From: Alan Cox <alan@linux.intel.com>
Date: Sat, 25 Aug 2018 14:13:57 +0000 (+0100)
Subject: z80-thunked: More assorted fixes
X-Git-Url: https://git.ndcode.org/public/gitweb.cgi?a=commitdiff_plain;h=073e512683ad45c1d87594aee4733dfe889c6a2b;p=FUZIX.git

z80-thunked: More assorted fixes

We are now at the point some syscalls sort of work
---

diff --git a/Kernel/lowlevel-z80-thunked.s b/Kernel/lowlevel-z80-thunked.s
index b1317031..4e23ce1a 100644
--- a/Kernel/lowlevel-z80-thunked.s
+++ b/Kernel/lowlevel-z80-thunked.s
@@ -113,8 +113,8 @@ unix_syscall_entry:
 	ld (U_DATA__U_CALLNO),a	
 	ld (U_DATA__U_ARGN),bc
 	ld (U_DATA__U_ARGN1),de
-	ld (U_DATA__U_ARGN2),hl
-	ld (U_DATA__U_ARGN3),ix
+	ld (U_DATA__U_ARGN2),ix
+	ld (U_DATA__U_ARGN3),hl
 	; Stack the alternate registers
 	exx
 	push bc
@@ -157,7 +157,7 @@ syscall_return:
 	exx
 	; Return page for caller (may not be the page we can in on if we
 	; swapped
-	ld a,(U_DATA__U_PAGE2)
+	ld a,(U_DATA__U_PAGE+1)
 	ret
 signal_path:
 	ld h,a		; save signal number
@@ -233,6 +233,7 @@ intreti:di
 	ld a, (U_DATA__U_INSYS)
 	or a
 	jr nz, interrupt_kernel
+	call map_user_low
 intsig:
 	ld a,(U_DATA__U_CURSIG)
 	or a
@@ -241,8 +242,9 @@ intsig:
 no_sig:
 	xor a
 	ld e,a
-	ld a,(U_DATA__U_PAGE2)
+	ld a,(U_DATA__U_PAGE+1)
 intret:
+	ex af,af'
 	exx
 	pop iy
 	pop ix
diff --git a/Kernel/usermem_std-z80-thunked.s b/Kernel/usermem_std-z80-thunked.s
index 1d09734f..db83917c 100644
--- a/Kernel/usermem_std-z80-thunked.s
+++ b/Kernel/usermem_std-z80-thunked.s
@@ -197,6 +197,7 @@ __ugetc:
 	ld a,(U_DATA__U_PAGE)
 	jr z, ugetcl
 	ld a,(U_DATA__U_PAGE + 1)
+	res 7,h
 ugetcl:
 	call map_page_low
 	ld l,(hl)
@@ -211,26 +212,31 @@ __ugetw:
 	push bc
 	bit 7,h
 	jr z, ugetwl
+	; High page - no wrap possible
 	ld a,(U_DATA__U_PAGE + 1)
 	call map_page_low
 	res 7,h
 	ld a,(hl)
 	inc hl
 normal_wl:
+	; Get the high byte
 	ld h,(hl)
 	ld l,a
 	jp map_kernel_low
 ugetwl:
+	; Low page - we might be fetching 7FFF/8000
 	ld a,(U_DATA__U_PAGE)
 	call map_page_low
 	ld a,(hl)
 	inc hl
 	bit 7,h
-	jr z, normal_wl
+	jr z, normal_wl		; No split
+	; We fetched 7FFF/8000
 	ld l,a
+	ld a,(U_DATA__U_PAGE + 1)
+	call map_page_low
 	ld a,(0)		; Split can only mean one address
 	ld h,a
-	ld a,(U_DATA__U_PAGE + 1)
 	jp map_kernel_low
 
 __uputc:
@@ -244,6 +250,7 @@ __uputc:
 	ld a,(U_DATA__U_PAGE)
 	jr z, uputcl
 	ld a,(U_DATA__U_PAGE + 1)
+	res 7,h
 uputcl:
 	call map_page_low
 	ld (hl),e
@@ -274,6 +281,7 @@ uputwl:
 	bit 7,h
 	jr z, normal_pwl
 	ld a,(U_DATA__U_PAGE + 1)
+	call map_page_low
 	ld a,d
 	ld (0),a		; Split can only mean one address
 	jp map_kernel_low