[U-Boot,v5] x86: use EFI calling convention for efi_main on x86_64

Message ID ee027e3fe97ea517e9b935608ff3a440d815327d.1528907477.git.ivan.gorinov@intel.com
State Accepted
Delegated to: Bin Meng
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Series
  • [U-Boot,v5] x86: use EFI calling convention for efi_main on x86_64
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Commit Message

Ivan Gorinov June 14, 2018, 12:27 a.m.
UEFI specifies the calling convention used in Microsoft compilers;
first arguments of a function are passed in (%rcx, %rdx, %r8, %r9).

All other compilers use System V ABI by default, passing first integer
arguments of a function in (%rdi, %rsi, %rdx, %rcx, %r8, %r9).

These ABI also specify different sets of registers that must be preserved
across function calls (callee-saved).

GCC allows using the Microsoft calling convention by adding the ms_abi
attribute to a function declaration.

Current EFI implementation in U-Boot specifies EFIAPI for efi_main()
in the test apps but uses default calling convention in lib/efi.

Save efi_main() arguments in the startup code on x86_64;
use EFI calling convention for _relocate() on x86_64;
consistently use EFI calling convention for efi_main() everywhere.

Signed-off-by: Ivan Gorinov <ivan.gorinov@intel.com>
---
 arch/x86/lib/crt0_x86_64_efi.S | 24 +++++++++++++-----------
 lib/efi/efi_app.c              |  3 ++-
 lib/efi/efi_stub.c             |  3 ++-
 3 files changed, 17 insertions(+), 13 deletions(-)

Comments

Alexander Graf June 14, 2018, 8:33 a.m. | #1
On 06/14/2018 02:27 AM, Ivan Gorinov wrote:
> UEFI specifies the calling convention used in Microsoft compilers;
> first arguments of a function are passed in (%rcx, %rdx, %r8, %r9).
>
> All other compilers use System V ABI by default, passing first integer
> arguments of a function in (%rdi, %rsi, %rdx, %rcx, %r8, %r9).
>
> These ABI also specify different sets of registers that must be preserved
> across function calls (callee-saved).
>
> GCC allows using the Microsoft calling convention by adding the ms_abi
> attribute to a function declaration.
>
> Current EFI implementation in U-Boot specifies EFIAPI for efi_main()
> in the test apps but uses default calling convention in lib/efi.
>
> Save efi_main() arguments in the startup code on x86_64;
> use EFI calling convention for _relocate() on x86_64;
> consistently use EFI calling convention for efi_main() everywhere.
>
> Signed-off-by: Ivan Gorinov <ivan.gorinov@intel.com>

Reviewed-by: Alexander Graf <agraf@suse.de>

This patch should go via Bin's tree.


Alex
Bin Meng June 15, 2018, 10:13 a.m. | #2
On Thu, Jun 14, 2018 at 8:27 AM, Ivan Gorinov <ivan.gorinov@intel.com> wrote:
> UEFI specifies the calling convention used in Microsoft compilers;
> first arguments of a function are passed in (%rcx, %rdx, %r8, %r9).
>
> All other compilers use System V ABI by default, passing first integer
> arguments of a function in (%rdi, %rsi, %rdx, %rcx, %r8, %r9).
>
> These ABI also specify different sets of registers that must be preserved
> across function calls (callee-saved).
>
> GCC allows using the Microsoft calling convention by adding the ms_abi
> attribute to a function declaration.
>
> Current EFI implementation in U-Boot specifies EFIAPI for efi_main()
> in the test apps but uses default calling convention in lib/efi.
>
> Save efi_main() arguments in the startup code on x86_64;
> use EFI calling convention for _relocate() on x86_64;
> consistently use EFI calling convention for efi_main() everywhere.
>
> Signed-off-by: Ivan Gorinov <ivan.gorinov@intel.com>
> ---
>  arch/x86/lib/crt0_x86_64_efi.S | 24 +++++++++++++-----------
>  lib/efi/efi_app.c              |  3 ++-
>  lib/efi/efi_stub.c             |  3 ++-
>  3 files changed, 17 insertions(+), 13 deletions(-)
>

