ubb-vga2: non-contiguous allocation of frame buffer memory

- ubb-vga.h (calloc_phys_vec), physmem.c: non-contiguous memory allocator
  (for now, without really considering any mapping to physical memory)
- Makefile (OBJS): added physmem.o
- ubb-vga.h (grabfb), grabfb.c (grabfb): API change for non-contiguous
  frame buffer
- ubb-vga.h (ppmimg), ppmimg.c (convert, ppmimg): API change for
  non-contiguous frame buffer
- ubb-vga.h (tstimg), tstimg.c (pixel, color_bars, grill, grid, sides,
  dot, line45, arc, printc, text, ctext, tstimg): API change for
  non-contiguous frame buffer
- tstimg.c (tstimg): we no longer need to clear the frame buffer
- ubb-vga.c (frame, session, main): use a vector of line buffers instead
  of a contiguous frame buffer

ubb-vga/Makefile

@@ -3,7 +3,7 @@ CC=mipsel-linux-gcc
 
 CFLAGS=-Wall -g -O9 -march=mips32
 LDFLAGS=-lm
-OBJS=ubb-vga2.o grabfb.o tstimg.o ppm.o ppmimg.o ccube.o
+OBJS=ubb-vga2.o grabfb.o tstimg.o ppm.o ppmimg.o ccube.o physmem.o
 
 .PHONY:		all asm sch clean spotless
 

ubb-vga/grabfb.c

@@ -17,10 +17,10 @@
 #include "ubb-vga.h"
 
 
-void grabfb(void *f, int xres, int yres)
+void grabfb(void **f, int xres, int yres)
 {
 	uint32_t *fb = map(0x01d00000, 4*320*240);
-	uint8_t *p = f;
+	uint8_t *p, *q;
 	int x, y;
 	uint32_t pix;
 	uint8_t r, g, b;
@@ -28,14 +28,16 @@ void grabfb(void *f, int xres, int yres)
 	assert(xres == 640);
 	assert(yres == 480);
 	for (y = 0; y != 240; y++) {
+		p = f[y*2];
+		q = f[y*2+1];
 		for (x = 0; x != 320; x++) {
 			pix = *fb++;
 			r = pix >> 16;
 			g = pix >> 8;
 			b = pix;
-			p[0] = p[320] = ccube_map(r, g, b)*0x11;
+			*p = *q = ccube_map(r, g, b)*0x11;
 			p++;
+			q++;
 		}
-		p += 320;
 	}
 }

ubb-vga/physmem.c

@@ -0,0 +1,35 @@
+/*
+ * physmem.c - Physical memory allocator
+ *
+ * Written 2011 by Werner Almesberger
+ * Copyright 2011 Werner Almesberger
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 2 of the License, or
+ * (at your option) any later version.
+ */
+
+
+#include <string.h>
+#include <unistd.h>
+#include <sys/types.h>
+
+
+/*
+ * dummy implementation
+ */
+
+
+void **calloc_phys_vec(size_t n, size_t size)
+{
+	void **vec;
+	int i;
+
+	vec = sbrk(sizeof(void *)*n);
+	for (i = 0; i != n; i++) {
+		vec[i] = sbrk(size);
+		memset(vec[i], 0, size);
+	}
+	return vec;
+}

ubb-vga/ppmimg.c

@@ -22,25 +22,28 @@
 char *img_name;
 
 
-static void convert(uint8_t *f, int xres, int yres, uint8_t *ppm)
+static void convert(void **f, int xres, int yres, uint8_t *ppm)
 {
 	int x, y;
+	uint8_t *p;
 	uint8_t v, last = 0;
 
-	for (y = 0; y != yres; y++)
+	for (y = 0; y != yres; y++) {
+		p = f[y];
 		for (x = 0; x != xres; x++) {
 			v = ccube_map(ppm[0], ppm[1], ppm[2]);
 			if (x & 1) {
-				*f++ = last | v;
+				*p++ = last | v;
 			} else {
 				last = v << 4;
 			}
 			ppm += 3;
 		}
+	}
 }
 
 
-void ppmimg(void *f, int xres, int yres)
+void ppmimg(void **f, int xres, int yres)
 {
 	uint8_t *ppm;
 	int xr = 0, yr = 0;

ubb-vga/tstimg.c

@@ -40,11 +40,11 @@
 #define	WHITE	0xf
 
 
-static void pixel(void *f, int xres, int x, int y, uint8_t c)
+static void pixel(void **f, int xres, int x, int y, uint8_t c)
 {
 	uint8_t *p;
 
-	p = f+((y*xres+x) >> 1);
+	p = f[y]+(x >> 1);
 	if (x & 1)
 		*p = (*p & 0xf0) | c;
 	else
@@ -61,7 +61,7 @@ static void pixel(void *f, int xres, int x, int y, uint8_t c)
 #define	CBAR_Y1	0.75
 
 
-static void color_bars(void *f, int xres, int yres, ...)
+static void color_bars(void **f, int xres, int yres, ...)
 {
 	int i, x, y;
 	uint8_t c;
@@ -81,7 +81,7 @@ static void color_bars(void *f, int xres, int yres, ...)
 #define	GRID	50
 
 
-static void grill(void *f, int ares, int bres, int swap)
+static void grill(void **f, int ares, int bres, int swap)
 {
 	int n, o;
 	int i, a, b;
@@ -119,7 +119,7 @@ static void grill(void *f, int ares, int bres, int swap)
 }
 
