Add BCM2835 (Raspberry Pi) framebuffer and mailbox implementations

devices/bcm2835_mailbox.c

@@ -0,0 +1,69 @@
+/*
+    Copyright (C) 2012, Aaron Lindsay <aaron@aclindsay.com>
+
+    This file is part of Aedrix.
+
+    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.
+
+    This program is distributed in the hope that it will be useful,
+    but WITHOUT ANY WARRANTY; without even the implied warranty of
+    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+    GNU General Public License for more details.
+
+    You should have received a copy of the GNU General Public License along
+    with this program; if not, write to the Free Software Foundation, Inc.,
+    51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
+ */
+
+#include <types.h>
+
+/* Mailbox Memory-Mapped Registers */
+#define VC_MMU_IO_OFFSET(addr) (addr - 0x7E000000 + 0x20000000)
+
+#define MBOX0_READ	VC_MMU_IO_OFFSET(0x7E00B880)
+/*	MBOX0_READ layout:
+	31-4	data	The 28 bits of data sent to the CPU
+	3-0	channel	The mailbox channel number from which the data originated */
+#define MBOX0_PEEK	VC_MMU_IO_OFFSET(0x7E00B890)	//Read from the mailbox without removing data from it.
+#define MBOX0_SENDER	VC_MMU_IO_OFFSET(0x7E00B894)	//Sender ID (bottom 2 bits only)
+#define MBOX0_STATUS	VC_MMU_IO_OFFSET(0x7E00B898)
+/*	MBOX0_STATUS layout:
+	31	full	Set if the mailbox is full, and thus no more data can be written to it.
+	30	empty	Set if the mailbox is empty, and thus no more data is available to be read from it.
+	29-0		unused? */
+#define MBOX0_CONFIG	VC_MMU_IO_OFFSET(0x7E00B89C)
+#define MBOX0_WRITE	VC_MMU_IO_OFFSET(0x7E00B8A0)	//also MBOX1_READ?
+/*	MBOX0_WRITE layout:
+	31-4	data	The 28 bits of data to be sent
+	3-0	channel	The mailbox channel to send data to */
+
+#define MBOX0_STATUS_FULL	0x80000000
+#define MBOX0_STATUS_EMPTY	0x40000000
+
+
+uint32 mailbox_read(uint32 channel) {
+	uint32 mbox_msg;
+	while (1) {
+		int i;
+		for (i = 0; *(volatile uint32 *)MBOX0_STATUS & MBOX0_STATUS_EMPTY; i++) {
+			if (i >= 1<<20)
+				return 0xFFFFFFFF;
+		}
+
+		mbox_msg = *(volatile uint32 *)MBOX0_READ;
+		if ((mbox_msg & 0xf) == channel)
+			return mbox_msg & ~0xf;
+	}
+} 
+
+void mailbox_write(uint32 channel, uint32 data) {
+	channel &= 0xf;
+	data &= ~0xf;
+
+	while (*(volatile uint32 *)MBOX0_STATUS & MBOX0_STATUS_FULL);
+
+	*(volatile uint32 *)MBOX0_WRITE = channel | data;
+}

devices/bcm2835_videocore.c

@@ -0,0 +1,94 @@
+/*
+    Copyright (C) 2012, Aaron Lindsay <aaron@aclindsay.com>
+
+    This file is part of Aedrix.
+
+    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.
+
+    This program is distributed in the hope that it will be useful,
+    but WITHOUT ANY WARRANTY; without even the implied warranty of
+    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+    GNU General Public License for more details.
+
+    You should have received a copy of the GNU General Public License along
+    with this program; if not, write to the Free Software Foundation, Inc.,
+    51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
+ */
+
+#include <types.h>
+#include <framebuffer.h>
+#include <kmalloc.h>
+#include <print.h>
+#include <devices/bcm2835_mailbox.h>
+
+struct bcm2835_config {
+	uint32 width;
+	uint32 height;
+	uint32 vwidth;
+	uint32 vheight;
+	uint32 pitch;
+	uint32 color_depth;
+	uint32 xoffset;
+	uint32 yoffset;
+	uint32 fb_base_addr;
+	uint32 size;
+};
+
+#define MAILBOX_BUFFER_SIZE (32*4*2)
+#define FB_WIDTH 1024
+#define FB_HEIGHT 768
+
+struct fbdev bcm2835_fb_device;
+
+int bcm2835_videocore_init(struct fb *f, unsigned int color_depth) {
+	struct bcm2835_config *cfg;
+	uint32 result;
+	void *mailbox_buffer_orig, *mailbox_buffer;
+
+	if (!(mailbox_buffer_orig = kmalloc(MAILBOX_BUFFER_SIZE))) {
+		return -1;
+	}
+
+	/* Round mailbox buffer to multiple of 0x10 because the low 4 bits of
+	the mailbox are used to send the channel, and therefore can't hold the low 4
+	bits of the address */
+	if ((uint32)mailbox_buffer_orig & 0xf)
+		mailbox_buffer = (void *)((uint32)mailbox_buffer_orig & ~0xf) + 0x10;
+	else
+		mailbox_buffer = mailbox_buffer_orig;
+
+	cfg = (struct bcm2835_config *)mailbox_buffer;
+	cfg->width = FB_WIDTH;
+	cfg->height = FB_HEIGHT;
+	cfg->vwidth = FB_WIDTH;
+	cfg->vheight = FB_HEIGHT;
+	cfg->pitch = 0;
+	cfg->color_depth = color_depth;
+	cfg->xoffset = 0;
+	cfg->yoffset = 0;
+	cfg->fb_base_addr = 0;
+	cfg->size = 0;
+
+	mailbox_write(MBOX_FB, (uint32)cfg);
+	result = mailbox_read(MBOX_FB);
+
+	if (result || !cfg->fb_base_addr) {
+		print("Error: did not request a proper framebuffer\n");
+		return -1;
+	}
+
+	f->device = &bcm2835_fb_device;
+	f->device->fbaddr = (void*)cfg->fb_base_addr;
+	f->width = cfg->width;
+	f->device->pixelwidth = cfg->width;
+	f->height = cfg->height;
+	f->device->pixelheight = cfg->height;
+
+	f->color_depth = color_depth;
+	f->device->color_depth = color_depth;
+
+	return 0;
+}

