From: John Tsiombikas <nuclear@member.fsf.org>
Date: Wed, 11 Nov 2020 21:58:08 +0000 (+0200)
Subject: video initialization seems to work, further testing needed
X-Git-Url: http://git.mutantstargoat.com/user/nuclear/?p=rpikern;a=commitdiff_plain;h=203b43a75a028e9238307bd6e73768eb8e942071

video initialization seems to work, further testing needed
---

diff --git a/Makefile b/Makefile
index 3b12438..ac7afa8 100644
--- a/Makefile
+++ b/Makefile
@@ -58,6 +58,5 @@ disasm: $(elf)
 	$(toolprefix)objdump -d $<
 
 .PHONY: install
-install: $(bin) $(elf)
+install: $(bin)
 	cp $(bin) /srv/tftp/$(bin)
-	cp $(elf) /srv/tftp/$(elf)
diff --git a/doc/notes.md b/doc/notes.md
new file mode 100644
index 0000000..0d4e804
--- /dev/null
+++ b/doc/notes.md
@@ -0,0 +1,18 @@
+Raspberry Pi2 notes
+===================
+The following is not all confirmed.
+
+Memory map
+----------
+RAM is mapped to 0, 40000000 (cache-coherent) and c0000000h (uncached) in VC
+space. In the ARM address space is mapped to 0(?).
+
+I/O base is at 7e000000 in VC address space (rpi1?), and mapped to different
+ranges for each model in ARM space.
+
+Memory map summary:
+ - load address: 8000h
+ - I/O base:
+   * rpi0/1: 20000000h
+   * rpi2/3: 3f000000h
+   * rpi4:   fe000000h
diff --git a/src/main.c b/src/main.c
index e204820..0c8bdf5 100644
--- a/src/main.c
+++ b/src/main.c
@@ -5,6 +5,7 @@
 #include <ctype.h>
 #include "asm.h"
 #include "serial.h"
+#include "video.h"
 
 void dbgled(int x);
 void exit(int x);
@@ -18,8 +19,11 @@ int main(void)
 	static int cmdend;
 
 	init_serial(115200);
-	ser_printstr("starting rpikern\n");
+	ser_printstr("Starting rpikern\n");
 
+	video_init();
+
+	ser_printstr("Going interactive\n");
 	for(;;) {
 		int c = ser_getchar();
 
diff --git a/src/mem.h b/src/mem.h
new file mode 100644
index 0000000..8285c05
--- /dev/null
+++ b/src/mem.h
@@ -0,0 +1,7 @@
+#ifndef MEM_H_
+#define MEM_H_
+
+#define MEM_BUS_COHERENT(addr)	(((uint32_t)addr) | 0x40000000)
+#define MEM_BUS_UNCACHED(addr)	(((uint32_t)addr) | 0xc0000000)
+
+#endif	/* MEM_H_ */
diff --git a/src/video.c b/src/video.c
new file mode 100644
index 0000000..33b740f
--- /dev/null
+++ b/src/video.c
@@ -0,0 +1,68 @@
+#include "config.h"
+#include <string.h>
+#include <stdint.h>
+#include "video.h"
+#include "serial.h"
+#include "mem.h"
+
+#define MBOX_READ_REG	(*(volatile uint32_t*)(IO_BASE | 0xb880))
+#define MBOX_POLL_REG	(*(volatile uint32_t*)(IO_BASE | 0xb890))
+#define MBOX_SENDER_REG	(*(volatile uint32_t*)(IO_BASE | 0xb894))
+#define MBOX_STATUS_REG	(*(volatile uint32_t*)(IO_BASE | 0xb898))
+#define MBOX_CFG_REG	(*(volatile uint32_t*)(IO_BASE | 0xb89c))
+#define MBOX_WRITE_REG	(*(volatile uint32_t*)(IO_BASE | 0xb8a0))
+
+#define MBOX_STAT_WRBUSY	0x80000000
+#define MBOX_STAT_RDBUSY	0x40000000
+
+struct vc_fbinfo {
+	uint32_t phys_width, phys_height;
+	uint32_t virt_width, virt_height;
+	uint32_t pitch;			/* filled by videocore */
+	uint32_t depth;
+	uint32_t x, y;
+	void *addr;		/* filled by videocore */
+	uint32_t size;	/* filled by videocore */
+};
+
+void mbox_write(int mbox, uint32_t msg);
+uint32_t mbox_read(int mbox);
+
+static struct vc_fbinfo fbinf __attribute__((aligned(16)));
+
+int video_init(void)
+{
+	memset(&fbinf, 0, sizeof fbinf);
+	fbinf.phys_width = fbinf.virt_width = 1024;
+	fbinf.phys_height = fbinf.virt_height = 600;
+	fbinf.depth = 32;
+	fbinf.x = fbinf.y = 0;
+
+	mbox_write(1, MEM_BUS_COHERENT(&fbinf));
+	if(mbox_read(1) != 0) {
+		ser_printstr("Failed to initialize display\n");
+		return -1;
+	}
+
+	ser_printstr("Video init successful\n");
+	memset(fbinf.addr, 0, fbinf.size);
+	return 0;
+}
+
+void mbox_write(int mbox, uint32_t msg)
+{
+	while(MBOX_STATUS_REG & MBOX_STAT_WRBUSY);
+	MBOX_WRITE_REG = (msg & 0xfffffff0) | mbox;
+}
+
+uint32_t mbox_read(int mbox)
+{
+	uint32_t msg;
+
+	do {
+		while(MBOX_STATUS_REG & MBOX_STAT_RDBUSY);
+		msg = MBOX_READ_REG;
+	} while((msg & 0xf) != mbox);
+
+	return msg & 0xfffffff0;
+}
diff --git a/src/video.h b/src/video.h
new file mode 100644
index 0000000..5c524b4
--- /dev/null
+++ b/src/video.h
@@ -0,0 +1,6 @@
+#ifndef VIDEO_H_
+#define VIDEO_H_
+
+int video_init(void);
+
+#endif	/* VIDEO_H_ */