cmd/link: enable c-shared and c-archive mode on s390x
Adding s390x to the list of architectures that support c-shared and c-archive.
Required adding load-time initialization (via _rt0_s390x_linux_lib) and adding s390x
to the c-shared and c-archive tests.
Change-Id: I75883b2891c310fe8ce7f08c27b06895c074e123
Reviewed-on: https://go-review.googlesource.com/74910
Reviewed-by: Michael Munday <mike.munday@ibm.com>
diff --git a/src/runtime/asm_s390x.s b/src/runtime/asm_s390x.s
index 487ed62..6b71830 100644
--- a/src/runtime/asm_s390x.s
+++ b/src/runtime/asm_s390x.s
@@ -7,6 +7,83 @@
#include "funcdata.h"
#include "textflag.h"
+// _rt0_s390x_lib is common startup code for s390x systems when
+// using -buildmode=c-archive or -buildmode=c-shared. The linker will
+// arrange to invoke this function as a global constructor (for
+// c-archive) or when the shared library is loaded (for c-shared).
+// We expect argc and argv to be passed in the usual C ABI registers
+// R2 and R3.
+TEXT _rt0_s390x_lib(SB), NOSPLIT|NOFRAME, $0
+ STMG R6, R15, 48(R15)
+ MOVD R2, _rt0_s390x_lib_argc<>(SB)
+ MOVD R3, _rt0_s390x_lib_argv<>(SB)
+
+ // Save R6-R15 in the register save area of the calling function.
+ STMG R6, R15, 48(R15)
+
+ // Allocate 80 bytes on the stack.
+ MOVD $-80(R15), R15
+
+ // Save F8-F15 in our stack frame.
+ FMOVD F8, 16(R15)
+ FMOVD F9, 24(R15)
+ FMOVD F10, 32(R15)
+ FMOVD F11, 40(R15)
+ FMOVD F12, 48(R15)
+ FMOVD F13, 56(R15)
+ FMOVD F14, 64(R15)
+ FMOVD F15, 72(R15)
+
+ // Synchronous initialization.
+ MOVD $runtime·libpreinit(SB), R1
+ BL R1
+
+ // Create a new thread to finish Go runtime initialization.
+ MOVD _cgo_sys_thread_create(SB), R1
+ CMP R1, $0
+ BEQ nocgo
+ MOVD $_rt0_s390x_lib_go(SB), R2
+ MOVD $0, R3
+ BL R1
+ BR restore
+
+nocgo:
+ MOVD $0x800000, R1 // stacksize
+ MOVD R1, 0(R15)
+ MOVD $_rt0_s390x_lib_go(SB), R1
+ MOVD R1, 8(R15) // fn
+ MOVD $runtime·newosproc(SB), R1
+ BL R1
+
+restore:
+ // Restore F8-F15 from our stack frame.
+ FMOVD 16(R15), F8
+ FMOVD 24(R15), F9
+ FMOVD 32(R15), F10
+ FMOVD 40(R15), F11
+ FMOVD 48(R15), F12
+ FMOVD 56(R15), F13
+ FMOVD 64(R15), F14
+ FMOVD 72(R15), F15
+ MOVD $80(R15), R15
+
+ // Restore R6-R15.
+ LMG 48(R15), R6, R15
+ RET
+
+// _rt0_s390x_lib_go initializes the Go runtime.
+// This is started in a separate thread by _rt0_s390x_lib.
+TEXT _rt0_s390x_lib_go(SB), NOSPLIT|NOFRAME, $0
+ MOVD _rt0_s390x_lib_argc<>(SB), R2
+ MOVD _rt0_s390x_lib_argv<>(SB), R3
+ MOVD $runtime·rt0_go(SB), R1
+ BR R1
+
+DATA _rt0_s390x_lib_argc<>(SB)/8, $0
+GLOBL _rt0_s390x_lib_argc<>(SB), NOPTR, $8
+DATA _rt0_s90x_lib_argv<>(SB)/8, $0
+GLOBL _rt0_s390x_lib_argv<>(SB), NOPTR, $8
+
TEXT runtime·rt0_go(SB),NOSPLIT,$0
// R2 = argc; R3 = argv; R11 = temp; R13 = g; R15 = stack pointer
// C TLS base pointer in AR0:AR1
