[comboot] Support COMBOOT in 64-bit builds

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

12 files changed, 179 insertions, 101 deletions

diff --git a/src/arch/i386/Makefile b/src/arch/i386/Makefile
index a5298604..fe3adc9c 100644
--- a/src/arch/i386/Makefile
+++ b/src/arch/i386/Makefile
@@ -83,9 +83,7 @@ endif
 # i386-specific directories containing source files
 #
 SRCDIRS		+= arch/i386/core
-SRCDIRS		+= arch/i386/image
 SRCDIRS		+= arch/i386/tests
-SRCDIRS		+= arch/i386/interface/syslinux
 
 # Include common x86 Makefile
 #
diff --git a/src/arch/x86/Makefile b/src/arch/x86/Makefile
index e933f4a4..368c29f6 100644
--- a/src/arch/x86/Makefile
+++ b/src/arch/x86/Makefile
@@ -16,6 +16,7 @@ SRCDIRS		+= arch/x86/interface/pxe
 SRCDIRS		+= arch/x86/interface/pxeparent
 SRCDIRS		+= arch/x86/interface/efi
 SRCDIRS		+= arch/x86/interface/vmware
+SRCDIRS		+= arch/x86/interface/syslinux
 SRCDIRS		+= arch/x86/prefix
 SRCDIRS		+= arch/x86/hci/commands
 SRCDIRS		+= arch/x86/drivers/xen
diff --git a/src/arch/i386/image/com32.c b/src/arch/x86/image/com32.c
index ff64fd1a..01665287 100644
--- a/src/arch/i386/image/com32.c
+++ b/src/arch/x86/image/com32.c
@@ -76,8 +76,6 @@ static int com32_exec_loop ( struct image *image ) {
 
 		assert ( avail_mem_top != 0 );
 
-		com32_external_esp = phys_to_virt ( avail_mem_top );
-
 		/* Hook COMBOOT API interrupts */
 		hook_comboot_interrupts();
 
@@ -88,34 +86,44 @@ static int com32_exec_loop ( struct image *image ) {
 		 */
 		unregister_image ( image );
 
