Move atags support to be ARM arch-specific

arch/arm/include/atags.h

@@ -0,0 +1,68 @@
+/*
+    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 ATAGS_H
+#define ATAGS_H
+
+#include <types.h>
+
+#define ATAG_NONE	0x00000000
+#define ATAG_CORE	0x54410001
+#define ATAG_MEM	0x54410002
+#define ATAG_VIDEOTEXT	0x54410003
+#define ATAG_RAMDISK	0x54410004
+#define ATAG_INITRD2	0x54420005
+#define ATAG_SERIAL	0x54410006
+#define ATAG_REVISION	0x54410007
+#define ATAG_VIDEOLFB	0x54410008
+#define ATAG_CMDLINE	0x54410009
+
+struct atag_core {
+	uint32 flags;		/* bit 0 = read-only */
+	uint32 pagesize;	/* systems page size (usually 4k) */
+	uint32 rootdev;		/* root device number */
+};
+
+struct atag_mem {
+	uint32 size;	/* size of the area */
+	arch_uint_ptr start;	/* physical start address */
+};
+
+struct atag {
+	uint32 size; /* Size of tag in words (includes entire struct) */
+	uint32 tag;
+	union {
+		struct atag_core	core;
+		struct atag_mem		mem;
+//		struct atag_videotext	videotext;
+//		struct atag_ramdisk	ramdisk;
+//		struct atag_initrd2	initrd2;
+//		struct atag_serialnr	serialnr;
+//		struct atag_revision	revision;
+//		struct atag_videolfb	videolfb;
+//		struct atag_cmdline	cmdline;
+	} data;
+};
+
+#define atags_first_mem_region(atag) _atags_mem_region(atag, 1)
+#define atags_next_mem_region(atag) _atags_mem_region(atag, 0)
+int _atags_mem_region(struct atag **mem_header, int initialize);
+
+#endif /* ATAGS_H */

arch/arm/kernel/atags.c

@@ -0,0 +1,80 @@
+/*
+    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 <atags.h>
+#include <mmu.h>
+
+extern arch_uint_ptr atags_ptr;
+
+int atag_valid(struct atag *a) {
+	switch (a->tag) {
+		case ATAG_NONE:
+			return a->size == 2;
+		case ATAG_CORE:
+			return a->size == 2 || a->size == 5;
+		case ATAG_MEM:
+		case ATAG_INITRD2:
+		case ATAG_SERIAL:
+			return a->size == 4;
+		case ATAG_VIDEOTEXT:
+		case ATAG_RAMDISK:
+			return a->size == 5;
+		case ATAG_REVISION:
+			return a->size == 3;
+		case ATAG_VIDEOLFB:
+			return a->size == 8;
+		case ATAG_CMDLINE:
+			return a->size >= 3;
+		default:
+			return 0;
+	}
+}
+
+int _atags_mem_region(struct atag **mem_header, int initialize) {
+	if (initialize)
+		*mem_header = (struct atag *)atags_ptr;
+	else
+		*mem_header = (struct atag *)((uint32 *)*mem_header + (*mem_header)->size);
+
+	while (atag_valid(*mem_header) && (*mem_header)->tag != ATAG_NONE && (*mem_header)->tag != ATAG_MEM) {
+		*mem_header = (struct atag *)((uint32 *)*mem_header + (*mem_header)->size);
+	}
+
+	if (!atag_valid(*mem_header) || (*mem_header)->tag == ATAG_NONE)
+		return -1;
+	return 0;
+}
+
+int detect_memory() {
+	struct atag *atags;
+	char *lower, *upper;
+
+	if (atags_first_mem_region(&atags)) {
+		return -1;
+	}
+
+	do {
+		lower = (char *)atags->data.mem.start;
+		upper = lower + atags->data.mem.size - 1;
+		declare_memory_region(lower, upper);
+	} while (!atags_next_mem_region(&atags));
+
+	return 0;
+}

arch/arm/kernel/kernel.mk

@@ -3,7 +3,8 @@ SUBDIRS :=
 
 include $(BASEDIR)/header.mk
 
-OBJS_$(d) := $(d)/mmu.o
+OBJS_$(d) := $(d)/atags.o \
+	$(d)/mmu.o
 
 KOBJS += $(OBJS_$(d))