v4.19.13 snapshot.
diff --git a/arch/x86/boot/apm.c b/arch/x86/boot/apm.c
new file mode 100644
index 0000000..ee27483
--- /dev/null
+++ b/arch/x86/boot/apm.c
@@ -0,0 +1,75 @@
+/* -*- linux-c -*- ------------------------------------------------------- *
+ *
+ * Copyright (C) 1991, 1992 Linus Torvalds
+ * Copyright 2007 rPath, Inc. - All Rights Reserved
+ * Copyright 2009 Intel Corporation; author H. Peter Anvin
+ *
+ * Original APM BIOS checking by Stephen Rothwell, May 1994
+ * (sfr@canb.auug.org.au)
+ *
+ * This file is part of the Linux kernel, and is made available under
+ * the terms of the GNU General Public License version 2.
+ *
+ * ----------------------------------------------------------------------- */
+
+/*
+ * Get APM BIOS information
+ */
+
+#include "boot.h"
+
+int query_apm_bios(void)
+{
+ struct biosregs ireg, oreg;
+
+ /* APM BIOS installation check */
+ initregs(&ireg);
+ ireg.ah = 0x53;
+ intcall(0x15, &ireg, &oreg);
+
+ if (oreg.flags & X86_EFLAGS_CF)
+ return -1; /* No APM BIOS */
+
+ if (oreg.bx != 0x504d) /* "PM" signature */
+ return -1;
+
+ if (!(oreg.cx & 0x02)) /* 32 bits supported? */
+ return -1;
+
+ /* Disconnect first, just in case */
+ ireg.al = 0x04;
+ intcall(0x15, &ireg, NULL);
+
+ /* 32-bit connect */
+ ireg.al = 0x03;
+ intcall(0x15, &ireg, &oreg);
+
+ boot_params.apm_bios_info.cseg = oreg.ax;
+ boot_params.apm_bios_info.offset = oreg.ebx;
+ boot_params.apm_bios_info.cseg_16 = oreg.cx;
+ boot_params.apm_bios_info.dseg = oreg.dx;
+ boot_params.apm_bios_info.cseg_len = oreg.si;
+ boot_params.apm_bios_info.cseg_16_len = oreg.hsi;
+ boot_params.apm_bios_info.dseg_len = oreg.di;
+
+ if (oreg.flags & X86_EFLAGS_CF)
+ return -1;
+
+ /* Redo the installation check as the 32-bit connect;
+ some BIOSes return different flags this way... */
+
+ ireg.al = 0x00;
+ intcall(0x15, &ireg, &oreg);
+
+ if ((oreg.eflags & X86_EFLAGS_CF) || oreg.bx != 0x504d) {
+ /* Failure with 32-bit connect, try to disconect and ignore */
+ ireg.al = 0x04;
+ intcall(0x15, &ireg, NULL);
+ return -1;
+ }
+
+ boot_params.apm_bios_info.version = oreg.ax;
+ boot_params.apm_bios_info.flags = oreg.cx;
+ return 0;
+}
+