-		__asm__ __volatile__ (
-			"movl %%esp, (com32_internal_esp)\n\t" /* Save internal virtual address space ESP */
-			"movl (com32_external_esp), %%esp\n\t" /* Switch to COM32 ESP (top of available memory) */
-			"call _virt_to_phys\n\t"               /* Switch to flat physical address space */
-			"sti\n\t"			       /* Enable interrupts */
-			"pushl %0\n\t"                         /* Pointer to CDECL helper function */
-			"pushl %1\n\t"                         /* Pointer to FAR call helper function */
-			"pushl %2\n\t"                         /* Size of low memory bounce buffer */
-			"pushl %3\n\t"                         /* Pointer to low memory bounce buffer */
-			"pushl %4\n\t"                         /* Pointer to INT call helper function */
-			"pushl %5\n\t"                         /* Pointer to the command line arguments */
-			"pushl $6\n\t"                         /* Number of additional arguments */
-			"call *%6\n\t"                         /* Execute image */
-			"cli\n\t"			       /* Disable interrupts */
-			"call _phys_to_virt\n\t"               /* Switch back to internal virtual address space */
-			"movl (com32_internal_esp), %%esp\n\t" /* Switch back to internal stack */
-		:
-		:
-			/* %0 */ "r" ( virt_to_phys ( com32_cfarcall_wrapper ) ),
-			/* %1 */ "r" ( virt_to_phys ( com32_farcall_wrapper ) ),
-			/* %2 */ "r" ( get_fbms() * 1024 - (COM32_BOUNCE_SEG << 4) ),
-			/* %3 */ "i" ( COM32_BOUNCE_SEG << 4 ),
-			/* %4 */ "r" ( virt_to_phys ( com32_intcall_wrapper ) ),
-			/* %5 */ "r" ( virt_to_phys ( image->cmdline ?
-						      image->cmdline : "" ) ),
-			/* %6 */ "r" ( COM32_START_PHYS )
-		:
-			"memory" );
+		__asm__ __volatile__ ( PHYS_CODE (
+			/* Preserve registers */
+			"pushal\n\t"
+			/* Preserve stack pointer */
+			"subl $4, %k0\n\t"
+			"movl %%esp, (%k0)\n\t"
+			/* Switch to COM32 stack */
+			"movl %k0, %%esp\n\t"
+			/* Enable interrupts */
+			"sti\n\t"
+			/* Construct stack frame */
+			"pushl %k1\n\t"
+			"pushl %k2\n\t"
+			"pushl %k3\n\t"
+			"pushl %k4\n\t"
+			"pushl %k5\n\t"
+			"pushl %k6\n\t"
+			"pushl $6\n\t"
+			/* Call COM32 entry point */
+			"movl %k7, %k0\n\t"
+			"call *%k0\n\t"
+			/* Disable interrupts */
+			"cli\n\t"
+			/* Restore stack pointer */
+			"movl 24(%%esp), %%esp\n\t"
+			/* Restore registers */
+			"popal\n\t" )
+			:
+			: "r" ( avail_mem_top ),
+			  "r" ( virt_to_phys ( com32_cfarcall_wrapper ) ),
+			  "r" ( virt_to_phys ( com32_farcall_wrapper ) ),
+			  "r" ( get_fbms() * 1024 - ( COM32_BOUNCE_SEG << 4 ) ),
+			  "i" ( COM32_BOUNCE_SEG << 4 ),
+			  "r" ( virt_to_phys ( com32_intcall_wrapper ) ),
+			  "r" ( virt_to_phys ( image->cmdline ?
+					       image->cmdline : "" ) ),
+			  "i" ( COM32_START_PHYS )
+			: "memory" );
 		DBGC ( image, "COM32 %p: returned\n", image );
 		break;
 
@@ -147,7 +155,7 @@ static int com32_exec_loop ( struct image *image ) {
 
 /**
  * Check image name extension
- * 
+ *
  * @v image		COM32 image
  * @ret rc		Return status code
  */
@@ -155,7 +163,7 @@ static int com32_identify ( struct image *image ) {
 	const char *ext;
 	static const uint8_t magic[] = { 0xB8, 0xFF, 0x4C, 0xCD, 0x21 };
 	uint8_t buf[5];
-	
+
 	if ( image->len >= 5 ) {
 		/* Check for magic number
 		 * mov eax,21cd4cffh
diff --git a/src/arch/i386/image/comboot.c b/src/arch/x86/image/comboot.c
index 20b5ae1e..9a847f0f 100644
--- a/src/arch/i386/image/comboot.c
+++ b/src/arch/x86/image/comboot.c
@@ -64,7 +64,7 @@ struct comboot_psp {
 
 /**
  * Copy command line to PSP
- * 
+ *
  * @v image		COMBOOT image
  */
 static void comboot_copy_cmdline ( struct image * image, userptr_t seg_userptr ) {
@@ -97,7 +97,7 @@ static void comboot_copy_cmdline ( struct image * image, userptr_t seg_userptr )
 
 /**
  * Initialize PSP
- * 
+ *
  * @v image		COMBOOT image
  * @v seg_userptr	segment to initialize
  */
@@ -213,7 +213,7 @@ static int comboot_exec_loop ( struct image *image ) {
 
 /**
  * Check image name extension
- * 
+ *
  * @v image		COMBOOT image
  * @ret rc		Return status code
  */
@@ -254,7 +254,7 @@ static int comboot_prepare_segment ( struct image *image )
 	seg_userptr = real_to_user ( COMBOOT_PSP_SEG, 0 );
 
 	/* Allow etra 0x100 bytes before image for PSP */
-	filesz = image->len + 0x100; 
+	filesz = image->len + 0x100;
 
