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authorLinus Torvalds <torvalds@linux-foundation.org>2026-08-19 10:09:22 -0700
committerLinus Torvalds <torvalds@linux-foundation.org>2026-08-19 10:09:22 -0700
commitf4cdf7ca9a1fdcca413157df19753f388a5a224e (patch)
tree60a31895b2446cd7fa27514e8c2843534a0de0da /arch/x86/boot/tty.c
downloadlinux-stable-f4cdf7ca9a1fdcca413157df19753f388a5a224e.tar.gz
linux-stable-f4cdf7ca9a1fdcca413157df19753f388a5a224e.zip
Merge tag 'media/v7.3-1' of git://git.kernel.org/pub/scm/linux/kernel/git/mchehab/linux-mediagrafted
Pull media updates from Mauro Carvalho Chehab: - v4l2-core: added ISP statistics support and per-block validation - v4l2-core: Allow unknown HDR10 white point and luminance - New camera sensors: Sony IMX678 and IMX471m, Himax HM1092 IR sensor - New codec: Milos: VPU v2.0 codec support - isp driver: gained support for Dreamchip RPPX1 ISP framework - vsp1 driver: gained support for RZ/T2H and RZ/N2H - Novalake driver: gained CVS support for new NVL hardware - dvb-core: fix feed leak on failed DMX_ADD_PID - several driver fixes, cleanups and minor improvements * tag 'media/v7.3-1' of git://git.kernel.org/pub/scm/linux/kernel/git/mchehab/linux-media: (308 commits) media: ipu-bridge: check all DMI entries when overriding sensor rotation media: v4l2-async: avoid deleting unlinked ASC entry on link error media: rzg2l-cru: Align bytesperline to hardware DMA stride requirement media: intel/ipu6: fix async notifier cleanup leak on parse error media: staging/ipu7: fix async notifier UAF on probe error path media: amd: isp4: fix self-deadlock in isp4sd_pwron_and_init() error path media: amd: isp4: release partial allocations in isp4if_alloc_fw_gpumem() media: rcar-isp: Fix VSPX reference leaks media: rcar-isp: Release ISPCORE resources media: i2c: imx415: Release runtime PM reference on VBLANK error media: i2c: imx415: Return test pattern write errors media: renesas: vsp1: Declare index variables in for loop statement media: renesas: vsp1: Make reset control optional to support platforms without a reset line media: dt-bindings: media: renesas,vsp1: Document RZ/T2H and RZ/N2H SoCs media: dt-bindings: media: renesas,fcp: Document RZ/T2H and RZ/N2H SoCs media: nxp: imx8-isi: Add additional 32-bit RGB format support media: nxp: imx8-isi: Add 16-bit raw Bayer format support media: nxp: imx8-isi: Implement per-stream reference counting for multiplexed streams media: nxp: imx8-isi: Use BIT_ULL() for 64-bit stream masks media: nxp: imx8-isi: Correct color map between V4L2 and ISI ...
Diffstat (limited to 'arch/x86/boot/tty.c')
-rw-r--r--arch/x86/boot/tty.c137
1 files changed, 137 insertions, 0 deletions
diff --git a/arch/x86/boot/tty.c b/arch/x86/boot/tty.c
new file mode 100644
index 000000000..f7eb976b0
--- /dev/null
+++ b/arch/x86/boot/tty.c
@@ -0,0 +1,137 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/* -*- linux-c -*- ------------------------------------------------------- *
+ *
+ * Copyright (C) 1991, 1992 Linus Torvalds
+ * Copyright 2007 rPath, Inc. - All Rights Reserved
+ * Copyright 2009 Intel Corporation; author H. Peter Anvin
+ *
+ * ----------------------------------------------------------------------- */
+
+/*
+ * Very simple screen and serial I/O
+ */
+
+#include "boot.h"
+
+int early_serial_base;
+
+#define XMTRDY 0x20
+
+#define TXR 0 /* Transmit register (WRITE) */
+#define LSR 5 /* Line Status */
+
+/*
+ * These functions are in .inittext so they can be used to signal
+ * error during initialization.
+ */
+
+static void __section(".inittext") serial_putchar(int ch)
+{
+ unsigned timeout = 0xffff;
+
+ while ((inb(early_serial_base + LSR) & XMTRDY) == 0 && --timeout)
+ cpu_relax();
+
+ outb(ch, early_serial_base + TXR);
+}
+
+static void __section(".inittext") bios_putchar(int ch)
+{
+ struct biosregs ireg;
+
+ initregs(&ireg);
+ ireg.bx = 0x0007;
+ ireg.cx = 0x0001;
+ ireg.ah = 0x0e;
+ ireg.al = ch;
+ intcall(0x10, &ireg, NULL);
+}
+
+void __section(".inittext") putchar(int ch)
+{
+ if (ch == '\n')
+ putchar('\r'); /* \n -> \r\n */
+
+ bios_putchar(ch);
+
+ if (early_serial_base != 0)
+ serial_putchar(ch);
+}
+
+void __section(".inittext") puts(const char *str)
+{
+ while (*str)
+ putchar(*str++);
+}
+
+/*
+ * Read the CMOS clock through the BIOS, and return the
+ * seconds in BCD.
+ */
+
+static u8 gettime(void)
+{
+ struct biosregs ireg, oreg;
+
+ initregs(&ireg);
+ ireg.ah = 0x02;
+ intcall(0x1a, &ireg, &oreg);
+
+ return oreg.dh;
+}
+
+/*
+ * Read from the keyboard
+ */
+int getchar(void)
+{
+ struct biosregs ireg, oreg;
+
+ initregs(&ireg);
+ /* ireg.ah = 0x00; */
+ intcall(0x16, &ireg, &oreg);
+
+ return oreg.al;
+}
+
+static int kbd_pending(void)
+{
+ struct biosregs ireg, oreg;
+
+ initregs(&ireg);
+ ireg.ah = 0x01;
+ intcall(0x16, &ireg, &oreg);
+
+ return !(oreg.eflags & X86_EFLAGS_ZF);
+}
+
+void kbd_flush(void)
+{
+ for (;;) {
+ if (!kbd_pending())
+ break;
+ getchar();
+ }
+}
+
+int getchar_timeout(void)
+{
+ int cnt = 30;
+ int t0, t1;
+
+ t0 = gettime();
+
+ while (cnt) {
+ if (kbd_pending())
+ return getchar();
+
+ t1 = gettime();
+ if (t0 != t1) {
+ cnt--;
+ t0 = t1;
+ }
+ }
+
+ return 0; /* Timeout! */
+}
+