seminaries/qtmips/fb-simple: example to draw on QtMips LCD display.

Signed-off-by: Pavel Pisa <pisa@cmp.felk.cvut.cz>

seminaries/qtmips/fb-simple/.gitignore

+*.o
+fb-simple
+*~
+

seminaries/qtmips/fb-simple/Makefile

+ARCH=mips-elf
+
+SOURCES = fb-simple.c crt0local.S
+TARGET_EXE = fb-simple
+
+CC=$(ARCH)-gcc
+CXX=$(ARCH)-g++
+AS=$(ARCH)-as
+LD=$(ARCH)-ld
+OBJCOPY=$(ARCH)-objcopy
+
+#ARCHFLAGS += -march=mips3
+ARCHFLAGS += -fno-lto
+#ARCHFLAGS += -mno-shared
+
+CFLAGS  += -ggdb -O3 -Wall
+CXXFLAGS+= -ggdb -O3 -Wall
+AFLAGS  += -ggdb
+LDFLAGS += -ggdb
+LDFLAGS += -nostartfiles
+LDFLAGS += -static
+
+CFLAGS  += $(ARCHFLAGS)
+CXXFLAGS+= $(ARCHFLAGS)
+AFLAGS  += $(ARCHFLAGS)
+LDFLAGS += $(ARCHFLAGS)
+
+OBJECTS += $(filter %.o,$(SOURCES:%.c=%.o))
+OBJECTS += $(filter %.o,$(SOURCES:%.cpp=%.o))
+OBJECTS += $(filter %.o,$(SOURCES:%.S=%.o))
+
+all : default
+
+.PHONY : default clean dep all
+
+%.o:%.S
+	$(CC) -D__ASSEMBLY__ $(AFLAGS) -c $< -o $@
+
+%.o:%.c
+	$(CC) $(CFLAGS) $(CPPFLAGS) -c $< -o $@
+
+%.o:%.cpp
+	$(CXX) $(CXXFLAGS) $(CPPFLAGS) -c $<
+
+%.s:%.c
+	$(CC) $(CFLAGS) $(CPPFLAGS) -S $< -o $@
+
+default : $(TARGET_EXE)
+
+$(TARGET_EXE) : $(OBJECTS)
+	$(CC) $(LDFLAGS) $^ -o $@
+
+dep: depend
+
+depend: $(SOURCES) *.h
+	echo '# autogenerated dependencies' > depend
+ifneq ($(filter %.c,$(SOURCES)),)
+	$(CC) $(CFLAGS) $(CPPFLAGS) -w -E -M $(filter %.c,$(SOURCES)) \
+	 >> depend
+endif
+ifneq ($(filter %.cpp,$(SOURCES)),)
+	$(CXX) $(CXXFLAGS) $(CPPFLAGS) -w -E -M $(filter %.cpp,$(SOURCES)) \
+	 >> depend
+endif
+
+clean:
+	rm -f *.o *.a $(OBJECTS) $(TARGET_EXE) depend
+	
+#mips-elf-objdump --source -M no-aliases,reg-names=numeric exam1-asm
+
+-include depend

seminaries/qtmips/fb-simple/crt0local.S

+/* minimal replacement of crt0.o provided by C library */
+
+#define zero	$0
+#define AT	$1
+#define v0 	$2
+#define v1	$3
+#define a0	$4
+#define a1	$5
+#define a2	$6
+#define	a3	$7
+
+#define t0	$8
+#define t1	$9
+#define t2	$10
+#define t3	$11
+#define t4	$12
+#define t5	$13
+#define t6	$14
+#define t7	$15
+#define t8	$24
+#define t9	$25
+#define k0	$26
+#define k1	$27
+
+#define s0	$16
+#define s1	$17
+#define s2	$18
+#define s3	$19
+#define s4	$20
+#define s5	$21
+#define s6	$22
+#define s7	$23
+
+#define gp	$28
+#define sp	$29
+#define fp	$30
+#define ra	$31
+
+.globl main
+.globl __start
+.globl _start
+.set noat
+.set noreorder
+.ent __start
+
+.text
+
+__start:
+_start:
+	bal     next
+	nop
+next:   .set    noreorder
+        .cpload $31
+        .set    reorder
+
+	addi    a0, zero, 0
+	addi    a1, zero, 0
+	jal     main
+quit:
+	addi    a0, zero, 0
+	addi    v0, zero, 4001  /* SYS_exit */
+
+	syscall
+
+loop:	break
+        beq     zero, zero, loop
+	nop
+
+.end __start

seminaries/qtmips/fb-simple/fb-simple.c

+#include <stdio.h>
+#include <stdint.h>
+
+int main(void)
+{
+
+  volatile uint16_t *fb = (volatile uint16_t *)0xffe00000;
+  int x, y, i;
+  int width = 480;
+  int height = 320;
+
+  for (i = 0; i < width; i++) {
+    x = i;
+    y = 0;
+    fb[y * width + x] = 0xf800;
+    y = height - 1;
+    fb[y * width + x] = 0xf800;
+  }
+
+  for (i = 1; i < height -1; i++) {
+    x = 0;
+    y = i;
+    fb[y * width + x] = 0xf800;
+    x = width - 1;
+    fb[y * width + x] = 0xf800;
+  }
+
+
+  while (1) {
+    for (y = 1; y < height - 1; y++) {
+      for (i = 0; i < 200; i++) {
+        x = (y & 0xff) + i;
+        fb[y * width + x] = 0xffff;
+      }
+      for (i = 0; i < 10; i++) {
+        x = (y & 0xff) + i + 200;
+        fb[y * width + x] = 0xf800;
+      }
+      for (i = 0; i < 10; i++) {
+        x = (y & 0xff) + i + 210;
+        fb[y * width + x] = 0x07e0;
+      }
+      for (i = 0; i < 10; i++) {
+        x = (y & 0xff) + i + 220;
+        fb[y * width + x] = 0x001f;
+      }
+    }
+    // no reorder or combine memory accesses over this sequesntial point
+    //__asm__ __volatile__ ("" : : : "memory");
+    __asm__ __volatile__ ("break\n" : : : "memory");
+  }
+  return 0;
+}