 	/* Ensure the entire 64k segment is free */
 	memsz = 0xFFFF;
@@ -289,7 +289,7 @@ static int comboot_probe ( struct image *image ) {
 
 	/* Check if this is a COMBOOT image */
 	if ( ( rc = comboot_identify ( image ) ) != 0 ) {
-		
+
 		return rc;
 	}
 
@@ -304,7 +304,7 @@ static int comboot_probe ( struct image *image ) {
  */
 static int comboot_exec ( struct image *image ) {
 	int rc;
-	
+
 	/* Sanity check for filesize */
 	if( image->len >= 0xFF00 ) {
 		DBGC( image, "COMBOOT %p: image too large\n",
diff --git a/src/arch/i386/include/comboot.h b/src/arch/x86/include/comboot.h
index 5cb1ba54..69c6ef02 100644
--- a/src/arch/i386/include/comboot.h
+++ b/src/arch/x86/include/comboot.h
@@ -29,7 +29,7 @@ FILE_LICENCE ( GPL2_OR_LATER );
 #define COMBOOT_FEATURE_LOCAL_BOOT (1 << 0)
 #define COMBOOT_FEATURE_IDLE_LOOP  (1 << 1)
 
-/** Maximum number of shuffle descriptors for 
+/** Maximum number of shuffle descriptors for
  * shuffle and boot functions
  * (INT 22h AX=0012h, 001Ah, 001Bh)
  */
@@ -102,7 +102,7 @@ typedef struct {
 extern void hook_comboot_interrupts ( );
 extern void unhook_comboot_interrupts ( );
 
-/* These are not the correct prototypes, but it doens't matter, 
+/* These are not the correct prototypes, but it doens't matter,
  * as we only ever get the address of these functions;
  * they are only called from COM32 code running in PHYS_CODE
  */
@@ -116,8 +116,6 @@ extern int comboot_resolv ( const char *name, struct in_addr *address );
 /* setjmp/longjmp context buffer used to return after loading an image */
 extern rmjmp_buf comboot_return;
 
-extern void *com32_external_esp;
-
 #define COMBOOT_EXIT 1
 #define COMBOOT_EXIT_RUN_KERNEL 2
 #define COMBOOT_EXIT_COMMAND 3
diff --git a/src/arch/i386/interface/syslinux/com32_call.c b/src/arch/x86/interface/syslinux/com32_call.c
index 75dcc238..19fdbaff 100644
--- a/src/arch/i386/interface/syslinux/com32_call.c
+++ b/src/arch/x86/interface/syslinux/com32_call.c
@@ -46,6 +46,9 @@ uint16_t __bss16 ( com32_saved_sp );
  */
 void __asmcall com32_intcall ( uint8_t interrupt, physaddr_t inregs_phys, physaddr_t outregs_phys ) {
 
+	DBGC ( &com32_regs, "COM32 INT%x in %#08lx out %#08lx\n",
+	       interrupt, inregs_phys, outregs_phys );
+
 	memcpy_user ( virt_to_user( &com32_regs ), 0,
 	              phys_to_user ( inregs_phys ), 0,
 	              sizeof(com32sys_t) );
@@ -76,7 +79,7 @@ void __asmcall com32_intcall ( uint8_t interrupt, physaddr_t inregs_phys, physad
 		            /* patch INT instruction */
 		            "pushw %%ax\n\t"
 		            "movb %%ss:(com32_int_vector), %%al\n\t"
-		            "movb %%al, %%cs:(com32_intcall_instr + 1)\n\t" 
+		            "movb %%al, %%cs:(com32_intcall_instr + 1)\n\t"
 		            /* perform a jump to avoid problems with cache
 		             * consistency in self-modifying code on some CPUs (486)
 		             */
@@ -106,7 +109,7 @@ void __asmcall com32_intcall ( uint8_t interrupt, physaddr_t inregs_phys, physad
 
