1 files changed, 76 insertions, 0 deletions
diff --git a/src/arch/x86/cbmem.c b/src/arch/x86/cbmem.c
new file mode 100644
index 0000000..e279db9
--- /dev/null
+++ b/src/arch/x86/cbmem.c
@@ -0,0 +1,76 @@
+/*
+ * This file is part of the coreboot project.
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; version 2 of the License.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software
+ * Foundation, Inc.
+ */
+
+#include <stdlib.h>
+#include <console/console.h>
+#include <cbmem.h>
+#include <arch/acpi.h>
+
+#if IS_ENABLED(CONFIG_LATE_CBMEM_INIT)
+
+#if !defined(__PRE_RAM__)
+void __attribute__((weak)) backup_top_of_ram(uint64_t ramtop)
+{
+	/* Do nothing. Chipset may have implementation to save ramtop in NVRAM. */
+}
+
+static void *ramtop_pointer;
+
+void set_top_of_ram(uint64_t ramtop)
+{
+	backup_top_of_ram(ramtop);
+	ramtop_pointer = (void *)(uintptr_t)ramtop;
+}
+
+static inline void *saved_ramtop(void)
+{
+	return ramtop_pointer;
+}
+#else
+static inline void *saved_ramtop(void)
+{
+	return NULL;
+}
+#endif /* !__PRE_RAM__ */
+
+unsigned long __attribute__((weak)) get_top_of_ram(void)
+{
+	return 0;
+}
+
+void *cbmem_top(void)
+{
+	/* Top of cbmem is at lowest usable DRAM address below 4GiB. */
+	void *ptr = saved_ramtop();
+
+	if (ptr != NULL)
+		return ptr;
+
+	return (void *)get_top_of_ram();
+}
+
+#endif /* LATE_CBMEM_INIT */
+
+/* Something went wrong, our high memory area got wiped */
+void cbmem_fail_resume(void)
+{
+#if !defined(__PRE_RAM__) && IS_ENABLED(CONFIG_HAVE_ACPI_RESUME)
+	/* ACPI resume needs to be cleared in the fail-to-recover case, but that
+	 * condition is only handled during ramstage. */
+	acpi_fail_wakeup();
+#endif
+}