Add a reference for Linux ARM ABI.
The Android NDK docs link to a ARM GNU/Linux Application Binary Interface
Supplement document. Also fix a type in trampoline-armv4.pl. The generic ARM
document is usually shortened AAPCS, not APCS.
I couldn't find a corresponding link for aarch64.
Change-Id: I6e5543f5c9e26955cd3945e9e7a5dcff27c2bd78
Reviewed-on: https://boringssl-review.googlesource.com/c/35064
Commit-Queue: David Benjamin <davidben@google.com>
Commit-Queue: Adam Langley <agl@google.com>
Reviewed-by: Adam Langley <agl@google.com>
diff --git a/crypto/test/abi_test.h b/crypto/test/abi_test.h
index 0d685ed..44547f8 100644
--- a/crypto/test/abi_test.h
+++ b/crypto/test/abi_test.h
@@ -109,14 +109,12 @@
// References:
// AAPCS: http://infocenter.arm.com/help/topic/com.arm.doc.ihi0042f/IHI0042F_aapcs.pdf
// iOS32: https://developer.apple.com/library/archive/documentation/Xcode/Conceptual/iPhoneOSABIReference/Articles/ARMv6FunctionCallingConventions.html
+// Linux: http://sourcery.mentor.com/sgpp/lite/arm/portal/kbattach142/arm_gnu_linux_%20abi.pdf
//
-// ARM specifies a common calling convention, except r9 is left to the
-// platform. Linux and iOS differ in handling of r9. iOS's behavior is defined
-// below. We found no clear reference for Linux but observed behavior from
-// LLVM. iOS 3+ treats r9 as caller-saved, while Linux treats it as
-// callee-saved. Most of our assembly treats it as callee-saved to be uniform,
-// but we match the platform to avoid false positives when testing
-// compiler-generated output.
+// ARM specifies a common calling convention, except r9 is left to the platform.
+// Linux treats r9 as callee-saved, while iOS 3+ treats it as caller-saved. Most
+// of our assembly treats it as callee-saved to be uniform, but we match the
+// platform to avoid false positives when testing compiler-generated output.
#define LOOP_CALLER_STATE_REGISTERS_PRE_R9() \
CALLER_STATE_REGISTER(uint64_t, d8) \
CALLER_STATE_REGISTER(uint64_t, d9) \
diff --git a/crypto/test/asm/trampoline-armv4.pl b/crypto/test/asm/trampoline-armv4.pl
index bfa67e4..30f510e 100755
--- a/crypto/test/asm/trampoline-armv4.pl
+++ b/crypto/test/asm/trampoline-armv4.pl
@@ -27,6 +27,7 @@
# AAPCS: http://infocenter.arm.com/help/topic/com.arm.doc.ihi0042f/IHI0042F_aapcs.pdf
# iOS ARMv6: https://developer.apple.com/library/archive/documentation/Xcode/Conceptual/iPhoneOSABIReference/Articles/ARMv6FunctionCallingConventions.html
# iOS ARMv7: https://developer.apple.com/library/archive/documentation/Xcode/Conceptual/iPhoneOSABIReference/Articles/ARMv7FunctionCallingConventions.html
+# Linux: http://sourcery.mentor.com/sgpp/lite/arm/portal/kbattach142/arm_gnu_linux_%20abi.pdf
use strict;
@@ -70,10 +71,10 @@
stmdb sp!, {r0-r11,lr}
@ Reserve stack space for six (10-4) stack parameters, plus an extra 4
- @ bytes to keep it 8-byte-aligned (see APCS, section 5.3).
+ @ bytes to keep it 8-byte-aligned (see AAPCS, section 5.3).
sub sp, sp, #28
- @ Every register in APCS is either non-volatile or a parameter (except
+ @ Every register in AAPCS is either non-volatile or a parameter (except
@ r9 on iOS), so this code, by the actual call, loses all its scratch
@ registers. First fill in stack parameters while there are registers
@ to spare.
