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-rw-r--r--src/arch/x86/Makefile.inc1
-rw-r--r--src/arch/x86/bootblock_crt0.S55
2 files changed, 56 insertions, 0 deletions
diff --git a/src/arch/x86/Makefile.inc b/src/arch/x86/Makefile.inc
index 2942cae3fb..21084d3fd8 100644
--- a/src/arch/x86/Makefile.inc
+++ b/src/arch/x86/Makefile.inc
@@ -112,6 +112,7 @@ $(call src-to-obj,bootblock,$(dir)/id.S): $(obj)/build.h
ifeq ($(CONFIG_C_ENVIRONMENT_BOOTBLOCK),y)
+bootblock-y += bootblock_crt0.S
bootblock-y += memlayout.ld
ifeq ($(CONFIG_ARCH_BOOTBLOCK_X86_32),y)
diff --git a/src/arch/x86/bootblock_crt0.S b/src/arch/x86/bootblock_crt0.S
new file mode 100644
index 0000000000..926cda08a7
--- /dev/null
+++ b/src/arch/x86/bootblock_crt0.S
@@ -0,0 +1,55 @@
+/*
+ * This is the modern bootblock. It is used by platforms which select
+ * C_ENVIRONMENT_BOOTBLOCK, and it prepares the system for C environment runtime
+ * setup. The actual setup is done by hardware-specific code.
+ *
+ * It provides a bootflow similar to other architectures, and thus is considered
+ * to be the modern approach.
+ *
+ * This file is part of the coreboot project.
+ *
+ * Copyright (C) 2015 Alexandru Gagniuc <mr.nuke.me@gmail.com>
+ *
+ * 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; either version 2 of the License, or
+ * (at your option) any later version.
+ */
+
+#define CR0_MP (1 << 1)
+#define CR0_EM (1 << 2)
+
+#define CR4_OSFXSR (1 << 9)
+#define CR4_OSXMMEXCPT (1 << 10)
+
+/*
+ * Include the old code for reset vector and protected mode entry. That code has
+ * withstood the test of time.
+ */
+#include <arch/x86/prologue.inc>
+#include <cpu/x86/16bit/entry16.inc>
+#include <cpu/x86/16bit/reset16.inc>
+#include <cpu/x86/32bit/entry32.inc>
+
+
+bootblock_protected_mode_entry:
+ /* Save BIST result */
+ movd %eax, %mm0
+ /* Save an early timestamp */
+ rdtsc
+ movd %eax, %mm1
+ movd %edx, %mm2
+
+#if !IS_ENABLED(CONFIG_SSE)
+enable_sse:
+ mov %cr0, %eax
+ and $~CR0_EM, %ax /* Clear coprocessor emulation CR0.EM */
+ or $CR0_MP, %ax /* Set coprocessor monitoring CR0.MP */
+ mov %eax, %cr0
+ mov %cr4, %eax
+ or $(CR4_OSFXSR | CR4_OSXMMEXCPT), %ax
+ mov %eax, %cr4
+#endif /* IS_ENABLED(CONFIG_SSE) */
+
+ /* We're done. Now it's up to platform-specific code */
+ jmp bootblock_pre_c_entry