kernel/aarch64: Add 'board_info' structure

Introduce a 'board_info' structure as well as an md_get_board() routine
to get information about the host

Signed-off-by: Ian Moffett <ian@osmora.org>

2 files changed, 62 insertions, 0 deletions

diff --git a/sys/arch/aarch64/aarch64/machdep.c b/sys/arch/aarch64/aarch64/machdep.c
index 33d7c42..9a96cbb 100644
--- a/sys/arch/aarch64/aarch64/machdep.c
+++ b/sys/arch/aarch64/aarch64/machdep.c
@@ -31,6 +31,7 @@
 #include <sys/panic.h>
 #include <machine/cpu.h>
 #include <machine/sync.h>
+#include <machine/board.h>
 
 struct cpu_info g_bsp_ci = {0};
 
@@ -98,3 +99,13 @@ cpu_startup(struct cpu_info *ci)
     __ASMV("msr tpidr_el1, %0" :: "r" (ci));
     md_cpu_init();
 }
+
+void
+md_get_board(struct board_info *res)
+{
+    uint64_t midr_el1;
+
+    __ASMV("mrs %0, midr_el1" : "=r" (midr_el1));
+    res->partno = (midr_el1 >> 4) & 0xFFF;
+    res->implementer = (midr_el1 >> 24) & 0xFF;
+}
diff --git a/sys/include/arch/aarch64/board.h b/sys/include/arch/aarch64/board.h
new file mode 100644
index 0000000..bba421f
--- /dev/null
+++ b/sys/include/arch/aarch64/board.h
@@ -0,0 +1,51 @@
+/*
+ * Copyright (c) 2023-2025 Ian Marco Moffett and the Osmora Team.
+ * All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions are met:
+ *
+ * 1. Redistributions of source code must retain the above copyright notice,
+ *    this list of conditions and the following disclaimer.
+ * 2. Redistributions in binary form must reproduce the above copyright
+ *    notice, this list of conditions and the following disclaimer in the
+ *    documentation and/or other materials provided with the distribution.
+ * 3. Neither the name of Hyra nor the names of its
+ *    contributors may be used to endorse or promote products derived from
+ *    this software without specific prior written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
+ * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+ * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
+ * ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE
+ * LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
+ * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
+ * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
+ * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
+ * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
+ * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
+ * POSSIBILITY OF SUCH DAMAGE.
+ */
+
+#ifndef _MACHINE_BOARD_H_
+#define _MACHINE_BOARD_H_
+
+/* Board implementer */
+#define BOARD_ARM_LIMITED   0x41    /* ARM Limited */
+#define BOARD_BROADCOM      0x42    /* Broadcom corp */
+#define BOARD_CAVIUM        0x43    /* Calvium Inc */
+#define BOARD_DIGITAL_EQUIP 0x44    /* Digital Equipment Corporation */
+#define BOARD_FUJITSU       0x46    /* Fujitsu Ltd */
+
+/*
+ * Board information, contains a part number
+ * and an implementer number.
+ */
+struct board_info {
+    uint8_t implementer;
+    uint16_t partno : 12;
+};
+
+void md_get_board(struct board_info *res);
+
+#endif  /* !_MACHINE_BOARD_H_ */