 	if ( outregs_phys ) {
 		memcpy_user ( phys_to_user ( outregs_phys ), 0,
-		              virt_to_user( &com32_regs ), 0, 
+		              virt_to_user( &com32_regs ), 0,
 		              sizeof(com32sys_t) );
 	}
 }
@@ -116,6 +119,9 @@ void __asmcall com32_intcall ( uint8_t interrupt, physaddr_t inregs_phys, physad
  */
 void __asmcall com32_farcall ( uint32_t proc, physaddr_t inregs_phys, physaddr_t outregs_phys ) {
 
+	DBGC ( &com32_regs, "COM32 farcall %04x:%04x in %#08lx out %#08lx\n",
+	       ( proc >> 16 ), ( proc & 0xffff ), inregs_phys, outregs_phys );
+
 	memcpy_user ( virt_to_user( &com32_regs ), 0,
 	              phys_to_user ( inregs_phys ), 0,
 	              sizeof(com32sys_t) );
@@ -165,7 +171,7 @@ void __asmcall com32_farcall ( uint32_t proc, physaddr_t inregs_phys, physaddr_t
 
 	if ( outregs_phys ) {
 		memcpy_user ( phys_to_user ( outregs_phys ), 0,
-		              virt_to_user( &com32_regs ), 0, 
+		              virt_to_user( &com32_regs ), 0,
 		              sizeof(com32sys_t) );
 	}
 }
@@ -176,13 +182,16 @@ void __asmcall com32_farcall ( uint32_t proc, physaddr_t inregs_phys, physaddr_t
 int __asmcall com32_cfarcall ( uint32_t proc, physaddr_t stack, size_t stacksz ) {
 	int32_t eax;
 
+	DBGC ( &com32_regs, "COM32 cfarcall %04x:%04x params %#08lx+%#zx\n",
+	       ( proc >> 16 ), ( proc & 0xffff ), stack, stacksz );
+
 	copy_user_to_rm_stack ( phys_to_user ( stack ), stacksz );
 	com32_farcall_proc = proc;
 
 	__asm__ __volatile__ (
 		REAL_CODE ( "lcall *%%ss:(com32_farcall_proc)\n\t" )
 		: "=a" (eax)
-		: 
+		:
 		: "ecx", "edx" );
 
 	remove_user_from_rm_stack ( 0, stacksz );
diff --git a/src/arch/i386/interface/syslinux/com32_wrapper.S b/src/arch/x86/interface/syslinux/com32_wrapper.S
index c9d1452b..d59a3392 100644
--- a/src/arch/i386/interface/syslinux/com32_wrapper.S
+++ b/src/arch/x86/interface/syslinux/com32_wrapper.S
@@ -19,79 +19,82 @@
 
 FILE_LICENCE ( GPL2_OR_LATER )
 
+#include "librm.h"
+
 	.text
-	.arch i386
-	.code32
 
+	.code32
 	.globl com32_farcall_wrapper
 com32_farcall_wrapper:
+	movl	$VIRTUAL(com32_farcall), %eax
+	jmp	com32_wrapper
 
-	movl $com32_farcall, %eax
-	jmp com32_wrapper
-
-
+	.code32
 	.globl com32_cfarcall_wrapper
 com32_cfarcall_wrapper:
+	movl	$VIRTUAL(com32_cfarcall), %eax
+	jmp	com32_wrapper
 
-	movl $com32_cfarcall, %eax
-	jmp com32_wrapper
-
-
+	.code32
 	.globl com32_intcall_wrapper
 com32_intcall_wrapper:
+	movl	$VIRTUAL(com32_intcall), %eax
+	/* fall through */
 
-	movl $com32_intcall, %eax
-	/*jmp com32_wrapper*/ /* fall through */
-
+	.code32
 com32_wrapper:
+
+	/* Disable interrupts */
 	cli
 
