From 1c8eb8bad791fe9d01d0d4ab77882db634fa933d Mon Sep 17 00:00:00 2001
From: rofl0r <retnyg@gmx.net>
Date: Fri, 9 Nov 2012 23:36:55 +0100
Subject: PPC port cleaned up, static linking works well now.

---
 src/thread/powerpc/clone.s | 83 ++++++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 83 insertions(+)
 create mode 100644 src/thread/powerpc/clone.s

(limited to 'src/thread/powerpc/clone.s')

diff --git a/src/thread/powerpc/clone.s b/src/thread/powerpc/clone.s
new file mode 100644
index 00000000..cea69e99
--- /dev/null
+++ b/src/thread/powerpc/clone.s
@@ -0,0 +1,83 @@
+.text
+.global __clone
+.type __clone, %function
+__clone:
+# int clone(fn, stack, flags, arg, ptid, tls, ctid)
+#            a  b       c     d     e    f    g
+#            3  4       5     6     7    8    9
+# pseudo C code:
+# tid = syscall(SYS_clone,c,b,e,f,g);
+# if (!tid) syscall(SYS_exit, a(d));
+# return tid;
+
+# SYS_clone = 120
+# SYS_exit = 1
+
+# in order that the child can find the start func and its arg, we need to store it into
+# non-volative regs. to do so, we have to store those 2 regs into our stackframe, so
+# we can restore them later.
+stw 30, -4(1)
+stw 31, -8(1)
+subi 1, 1, 16 
+
+# save r3 (func) into r30, and r6(arg) into r31
+mr 30, 3
+mr 31, 6
+
+#move c into first arg
+mr 3, 5
+#mr 4, 4
+mr 5, 7
+mr 6, 8
+mr 7, 9
+
+# move syscall number into r0    
+li 0, 120
+
+sc
+
+# check for syscall error
+#this code should be more efficient, but it borks
+#bns+ 1f # jump to label 1 if no summary overflow.
+#else
+#neg 3, 3 #negate the result (errno)
+#b 2f # jump to epilogue
+
+# this error check code at least does not spoil the clone call.
+#mfcr    0                      # Check for an error
+#rlwinm  4, 0, 0, 3, 3        # by checking for bit 28.
+#cmplwi  0, 4, 0               # It is an error if non-zero.
+#beq     0, 1f                  # Jump if not an error.
+#neg     3, 3                  # Negate the error number.
+#b       2f # jump to epilogue
+1:
+# compare sc result with 0
+cmpwi cr7, 3, 0
+
+# if not 0, jump to end
+bne cr7, 2f
+
+#else: we're the child
+#call funcptr
+# move arg (d) into r3
+mr 3, 31
+#move r30 (funcptr) into CTR reg
+mtctr 30
+# call CTR reg
+bctrl
+# mov SYS_exit into r0 (the exit param is already in r3)
+li 0, 1
+sc
+
+2:
+
+# restore stack
+addi 1, 1, 16
+lwz 30, -4(1)
+lwz 31, -8(1)
+
+blr
+
+
+
+
-- 
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