 
-static void grid(void *f, int xres, int yres)
+static void grid(void **f, int xres, int yres)
 {
 	grill(f, xres, yres, 0);
 	grill(f, yres, xres, 1);
@@ -129,7 +129,7 @@ static void grid(void *f, int xres, int yres)
 /* ----- Diagonal lines meeting at the sides ------------------------------- */
 
 
-static void sides(void *f, int xres, int yres)
+static void sides(void **f, int xres, int yres)
 {
 	int i;
 
@@ -151,7 +151,7 @@ static void sides(void *f, int xres, int yres)
 /* ----- Text -------------------------------------------------------------- */
 
 
-static void dot(void *f, int xres, int x, int y, int color, int side)
+static void dot(void **f, int xres, int x, int y, int color, int side)
 {
 	int xi, yi;
 
@@ -161,7 +161,7 @@ static void dot(void *f, int xres, int x, int y, int color, int side)
 }
 
 
-static void line45(void *f, int xres, int x, int y, int dx, int dy, int n,
+static void line45(void **f, int xres, int x, int y, int dx, int dy, int n,
      uint8_t color, int side)
 {
 	while (n--) {
@@ -173,7 +173,7 @@ static void line45(void *f, int xres, int x, int y, int dx, int dy, int n,
 }
 
 
-static void arc(void *f, int xres, int x, int y, int n, int q,
+static void arc(void **f, int xres, int x, int y, int n, int q,
     uint8_t color, int side)
 {
 	int dx, dy;
@@ -192,7 +192,7 @@ static void arc(void *f, int xres, int x, int y, int n, int q,
 }
 
 
-static void printc(void *f, int xres, int x, int y, char c, int n,
+static void printc(void **f, int xres, int x, int y, char c, int n,
     uint8_t color, int side)
 {
 	switch (c) {
@@ -299,7 +299,7 @@ static void printc(void *f, int xres, int x, int y, char c, int n,
 }
 
 
-static void text(void *f, int xres, int x, int y, const char *s, int n,
+static void text(void **f, int xres, int x, int y, const char *s, int n,
     uint8_t color, int side)
 {
 	while (*s) {
@@ -311,7 +311,7 @@ static void text(void *f, int xres, int x, int y, const char *s, int n,
 
 
 
-static void ctext(void *f, int xres, int x, int y, const char *s, int n,
+static void ctext(void **f, int xres, int x, int y, const char *s, int n,
     uint8_t color, int side)
 {
 	text(f, xres, x+n*(1-3*(int) strlen(s))/2, y-2*n, s, n, color, side);
@@ -321,11 +321,10 @@ static void ctext(void *f, int xres, int x, int y, const char *s, int n,
 /* ----- Generate the test image ------------------------------------------- */
 
 
-void tstimg(void *f, int xres, int yres)
+void tstimg(void **f, int xres, int yres)
 {
 	char buf[20];
 
-	memset(f, 0, xres*yres/2);
 	grid(f, xres, yres);
 	sides(f, xres, yres);
 	color_bars(f, xres, yres);

ubb-vga/ubb-vga.h

@@ -31,18 +31,22 @@ void *map(off_t addr, size_t size);
 uint8_t ccube_map(uint8_t r, uint8_t g, uint8_t b);
 void ccube_init(void);
 
+/* physmem.c */
+
+void **calloc_phys_vec(size_t n, size_t size);
+
 /* grabfb.c */
 
-void grabfb(void *f, int xres, int yres);
+void grabfb(void **f, int xres, int yres);
 
 /* tstimg.c */
 
-void tstimg(void *f, int xres, int yres);
+void tstimg(void **f, int xres, int yres);
 
 /* ppmimg.c */
 
 extern char *img_name;
 
-void ppmimg(void *f, int xres, int yres);
+void ppmimg(void **f, int xres, int yres);
 
 #endif /* !UBB_VGA_H */

ubb-vga/ubb-vga2.c

@@ -328,9 +328,9 @@ static void hdelay(int cycles)
 }
 
 
-static void frame(const uint32_t *f)
+static void frame(void *const *f)
 {
-	const uint32_t *p;
+	void *const *p;
 
 	/* VSYNC */
 	PDDATC = VSYNC;
@@ -351,8 +351,8 @@ static void frame(const uint32_t *f)
 	PDDATS = HSYNC;
 	until(mode->line_cycles-US(0.79));
 
-	for (p = f; p != f+mode->yres*mode->line_words; p += mode->line_words)
+	for (p = f; p != f+mode->yres; p++)
-		line(p);
+		line(*p);
 
 	/* Back porch */
 	hdelay(14);
@@ -362,18 +362,13 @@ static void frame(const uint32_t *f)
 /* ----- Command-line parsing and main loop -------------------------------- */
 
 
-static void session(void (*gen)(void *fb, int xres, int yres), int frames)
+static void session(void (*gen)(void **fb, int xres, int yres), int frames)
 {
-	uint32_t *f;
+	void **f;
 	int i;
 
-	f = malloc((mode->yres*mode->line_words)*4);
-	if (!f) {
-		perror("malloc");
-		exit(1);
-	}
-	memset(f, 0, sizeof(f));
 	ccube_init();
+	f = calloc_phys_vec(mode->yres, mode->xres/2);
 	gen(f, mode->xres, mode->yres);
 
 	disable_interrupts();
@@ -400,7 +395,7 @@ static void usage(const char *name)
 
 int main(int argc, char *const *argv)
 {
-	void (*gen)(void *fb, int xres, int yres) = grabfb;
+	void (*gen)(void **fb, int xres, int yres) = grabfb;
 	int frames;
 	int c;