[librm] Discard argument as part of return from prot_call()

Signed-off-by: Michael Brown <mcb30@ipxe.org>

src/arch/i386/interface/syslinux/comboot_call.c

@@ -663,7 +663,7 @@ void hook_comboot_interrupts ( ) {
 		              "pushl %0\n\t"
 		              "pushw %%cs\n\t"
 		              "call prot_call\n\t"
-		              "addw $4, %%sp\n\t"
+			      "clc\n\t"
 			      "call patch_cf\n\t"
 		              "iret\n\t" )
 		          : : "i" ( int20 ) );
@@ -675,7 +675,7 @@ void hook_comboot_interrupts ( ) {
 		              "pushl %0\n\t"
 		              "pushw %%cs\n\t"
 		              "call prot_call\n\t"
-		              "addw $4, %%sp\n\t"
+			      "clc\n\t"
 			      "call patch_cf\n\t"
 		              "iret\n\t" )
 		          : : "i" ( int21 ) );
@@ -687,7 +687,7 @@ void hook_comboot_interrupts ( ) {
 		              "pushl %0\n\t"
 		              "pushw %%cs\n\t"
 		              "call prot_call\n\t"
-		              "addw $4, %%sp\n\t"
+			      "clc\n\t"
 			      "call patch_cf\n\t"
 		              "iret\n\t" )
 		          : : "i" ( int22) );

src/arch/x86/core/dumpregs.c

@@ -9,7 +9,6 @@ void __asmcall _dump_regs ( struct i386_all_regs *ix86 ) {
 			      "pushl $_dump_regs\n\t"
 			      "pushw %%cs\n\t"
 			      "call prot_call\n\t"
-			      "addr32 leal 4(%%esp), %%esp\n\t"
 			      "ret\n\t" ) : : );
 
 	printf ( "EAX=%08x EBX=%08x ECX=%08x EDX=%08x\n"

src/arch/x86/interface/pcbios/bios_console.c

@@ -536,7 +536,6 @@ static void bios_inject_startup ( void ) {
 			      "pushl %0\n\t"
 			      "pushw %%cs\n\t"
 			      "call prot_call\n\t"
-			      "addw $4, %%sp\n\t"
 			      "\n1:\n\t"
 			      "popfw\n\t"
 			      "ljmp *%%cs:int16_vector\n\t" )

src/arch/x86/interface/pxe/pxe_entry.S

@@ -123,7 +123,6 @@ pxenv_entry:
 	pushl	$pxe_api_call
 	pushw	%cs
 	call	prot_call
-	addl	$4, %esp
 	lret
 	.size	pxenv_entry, . - pxenv_entry
 

src/arch/x86/prefix/dskprefix.S

@@ -373,7 +373,6 @@ start_runtime:
 	pushl	$main
 	pushw	%cs
 	call	prot_call
-	popl	%ecx /* discard */
 
 	/* Uninstall iPXE */
 	call	uninstall

src/arch/x86/prefix/exeprefix.S

@@ -151,7 +151,6 @@ _exe_start:
 	pushl	$main
 	pushw	%cs
 	call	prot_call
-	popl	%ecx /* discard */
 
 	/* Uninstall iPXE */
 	call	uninstall

src/arch/x86/prefix/hdprefix.S

@@ -102,7 +102,6 @@ start_image:
 	pushl	$main
 	pushw	%cs
 	call	prot_call
-	popl	%ecx /* discard */
 
 	/* Uninstall iPXE */
 	call	uninstall

src/arch/x86/prefix/libprefix.S

@@ -880,7 +880,6 @@ payload_death_message:
 	movw	%ax, (prot_call_vector+2)
 	pushl	$relocate
 	lcall	*prot_call_vector
-	popl	%edx /* discard */
 
 	/* Copy code to new location */
 	progress "  copy\n"

src/arch/x86/prefix/lkrnprefix.S

@@ -200,7 +200,6 @@ no_cmd_line:
 	pushl	$main
 	pushw	%cs
 	call	prot_call
-	popl	%ecx /* discard */
 
 	/* Uninstall iPXE */
 	call	uninstall

src/arch/x86/prefix/nbiprefix.S

@@ -69,7 +69,6 @@ _nbi_start:
 	pushl	$main
 	pushw	%cs
 	call	prot_call
-	popl	%ecx /* discard */
 
 	/* Uninstall iPXE */
 	call	uninstall

src/arch/x86/prefix/pxeprefix.S

@@ -823,7 +823,6 @@ run_ipxe:
 	pushl	$main
 	pushw	%cs
 	call	prot_call
-	popl	%ecx /* discard */
 
 	/* Uninstall iPXE */
 	call	uninstall

src/arch/x86/prefix/romprefix.S

@@ -807,7 +807,6 @@ exec:	/* Set %ds = %cs */
 	pushl	$main
 	pushw	%cs
 	call	prot_call
-	popl	%eax /* discard */
 
 	/* Set up flat real mode for return to BIOS */
 	call	flatten_real_mode

src/arch/x86/prefix/undiloader.S

@@ -41,9 +41,7 @@ undiloader:
 	pushw	%ax
 	pushw	$prot_call
 	lret
-1:	popw	%bx	/* discard */
+1:	/* Restore registers and return */
-	popw	%bx	/* discard */
-	/* Restore registers and return */
 	popw	%bx
 	popw	%es
 	popw	%ds

src/arch/x86/transitions/librm.S

@@ -134,7 +134,6 @@ init_librm:
 	pushl	$init_idt
 	pushw	%cs
 	call	prot_call
-	popl	%eax /* discard */
 
 	/* Restore registers */
 	negl	%edi
@@ -385,8 +384,8 @@ rm_gdtr:
  *
  * Example usage:
  *	pushl	$pxe_api_call
+ *	pushw	%cs
  *	call	prot_call
- *	addw	$4, %sp
  * to call in to the C function
  *      void pxe_api_call ( struct i386_all_regs *ix86 );
  ****************************************************************************
@@ -455,7 +454,7 @@ pc_rmode:
 	 */
 	addr32 movl -20(%esp), %esp
 	popfl
-	lret
+	lret	$4
 
 /****************************************************************************
  * real_call (protected-mode near call, 32-bit virtual return address)
@@ -554,7 +553,6 @@ flatten_real_mode:
 	pushl	$flatten_dummy
 	pushw	%cs
 	call	prot_call
-	addw	$4, %sp
 	/* Restore GDT */
 	movb	$0x00, real_cs + 6
 	movb	$0x00, real_ds + 6

src/arch/x86/transitions/librm_test.c

@@ -108,7 +108,6 @@ static void librm_test_exec ( void ) {
 						   "pushl %k3\n\t"
 						   "pushw %%cs\n\t"
 						   "call prot_call\n\t"
-						   "addw $4, %%sp\n\t"
 						   "rdtsc\n\t" )
 				       : "=a" ( stopped ), "=d" ( discard_d ),
 					 "=R" ( started )