libpayload: Add x86_64 (64-bit) support

This patch introduces x86_64 (64-bit) support to the payload, building
upon the existing x86 (32-bit) architecture. Files necessary for 64-bit
compilation are now guarded by the `CONFIG_LP_ARCH_X86_64` Kconfig
option.

BUG=b:242829490
TEST=Able to verify all valid combinations between coreboot and
payload with this patch.

Payload Entry Point Behavior with below code.

+----------------+--------------------+----------------------------+
| LP_ARCH_X86_64 | Payload Entry Mode | Description                |
+----------------+--------------------+----------------------------+
| No             | 32-bit             | Direct protected mode init |
+----------------+--------------------+----------------------------+
| Yes            | 32-bit             | Protected to long mode     |
+----------------+--------------------+----------------------------+
| Yes            | 64-bit             | Long mode initialization   |
+----------------+--------------------+----------------------------+

Change-Id: I69fda47bedf1a14807b1515c4aed6e3a1d5b8585
Signed-off-by: Subrata Banik <subratabanik@google.com>
Reviewed-on: https://review.coreboot.org/c/coreboot/+/81968
Reviewed-by: Julius Werner <jwerner@chromium.org>
Tested-by: build bot (Jenkins) <no-reply@coreboot.org>

1 files changed, 54 insertions, 0 deletions

diff --git a/payloads/libpayload/arch/x86/exec.c b/payloads/libpayload/arch/x86/exec.c
new file mode 100644
index 0000000000..06a5ed2bcd
--- /dev/null
+++ b/payloads/libpayload/arch/x86/exec.c
@@ -0,0 +1,54 @@
+/*
+ *
+ * Copyright (C) 2008 Advanced Micro Devices, Inc.
+ *
+ * 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. The name of the author may not be used to endorse or promote products
+ *    derived from this software without specific prior written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE AUTHOR 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 AUTHOR 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.
+ */
+
+#include <libpayload-config.h>
+#include <libpayload.h>
+
+#if CONFIG(LP_ARCH_X86_32)
+extern void i386_do_exec(long addr, int argc, char **argv, int *ret);
+#else
+#error "exec does not currently support x86_64."
+#endif
+
+/**
+ * Execute code in memory.
+ *
+ * @param addr TODO
+ * @param argc TODO
+ * @param argv TODO
+ * @return Return the return value from the entry point.
+ */
+int exec(long addr, int argc, char **argv)
+{
+	int val = -1;
+
+#if CONFIG(LP_ARCH_X86_32)
+	i386_do_exec(addr, argc, argv, &val);
+#endif
+	return val;
+}