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authorDaniel Baumann <daniel.baumann@progress-linux.org>2024-04-07 18:49:45 +0000
committerDaniel Baumann <daniel.baumann@progress-linux.org>2024-04-07 18:49:45 +0000
commit2c3c1048746a4622d8c89a29670120dc8fab93c4 (patch)
tree848558de17fb3008cdf4d861b01ac7781903ce39 /arch/sh/kernel/sh_bios.c
parentInitial commit. (diff)
downloadlinux-2c3c1048746a4622d8c89a29670120dc8fab93c4.tar.xz
linux-2c3c1048746a4622d8c89a29670120dc8fab93c4.zip
Adding upstream version 6.1.76.upstream/6.1.76
Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>
Diffstat (limited to 'arch/sh/kernel/sh_bios.c')
-rw-r--r--arch/sh/kernel/sh_bios.c169
1 files changed, 169 insertions, 0 deletions
diff --git a/arch/sh/kernel/sh_bios.c b/arch/sh/kernel/sh_bios.c
new file mode 100644
index 000000000..250dbdf3f
--- /dev/null
+++ b/arch/sh/kernel/sh_bios.c
@@ -0,0 +1,169 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * C interface for trapping into the standard LinuxSH BIOS.
+ *
+ * Copyright (C) 2000 Greg Banks, Mitch Davis
+ * Copyright (C) 1999, 2000 Niibe Yutaka
+ * Copyright (C) 2002 M. R. Brown
+ * Copyright (C) 2004 - 2010 Paul Mundt
+ */
+#include <linux/module.h>
+#include <linux/console.h>
+#include <linux/tty.h>
+#include <linux/init.h>
+#include <linux/io.h>
+#include <linux/delay.h>
+#include <asm/sh_bios.h>
+
+#define BIOS_CALL_CONSOLE_WRITE 0
+#define BIOS_CALL_ETH_NODE_ADDR 10
+#define BIOS_CALL_SHUTDOWN 11
+#define BIOS_CALL_GDB_DETACH 0xff
+
+void *gdb_vbr_vector = NULL;
+
+static inline long sh_bios_call(long func, long arg0, long arg1, long arg2,
+ long arg3)
+{
+ register long r0 __asm__("r0") = func;
+ register long r4 __asm__("r4") = arg0;
+ register long r5 __asm__("r5") = arg1;
+ register long r6 __asm__("r6") = arg2;
+ register long r7 __asm__("r7") = arg3;
+
+ if (!gdb_vbr_vector)
+ return -ENOSYS;
+
+ __asm__ __volatile__("trapa #0x3f":"=z"(r0)
+ :"0"(r0), "r"(r4), "r"(r5), "r"(r6), "r"(r7)
+ :"memory");
+ return r0;
+}
+
+void sh_bios_console_write(const char *buf, unsigned int len)
+{
+ sh_bios_call(BIOS_CALL_CONSOLE_WRITE, (long)buf, (long)len, 0, 0);
+}
+
+void sh_bios_gdb_detach(void)
+{
+ sh_bios_call(BIOS_CALL_GDB_DETACH, 0, 0, 0, 0);
+}
+EXPORT_SYMBOL_GPL(sh_bios_gdb_detach);
+
+void sh_bios_get_node_addr(unsigned char *node_addr)
+{
+ sh_bios_call(BIOS_CALL_ETH_NODE_ADDR, 0, (long)node_addr, 0, 0);
+}
+EXPORT_SYMBOL_GPL(sh_bios_get_node_addr);
+
+void sh_bios_shutdown(unsigned int how)
+{
+ sh_bios_call(BIOS_CALL_SHUTDOWN, how, 0, 0, 0);
+}
+
+/*
+ * Read the old value of the VBR register to initialise the vector
+ * through which debug and BIOS traps are delegated by the Linux trap
+ * handler.
+ */
+void sh_bios_vbr_init(void)
+{
+ unsigned long vbr;
+
+ if (unlikely(gdb_vbr_vector))
+ return;
+
+ __asm__ __volatile__ ("stc vbr, %0" : "=r" (vbr));
+
+ if (vbr) {
+ gdb_vbr_vector = (void *)(vbr + 0x100);
+ printk(KERN_NOTICE "Setting GDB trap vector to %p\n",
+ gdb_vbr_vector);
+ } else
+ printk(KERN_NOTICE "SH-BIOS not detected\n");
+}
+
+/**
+ * sh_bios_vbr_reload - Re-load the system VBR from the BIOS vector.
+ *
+ * This can be used by save/restore code to reinitialize the system VBR
+ * from the fixed BIOS VBR. A no-op if no BIOS VBR is known.
+ */
+void sh_bios_vbr_reload(void)
+{
+ if (gdb_vbr_vector)
+ __asm__ __volatile__ (
+ "ldc %0, vbr"
+ :
+ : "r" (((unsigned long) gdb_vbr_vector) - 0x100)
+ : "memory"
+ );
+}
+
+#ifdef CONFIG_EARLY_PRINTK
+/*
+ * Print a string through the BIOS
+ */
+static void sh_console_write(struct console *co, const char *s,
+ unsigned count)
+{
+ sh_bios_console_write(s, count);
+}
+
+/*
+ * Setup initial baud/bits/parity. We do two things here:
+ * - construct a cflag setting for the first rs_open()
+ * - initialize the serial port
+ * Return non-zero if we didn't find a serial port.
+ */
+static int __init sh_console_setup(struct console *co, char *options)
+{
+ int cflag = CREAD | HUPCL | CLOCAL;
+
+ /*
+ * Now construct a cflag setting.
+ * TODO: this is a totally bogus cflag, as we have
+ * no idea what serial settings the BIOS is using, or
+ * even if its using the serial port at all.
+ */
+ cflag |= B115200 | CS8 | /*no parity*/0;
+
+ co->cflag = cflag;
+
+ return 0;
+}
+
+static struct console bios_console = {
+ .name = "bios",
+ .write = sh_console_write,
+ .setup = sh_console_setup,
+ .flags = CON_PRINTBUFFER,
+ .index = -1,
+};
+
+static int __init setup_early_printk(char *buf)
+{
+ int keep_early = 0;
+
+ if (!buf)
+ return 0;
+
+ if (strstr(buf, "keep"))
+ keep_early = 1;
+
+ if (!strncmp(buf, "bios", 4))
+ early_console = &bios_console;
+
+ if (likely(early_console)) {
+ if (keep_early)
+ early_console->flags &= ~CON_BOOT;
+ else
+ early_console->flags |= CON_BOOT;
+ register_console(early_console);
+ }
+
+ return 0;
+}
+early_param("earlyprintk", setup_early_printk);
+#endif