Reviewed-by: Bin Meng <bmeng.cn@gmail.com>
Tested-by: Bin Meng <bmeng.cn@gmail.com>
Bin Meng June 15, 2018, 10:14 a.m. | #3
On Fri, Jun 15, 2018 at 6:13 PM, Bin Meng <bmeng.cn@gmail.com> wrote:
> On Thu, Jun 14, 2018 at 8:27 AM, Ivan Gorinov <ivan.gorinov@intel.com> wrote:
>> UEFI specifies the calling convention used in Microsoft compilers;
>> first arguments of a function are passed in (%rcx, %rdx, %r8, %r9).
>>
>> All other compilers use System V ABI by default, passing first integer
>> arguments of a function in (%rdi, %rsi, %rdx, %rcx, %r8, %r9).
>>
>> These ABI also specify different sets of registers that must be preserved
>> across function calls (callee-saved).
>>
>> GCC allows using the Microsoft calling convention by adding the ms_abi
>> attribute to a function declaration.
>>
>> Current EFI implementation in U-Boot specifies EFIAPI for efi_main()
>> in the test apps but uses default calling convention in lib/efi.
>>
>> Save efi_main() arguments in the startup code on x86_64;
>> use EFI calling convention for _relocate() on x86_64;
>> consistently use EFI calling convention for efi_main() everywhere.
>>
>> Signed-off-by: Ivan Gorinov <ivan.gorinov@intel.com>
>> ---
>>  arch/x86/lib/crt0_x86_64_efi.S | 24 +++++++++++++-----------
>>  lib/efi/efi_app.c              |  3 ++-
>>  lib/efi/efi_stub.c             |  3 ++-
>>  3 files changed, 17 insertions(+), 13 deletions(-)
>>
>
> Reviewed-by: Bin Meng <bmeng.cn@gmail.com>
> Tested-by: Bin Meng <bmeng.cn@gmail.com>

applied to u-boot-x86, thanks!

Patch

diff --git a/arch/x86/lib/crt0_x86_64_efi.S b/arch/x86/lib/crt0_x86_64_efi.S
index 989799f..8a25ceb 100644
--- a/arch/x86/lib/crt0_x86_64_efi.S
+++ b/arch/x86/lib/crt0_x86_64_efi.S
@@ -3,7 +3,7 @@ 
  * crt0-efi-x86_64.S - x86_64 EFI startup code.
  * Copyright (C) 1999 Hewlett-Packard Co.
  * Contributed by David Mosberger <davidm@hpl.hp.com>.
- * Copyright (C) 2005 Intel Co.
+ * Copyright (C) 2005 Intel Corporation
  * Contributed by Fenghua Yu <fenghua.yu@intel.com>.
  *
  * All rights reserved.
@@ -14,26 +14,28 @@ 
 	.globl _start
 _start:
 	subq $8, %rsp
+
 	pushq %rcx
 	pushq %rdx
 
-0:
-	lea image_base(%rip), %rdi
-	lea _DYNAMIC(%rip), %rsi
+	mov %rcx, %r8
+	mov %rdx, %r9
+
+	lea image_base(%rip), %rcx
+	lea _DYNAMIC(%rip), %rdx
 
-	popq %rcx
-	popq %rdx
-	pushq %rcx
-	pushq %rdx
 	call _relocate
 
-	popq %rdi
-	popq %rsi
+	popq %rdx
+	popq %rcx
+
+	testq %rax, %rax
+	jnz .exit
 
 	call efi_main
+.exit:
 	addq $8, %rsp
 
-.exit:
 	ret
 
 	/*
diff --git a/lib/efi/efi_app.c b/lib/efi/efi_app.c
index c828093..3eb8eeb 100644
--- a/lib/efi/efi_app.c
+++ b/lib/efi/efi_app.c
@@ -96,7 +96,8 @@  static void free_memory(struct efi_priv *priv)
  * U-Boot. If it returns, EFI will continue. Another way to get back to EFI
  * is via reset_cpu().
  */
-efi_status_t efi_main(efi_handle_t image, struct efi_system_table *sys_table)
+efi_status_t EFIAPI efi_main(efi_handle_t image,
+			     struct efi_system_table *sys_table)
 {
 	struct efi_priv local_priv, *priv = &local_priv;
 	efi_status_t ret;
diff --git a/lib/efi/efi_stub.c b/lib/efi/efi_stub.c
index 3138739..399d16b 100644
--- a/lib/efi/efi_stub.c
+++ b/lib/efi/efi_stub.c
@@ -268,7 +268,8 @@  static void add_entry_addr(struct efi_priv *priv, enum efi_entry_t type,
  * This function is called by our EFI start-up code. It handles running
  * U-Boot. If it returns, EFI will continue.
  */
-efi_status_t efi_main(efi_handle_t image, struct efi_system_table *sys_table)
+efi_status_t EFIAPI efi_main(efi_handle_t image,
+			     struct efi_system_table *sys_table)
 {
 	struct efi_priv local_priv, *priv = &local_priv;
 	struct efi_boot_services *boot = sys_table->boottime;