mode                          Only available on riscv32, build for M-Mode, without MMU
@@ -40,10 +41,15 @@ user_obj := build/$(arch)/user.o
 export ARCH = $(arch)
 export SFSIMG = $(user_dir)/build/user-$(arch).img
 
+ifeq ($(arch), aarch64)
+graphic ?= on
+else
+graphic ?= off
+endif
+
 ### qemu options ###
 qemu_opts := \
-	-smp cores=$(smp) \
-	-nographic
+	-smp cores=$(smp)
 
 ifeq ($(arch), x86_64)
 qemu_opts += \
@@ -67,6 +73,10 @@ qemu_opts += \
 	-kernel $(bin)
 endif
 
+ifneq ($(graphic), on)
+qemu_opts += -nographic
+endif
+
 ifdef d
 qemu_opts += -d $(d)
 endif
@@ -78,6 +88,10 @@ features += no_bbl
 endif
 endif
 
+ifneq ($(graphic), on)
+features += nographic
+endif
+
 ifeq ($(board), raspi3)
 # qemu only has generic timer
 # TODO: configure system/generic timer automatically

kernel/src/arch/aarch64/board/raspi3/mod.rs

@@ -22,6 +22,7 @@ pub fn init_serial_early() {
 
 /// Initialize raspi3 drivers
 pub fn init_driver() {
+    #[cfg(not(feature = "nographic"))]
     fb::init();
     timer::init();
 }