 	/* Switch to internal virtual address space */
-	call _phys_to_virt
-
-	mov %eax, (com32_helper_function)
+	call	_phys_to_virt
 
-	/* Save external COM32 stack pointer */
-	movl %esp, (com32_external_esp)
+#ifdef __x86_64__
 
-	/* Copy arguments to caller-save registers */
-	movl 12(%esp), %eax
-	movl 8(%esp), %ecx
-	movl 4(%esp), %edx
+	.code64
 
-	/* Switch to internal stack */
-	movl (com32_internal_esp), %esp
+	/* Preserve registers which are callee-save for COM32 (i386 API) */
+	pushq	%rdi
+	pushq	%rsi
+	pushq	%rbp
 
-	/* Copy arguments to internal stack */
-	pushl %eax
-	pushl %ecx
-	pushl %edx
+	/* Extract parameters from stack */
+	movl	28(%rsp), %edi
+	movl	32(%rsp), %esi
+	movl	36(%rsp), %edx
 
-	call *(com32_helper_function)
+	/* Align stack pointer */
+	movq	%rsp, %rbp
+	andq	$~0x07, %rsp
 
-	/* Clean up stack */
-	addl $12, %esp
+	/* Call helper function */
+	movslq	%eax, %rax
+	call	*%rax
 
-	/* Save internal stack pointer and restore external stack pointer */
-	movl %esp, (com32_internal_esp)
-	movl (com32_external_esp), %esp
+	/* Restore stack pointer */
+	movq	%rbp, %rsp
 
-	/* Switch to external flat physical address space */
-	call _virt_to_phys
-
-	sti
-	ret
+	/* Restore registers */
+	popq	%rbp
+	popq	%rsi
+	popq	%rdi
 
+#else /* _x86_64 */
 
-	.data
+	/* Call helper function */
+	pushl	12(%esp)
+	pushl	12(%esp)
+	pushl	12(%esp)
+	call	*%eax
+	addl	$12, %esp
 
-/* Internal iPXE virtual address space %esp */
-.globl com32_internal_esp
-.lcomm com32_internal_esp, 4
+#endif /* _x86_64 */
 
-/* External flat physical address space %esp */
-.globl com32_external_esp
-.lcomm com32_external_esp, 4
+	/* Switch to external flat physical address space */
+	call	_virt_to_phys
+	.code32
 
-/* Function pointer of helper to call */
-.lcomm com32_helper_function, 4
+	/* Reenable interrupts and return */
+	sti
+	ret
diff --git a/src/arch/i386/interface/syslinux/comboot_call.c b/src/arch/x86/interface/syslinux/comboot_call.c
index 56597781..2f5c252c 100644
--- a/src/arch/i386/interface/syslinux/comboot_call.c
+++ b/src/arch/x86/interface/syslinux/comboot_call.c
@@ -489,7 +489,7 @@ static __asmcall void int22 ( struct i386_all_regs *ix86 ) {
 			struct in_addr addr;
 
 			copy_from_user ( hostname, hostname_u, 0, len + 1 );
-			
+
 			/* TODO:
 			 * "If the hostname does not contain a dot (.), the
 			 * local domain name is automatically appended."
@@ -519,7 +519,7 @@ static __asmcall void int22 ( struct i386_all_regs *ix86 ) {
 
