[gPXE-devel] mainline commit to master: [comboot] Propagate carry flag from COMBOOT API

[git at etherboot.org]

In the Main gPXE repository, branch master has been updated.
      adds  4c61f2a [comboot] Propagate carry flag from COMBOOT API
      from  79d9b28 [uri] Special case NULL in churi()

Summary of changes:
 src/arch/i386/core/patch_cf.S                   |   38 +++++++++++++++++++++++
 src/arch/i386/firmware/pcbios/e820mangler.S     |   12 -------
 src/arch/i386/interface/syslinux/comboot_call.c |    3 ++
 3 files changed, 41 insertions(+), 12 deletions(-)
 create mode 100644 src/arch/i386/core/patch_cf.S


- Log -----------------------------------------------------------------
commit 4c61f2a6f430349aef9a3bed5243c30bb9a74873
Author: Stefan Hajnoczi <stefanha at gmail.com>
Date:   Sat May 8 11:49:09 2010 +0100

    [comboot] Propagate carry flag from COMBOOT API
    
    COMBOOT API calls set the carry flag on failure.  This was not being
    propagated because the COMBOOT interrupt handler used iret to return
    with EFLAGS restored from the stack.  This patch propagates CF before
    returning from the interrupt.
    
    Reported-by: Geoff Lywood <glywood at vmware.com>
    Signed-off-by: Stefan Hajnoczi <stefanha at gmail.com>
    Signed-off-by: Marty Connor <mdc at etherboot.org>

diff --git a/src/arch/i386/core/patch_cf.S b/src/arch/i386/core/patch_cf.S
new file mode 100644
index 0000000..97a62f4
--- /dev/null
+++ b/src/arch/i386/core/patch_cf.S
@@ -0,0 +1,38 @@
+/*
+ * Copyright (C) 2009 H. Peter Anvin <hpa at zytor.com>
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public License
+ * as published by the Free Software Foundation; either version 2
+ * of the License, or (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software
+ * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301, USA.
+ */
+
+FILE_LICENCE ( GPL2_OR_LATER )
+
+	.text
+	.arch i386
+	.code16
+
+/****************************************************************************
+ * Set/clear CF on the stack as appropriate, assumes stack is as it should
+ * be immediately before IRET
+ ****************************************************************************
+ */
+	.section ".text16", "ax", @progbits
+	.globl patch_cf
+patch_cf:
+	pushw	%bp
+	movw	%sp, %bp
+	setc	8(%bp)	/* Set/reset CF; clears PF, AF, ZF, SF */
+	popw	%bp
+	ret
+	.size patch_cf, . - patch_cf
diff --git a/src/arch/i386/firmware/pcbios/e820mangler.S b/src/arch/i386/firmware/pcbios/e820mangler.S
index 99ca519..eeed51f 100644
--- a/src/arch/i386/firmware/pcbios/e820mangler.S
+++ b/src/arch/i386/firmware/pcbios/e820mangler.S
@@ -493,18 +493,6 @@ get_mangled_e820:
 	.size get_mangled_e820, . - get_mangled_e820
 
 /****************************************************************************
- * Set/clear CF on the stack as appropriate, assumes stack is as it should
- * be immediately before IRET
- ****************************************************************************
- */
-patch_cf:
-	pushw	%bp
-	movw	%sp, %bp
-	setc	8(%bp)	/* Set/reset CF; clears PF, AF, ZF, SF */
-	popw	%bp
-	ret
-
-/****************************************************************************
  * INT 15,e820 handler
  ****************************************************************************
  */
diff --git a/src/arch/i386/interface/syslinux/comboot_call.c b/src/arch/i386/interface/syslinux/comboot_call.c
index 51a1b6d..dd94d8b 100644
--- a/src/arch/i386/interface/syslinux/comboot_call.c
+++ b/src/arch/i386/interface/syslinux/comboot_call.c
@@ -669,6 +669,7 @@ void hook_comboot_interrupts ( ) {
 		              "pushw %%cs\n\t"
 		              "call prot_call\n\t"
 		              "addw $4, %%sp\n\t"
+			      "call patch_cf\n\t"
 		              "iret\n\t" )
 		          : : "i" ( int20 ) );
 
@@ -681,6 +682,7 @@ void hook_comboot_interrupts ( ) {
 		              "pushw %%cs\n\t"
 		              "call prot_call\n\t"
 		              "addw $4, %%sp\n\t"
+			      "call patch_cf\n\t"
 		              "iret\n\t" )
 		          : : "i" ( int21 ) );
 
@@ -693,6 +695,7 @@ void hook_comboot_interrupts ( ) {
 		              "pushw %%cs\n\t"
 		              "call prot_call\n\t"
 		              "addw $4, %%sp\n\t"
+			      "call patch_cf\n\t"
 		              "iret\n\t" )
 		          : : "i" ( int22) );
 
-----------------------------------------------------------------------


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