Expose device(mbinfo) with read access to multiboot raw info

Message-ID: <20241027092828.3162279-1-damien@zamaudio.com>

1 files changed, 49 insertions, 0 deletions

diff --git a/i386/i386at/mbinfo.c b/i386/i386at/mbinfo.c
new file mode 100644
index 00000000..0722b8eb
--- /dev/null
+++ b/i386/i386at/mbinfo.c
@@ -0,0 +1,49 @@
+/*
+ * Copyright (c) 2024 Free Software Foundation, Inc.
+ *
+ * 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, see <http://www.gnu.org/licenses/>.
+ */
+
+#include <string.h>
+#include <i386at/mbinfo.h>
+#include <mach/vm_param.h>
+#include <vm/pmap.h>
+#include <device/ds_routines.h>
+
+static struct multiboot_raw_info mb_info;
+
+void
+mbinfo_register_boot_data(const struct multiboot_raw_info *mbi)
+{
+	mb_info = *mbi;
+}
+
+io_return_t
+mbinforead(dev_t dev, io_req_t ior)
+{
+	int err;
+
+	/* Check if IO_COUNT is valid */
+	if (ior->io_count > sizeof(struct multiboot_raw_info))
+	    return D_INVALID_SIZE;
+
+	err = device_read_alloc(ior, (vm_size_t)ior->io_count);
+	if (err != KERN_SUCCESS)
+	    return (err);
+
+	memcpy ((uint8_t *)ior->io_data, &mb_info, ior->io_count);
+
+	ior->io_residual = 0;
+	return (D_SUCCESS);
+}