lib: Implement simplefb driver for framebuffer management

Signed-off-by: Ivaylo Ivanov <ivo.ivanov.ivanov1@gmail.com>

.gitignore

@@ -4,3 +4,4 @@ asm/*.o
 asm/linker.lds
 board/*/*.o
 soc/*/*.o
+lib/*/*.o

Makefile

@@ -43,8 +43,8 @@ OBJ  =	main.o \
 uniLoader: uniLoader.o
 	$(OBJCPY) -O binary $< $@
 
-uniLoader.o: copy-board-config $(OBJ) asm/linker.lds build-board build-soc
+uniLoader.o: copy-board-config $(OBJ) asm/linker.lds build-board build-soc build-lib
-	$(LD) $(OBJ) board.o soc.o -o $@ --script=asm/linker.lds
+	$(LD) $(OBJ) board.o soc.o lib/simplefb/simplefb.o -o $@ --script=asm/linker.lds
 
 asm/linker.lds: asm/linker.lds.S $(KERNEL_PATH)
 	$(CPP) $< -DKERNEL_PATH=$(KERNEL_PATH) -DDTB_PATH=$(DTB_PATH) -P -o $@
@@ -55,8 +55,11 @@ build-board:
 build-soc:
 	cd soc && make
 
+build-lib:
+	cd lib && make
+
 copy-board-config:
 	cp include/board/board-$(board_codename).h include/board-config.h
 
 clean:
-	-rm *.o asm/linker.lds asm/Start.o uniLoader board/*/*.o include/board-config.h soc/*/*.o
+	-rm *.o asm/linker.lds asm/Start.o uniLoader board/*/*.o include/board-config.h soc/*/*.o lib/*/*.o

include/board/board-dreamlte.h

@@ -9,4 +9,9 @@
 #define PAYLOAD_ENTRY		0x90000000
 #define PAYLOAD_SIZE		0x2000000
 
+#define FRAMEBUFFER_BASE	0xcc000000
+#define FRAMEBUFFER_WIDTH	1440
+#define FRAMEBUFFER_HEIGHT	2960
+#define FRAMEBUFFER_STRIDE	4
+
 #endif // BOARD_DREAMLTE_H_

include/board/board-n61ap.h

@@ -10,4 +10,10 @@
 #define PAYLOAD_ENTRY		0x830000000
 #define PAYLOAD_SIZE		0x2000000
 
+#define FRAMEBUFFER_BASE       0x83e900000
+/* Width is offsetted by 2 */
+#define FRAMEBUFFER_WIDTH      752
+#define FRAMEBUFFER_HEIGHT     1334
+#define FRAMEBUFFER_STRIDE     4
+
 #endif // BOARD_N61AP_H_

include/lib/simplefb.h

@@ -0,0 +1,35 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+/*
+ * Copyright (c) 2022, Ivaylo Ivanov <ivo.ivanov.ivanov1@gmail.com>
+ * Copyright (c) 2022, Markuss Broks <markuss.broks@gmail.com>
+ * Copyright (c) 2022, Michael Srba <Michael.Srba@seznam.cz>
+ */
+
+#ifndef SIMPLEFB_H_	/* Include guard */
+#define SIMPLEFB_H_
+
+typedef struct _color {
+	int r;
+	int g;
+	int b;
+} color;
+
+typedef struct _font_params {
+	int width;
+	int height;
+} font_params;
+
+font_params get_font_params(void);
+
+long unsigned int strlen(const char *p) {
+	unsigned int i = 0;
+
+	while(*p != '\0') {
+		i++;
+		p++;
+	}
+
+    return i;
+}
+
+#endif

include/main.h

@@ -10,6 +10,9 @@ extern void load_kernel(void* dtb, void* x1, void* x2, void* x3, void* kernel);
 extern void soc_init(void);
 extern void board_init(void);
 
+extern void draw_text(volatile char *fb, char *text, int textX, int textY);
+extern void debug_printfb(volatile char *fb, char *text, int textX, int width, int stride);
+
 /* Define our own 128 bit memcpy */
 void memcpy(void *dest, void *src, int size)
 {

lib/Makefile

@@ -0,0 +1,27 @@
+# SPDX-License-Identifier: GPL-2.0
+
+#
+# Compiler defines
+#
+CCPREFIX?=aarch64-linux-gnu-
+CC=$(CCPREFIX)gcc
+CPP=$(CCPREFIX)cpp
+LD=$(CCPREFIX)ld
+OBJCPY=$(CCPREFIX)objcopy
+
+#
+# Compiler flags
+#
+CFLAGS = -march=armv8-a -Wall -nodefaultlibs	\
+         -nostdlib -nostartfiles -fno-builtin	\
+         -nostdinc -Wstrict-prototypes -std=gnu11 \
+         -Wno-main -I'../include'
+
+#
+# Split BOARD definition into 2 parts - manufacturer and codename
+#
+split_board := $(subst -, ,$(BOARD:%=%))
+board_manu := $(word 1,$(split_board))
+board_codename := $(word 2,$(split_board))
+
+all: simplefb/simplefb.o

