From: Alan Cox <alan@linux.intel.com>
Date: Mon, 11 Feb 2019 01:47:51 +0000 (+0000)
Subject: 8080: switch to new ABI
X-Git-Url: https://git.ndcode.org/public/gitweb.cgi?a=commitdiff_plain;h=50b2460a29db37535e1064475ae61fd7bc647f1b;p=FUZIX.git

8080: switch to new ABI
---

diff --git a/Kernel/lowlevel-8080.s b/Kernel/lowlevel-8080.s
index c042e134..11d5ed31 100644
--- a/Kernel/lowlevel-8080.s
+++ b/Kernel/lowlevel-8080.s
@@ -56,14 +56,10 @@ signal_return:
 unix_syscall_entry:
 	di
 	push b		! Must preserve the frame pointer
-	push d		! will go away when we fix the ABI
 	lxi h,6		! Find arguments on stack frame
 
 	dad sp
-	mov a,m
 	sta U_DATA__U_CALLNO
-	inx h
-	inx h
 	! Oh for LDIR
 	! Unroll this for speed. Syscall arguments into constant locations
 	mov a,m
@@ -130,11 +126,12 @@ unix_return:
 	ora l
 	jz not_error
 	stc
+	! Carry and errno in HL as expected
 	jmp unix_pop
 not_error:
+	! Retval in HL as the Z80 kernel returns it
 	xchg
 unix_pop:
-	pop d
 	pop b
 	! ret must directly follow the ei
 	ei