arch/x86/boot: Jump to payload in protected mode

*   On ARCH_RAMSTAGE_X86_64 jump to the payload in protected mode.
*   Add a helper function to jump to arbitrary code in protected mode,
    similar to the real mode call handler.
*   Doesn't affect existing x86_32 code.
*   Add a macro to cast pointer to uint32_t that dies if it would overflow
    on conversion

Tested on QEMU Q35 using SeaBIOS as payload.
Tested on Lenovo T410 with additional x86_64 patches.

Change-Id: I6552ac30f1b6205e08e16d251328e01ce3fbfd14
Signed-off-by: Patrick Rudolph <siro@das-labor.org>
Reviewed-on: https://review.coreboot.org/c/coreboot/+/30118
Tested-by: build bot (Jenkins) <no-reply@coreboot.org>
Reviewed-by: Arthur Heymans <arthur@aheymans.xyz>

1 files changed, 11 insertions, 0 deletions

diff --git a/src/arch/x86/include/arch/boot/boot.h b/src/arch/x86/include/arch/boot/boot.h
index c73591579a..1ef927e0fb 100644
--- a/src/arch/x86/include/arch/boot/boot.h
+++ b/src/arch/x86/include/arch/boot/boot.h
@@ -7,4 +7,15 @@
 #define ELF_DATA	ELFDATA2LSB
 #define ELF_ARCH	EM_386
 
+#include <types.h>
+/*
+ * Jump to function in protected mode.
+ * @arg func_ptr           Function to jump to in protected mode
+ * @arg                    Argument to pass to called function
+ *
+ * @noreturn
+ */
+void protected_mode_jump(uint32_t func_ptr,
+			 uint32_t argument);
+
 #endif /* ASM_I386_BOOT_H */