lib/simplefb/simplefb.c

@@ -0,0 +1,80 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+/*
+ * Copyright (c) 2022, Ivaylo Ivanov <ivo.ivanov.ivanov1@gmail.com>
+ * Copyright (c) 2022, Markuss Broks <markuss.broks@gmail.com>
+ * Copyright (c) 2022, Michael Srba <Michael.Srba@seznam.cz>
+ */
+
+#include <lib/simplefb.h>
+#include <lib/font.h>
+
+int debug_linecount = 0;
+
+void clean_fb(volatile char *fb, char *text, int width, int height, int stride) {
+	for (volatile char *addr = fb; addr < fb + (width * height * stride); addr += stride)
+		*(int*) (addr) = 0x0;
+}
+
+void draw_pixel(volatile char *fb, int x, int y, int width, int stride) {
+	long int location = (x * stride) + (y * width * stride);
+
+	*(fb + location) = 255;	// Blue
+	*(fb + location + 1) = 255;	// Green
+	*(fb + location + 2) = 255;	// Red
+	*(fb + location + 3) = 255;	// Full opacity
+}
+
+void draw_horizontal_line(volatile char *fb, int x1, int x2, int y, color c, int width, int stride) {
+	for (int i = x1; i < x2; i++)
+		draw_pixel(fb, i, y, width, stride);
+}
+
+void draw_vertical_line(volatile char *fb, int x, int y1, int y2, color c, int width, int stride) {
+	for (int i = y1; i < y2; i++)
+		draw_pixel(fb, x, i, width, stride);
+}
+
+void draw_filled_rectangle(volatile char *fb, int x1, int y1, int w, int h, color c, int width, int stride) {
+	for (int i = y1; i < (y1 + h); i++)
+		draw_horizontal_line(fb, x1, (x1 + w), i, c, width, stride);
+}
+
+void draw_text(volatile char *fb, char *text, int textX, int textY, int width, int stride) {
+	// loop through all characters in the text string
+	int l = strlen(text);
+
+	for (int i = 0; i < l; i++) {
+		if(text[i] < 32)
+			continue;
+
+		int ix = font_index(text[i]);
+		unsigned char *img = letters[ix];
+
+		for (int y = 0; y < FONTH; y++) {
+			unsigned char b = img[y];
+
+			for (int x = 0; x < FONTW; x++) {
+				if (((b << x) & 0b10000000) > 0)
+					draw_pixel(fb, textX + i * FONTW + x, textY + y, width, stride);
+			}
+		}
+	}
+}
+
+void debug_printfb(volatile char *fb, char *text, int textX, int width, int stride) {
+	/* IMPORTANT: Limit the linecount */
+	if(debug_linecount > 100 || debug_linecount < 0)
+		debug_linecount = 0;
+
+	draw_text(fb, "[uniLoader] ", textX, (20 + (debug_linecount * 30)), width, stride);
+	draw_text(fb, text, textX + 96, (20 + (debug_linecount * 30)), width, stride);
+
+	debug_linecount++;
+}
+
+/* Helper functions */ 
+font_params get_font_params() {
+	font_params params = {.width=FONTW, .height=FONTH};
+
+	return params;
+}

main.c

@@ -8,11 +8,17 @@
 #include <board-config.h>
 
 void main(void* dt, void* kernel) {
+	/* C entry */
+
 	/* Initialize SoC and Board specific peripherals/quirks */
 	soc_init();
+	debug_printfb((char*)FRAMEBUFFER_BASE, "soc_init() passed!", 0, FRAMEBUFFER_WIDTH, FRAMEBUFFER_STRIDE);
+
 	board_init();
+	debug_printfb((char*)FRAMEBUFFER_BASE, "board_init() passed!", 0, FRAMEBUFFER_WIDTH, FRAMEBUFFER_STRIDE);
 
 	/* Copy kernel to memory and boot  */
+	debug_printfb((char*)FRAMEBUFFER_BASE, "Booting linux...", 0, FRAMEBUFFER_WIDTH, FRAMEBUFFER_STRIDE);
 	memcpy((void*)PAYLOAD_ENTRY, kernel, PAYLOAD_SIZE);
 	load_kernel(dt, 0, 0, 0, (void*)PAYLOAD_ENTRY);	
 }