devices/kernel.mk

@@ -6,7 +6,9 @@ include $(BASEDIR)/header.mk
 OBJS_$(d) := $(d)/pl011.o \
 	$(d)/pl110.o \
 	$(d)/pl111.o \
-	$(d)/pi_mini_uart.o
+	$(d)/pi_mini_uart.o \
+	$(d)/bcm2835_mailbox.o \
+	$(d)/bcm2835_videocore.o
 
 KOBJS += $(OBJS_$(d))
 

include/devices/bcm2835_mailbox.h

@@ -0,0 +1,38 @@
+/*
+    Copyright (C) 2012, Aaron Lindsay <aaron@aclindsay.com>
+
+    This file is part of Aedrix.
+
+    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.
+
+    This program is distributed in the hope that it will be useful,
+    but WITHOUT ANY WARRANTY; without even the implied warranty of
+    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+    GNU General Public License for more details.
+
+    You should have received a copy of the GNU General Public License along
+    with this program; if not, write to the Free Software Foundation, Inc.,
+    51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
+ */
+
+#ifndef BCM2835_MAILBOX_H
+#define BCM2835_MAILBOX_H
+
+#include <types.h>
+
+/* BCM2835 Mailbox Channels */
+#define MBOX_PM		0	//Power management interface
+#define MBOX_FB		1	//Framebuffer
+#define MBOX_VUART	2	//Virtual UART
+#define MBOX_YCHIQ	3	//VCHIQ interface
+#define MBOX_LEDS	4	//LEDs interface
+#define MBOX_BUTTONS	5	//Buttons interface
+#define MBOX_TOUCHSCRN	6	//Touch screen interface
+
+uint32 mailbox_read(uint32 channel);
+void mailbox_write(uint32 channel, uint32 data);
+
+#endif /* BCM2835_MAILBOX_H */

include/devices/bcm2835_videocore.h

@@ -0,0 +1,28 @@
+/*
+    Copyright (C) 2012, Aaron Lindsay <aaron@aclindsay.com>
+
+    This file is part of Aedrix.
+
+    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.
+
+    This program is distributed in the hope that it will be useful,
+    but WITHOUT ANY WARRANTY; without even the implied warranty of
+    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+    GNU General Public License for more details.
+
+    You should have received a copy of the GNU General Public License along
+    with this program; if not, write to the Free Software Foundation, Inc.,
+    51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
+ */
+
+#include <framebuffer.h>
+
+#ifndef BCM2835_VIDEOCORE_H
+#define BCM2835_VIDEOCORE_H
+
+int bcm2835_videocore_init(struct fb *f, unsigned int color_depth);
+
+#endif /* BCM2835_VIDEOCORE_H */

kernel/start_kernel.c

@@ -25,7 +25,7 @@
 #include <print.h>
 #include <devices/pi_mini_uart.h>
 
-#include <devices/pl111.h>
+#include <devices/bcm2835_videocore.h>
 #include <framebuffer.h>
 #include <console.h>
 
@@ -33,10 +33,10 @@ struct fb myfb;
 
 void video(void) {
 	unsigned int x, y;
-	pl111_init(&myfb, 24);
+	bcm2835_videocore_init(&myfb, 16);
-	x = 0, y = 0;
+
-	for (y=0; y<480; y++)
+	for (y = 0; y < myfb.height; y++)
-		for (x=0; x<640; x++)
+		for (x = 0; x < myfb.width; x++)
 			fb_write_pixel(&myfb, x, y, 0x3f, 0x0, 0x6f);
 
 	console_init(&myfb);