 		/* Jump to real-mode entry point */
 		__asm__ __volatile__ (
-			REAL_CODE ( 
+			REAL_CODE (
 				"pushw %0\n\t"
 				"popw %%ds\n\t"
 				"pushl %1\n\t"
diff --git a/src/arch/i386/interface/syslinux/comboot_resolv.c b/src/arch/x86/interface/syslinux/comboot_resolv.c
index 03bbfd04..03bbfd04 100644
--- a/src/arch/i386/interface/syslinux/comboot_resolv.c
+++ b/src/arch/x86/interface/syslinux/comboot_resolv.c
diff --git a/src/arch/i386/tests/comboot/shuffle-simple.asm b/src/arch/x86/tests/comboot/shuffle-simple.asm
index 8ede8d09..fa574bd7 100644
--- a/src/arch/i386/tests/comboot/shuffle-simple.asm
+++ b/src/arch/x86/tests/comboot/shuffle-simple.asm
@@ -37,4 +37,3 @@ source:	dd 0
 	dd shuffle_len
 
 num_shuffle_descriptors equ 1
-
diff --git a/src/arch/i386/tests/comboot/version.asm b/src/arch/x86/tests/comboot/version.asm
index 01140423..01140423 100644
--- a/src/arch/i386/tests/comboot/version.asm
+++ b/src/arch/x86/tests/comboot/version.asm
diff --git a/src/arch/x86/transitions/librm.S b/src/arch/x86/transitions/librm.S
index 3a585a92..f633b352 100644
--- a/src/arch/x86/transitions/librm.S
+++ b/src/arch/x86/transitions/librm.S
@@ -567,9 +567,10 @@ phys_to_prot:
 	popl	%eax
 	ret
 
-	/* Expose as _phys_to_virt for use by COMBOOT */
+.if32	/* Expose as _phys_to_virt for use by COMBOOT, if applicable */
 	.globl	_phys_to_virt
 	.equ	_phys_to_virt, phys_to_prot
+.endif
 
 /****************************************************************************
  * prot_to_phys (protected-mode near call, 32-bit virtual return address)
@@ -615,9 +616,10 @@ prot_to_phys:
 	popl	%eax
 	ret
 
-	/* Expose as _virt_to_phys for use by COMBOOT */
+.if32	/* Expose as _virt_to_phys for use by COMBOOT, if applicable */
 	.globl	_virt_to_phys
 	.equ	_virt_to_phys, prot_to_phys
+.endif
 
 /****************************************************************************
  * intr_to_prot (protected-mode near call, 32-bit virtual return address)
@@ -1203,6 +1205,66 @@ phys_call:
 	ret	$( PHC_OFFSET_END - PHC_OFFSET_PARAMS )
 
 /****************************************************************************
+ * phys_to_long (protected-mode near call, 32-bit physical return address)
+ *
+ * Used by COMBOOT.
+ *
+ ****************************************************************************
+ */
+	.if64
+
+	.section ".text.phys_to_long", "ax", @progbits
+	.code32
+phys_to_long:
+
+	/* Switch to virtual addresses */
+	call	phys_to_prot
+
+	/* Convert to 32-bit virtual return address */
+	pushl	%eax
+	movl	VIRTUAL(virt_offset), %eax
+	subl	%eax, 4(%esp)
+	popl	%eax
+
+	/* Switch to long mode and return */
+	jmp	prot_to_long
+
+	/* Expose as _phys_to_virt for use by COMBOOT */
+	.globl  _phys_to_virt
+	.equ    _phys_to_virt, phys_to_long
+
+	.endif
+
+/****************************************************************************
+ * long_to_phys (long-mode near call, 64-bit virtual return address)
+ *
+ * Used by COMBOOT.
+ *
+ ****************************************************************************
+ */
+	.if64
+
+	.section ".text.long_to_phys", "ax", @progbits
+	.code64
+long_to_phys:
+
+	/* Switch to protected mode */
+	call	long_to_prot
+	.code32
+
+	/* Convert to 32-bit virtual return address */
+	popl	(%esp)
+
+	/* Switch to physical addresses and return */
+	jmp	prot_to_phys
+
+	/* Expose as _virt_to_phys for use by COMBOOT */
+	.globl  _virt_to_phys
+	.equ    _virt_to_phys, long_to_phys
+
+	.endif
+
+/****************************************************************************
  * flatten_real_mode (real-mode near call)
  *
  * Switch to flat real mode