Add a register-setting shuffle and boot for real mode; clean up headers.syslinux-3.40-pre14

- Add an API function to shuffle and boot which sets *all* RM registers;
- Move those structures to <syslinux/bootpm.h> and <syslinux/bootrm.h>

12 files changed, 272 insertions, 31 deletions

diff --git a/NEWS b/NEWS
index 78cd027b..39591367 100644
--- a/NEWS
+++ b/NEWS
@@ -12,9 +12,10 @@ Changes in 3.40:
 	  internationalization of menu messages.
 	* A new feature, TEXT HELP, allows the administrator to set
 	  a multi-line help message for individual selections.
-	* Fix API call 0x0012 (Shuffle and boot.)
-	* New API call 0x001a "Shuffle and boot to flat protected
-	  mode."
+	* Fix API call 0x0012 (Cleanup, shuffle and boot.)
+	* New API call "Cleanup, shuffle and boot to flat protected mode"
+	* New API call "Cleanup, shuffle and boot to real mode",
+	  similar to API call 0x0012 but allows arbitrary register setting.
 	* Introduce a library interface for loading arbitrary binary
 	  formats with relatively easily understood code.  See
 	  the elf.c32 module for an example on how to use it.
diff --git a/bcopy32.inc b/bcopy32.inc
index 4448c9e7..36af62ee 100644
--- a/bcopy32.inc
+++ b/bcopy32.inc
@@ -487,7 +487,7 @@ trampoline_to_pm:
 		mov ss,ax
 		mov fs,ax
 		mov gs,ax
-		jmp 020h:PMTrampolineBuf ; 20h = 32-bit code segment
+		jmp 020h:TrampolineBuf	; 20h = 32-bit code segment
 
 		align 2
 A20List		dw a20_dunno, a20_none, a20_bios, a20_kbc, a20_fast
@@ -505,4 +505,10 @@ __bcopy_size	equ $-__bcopy_start
 EntryPoint	resd 1			; CS:IP for shuffle_and_boot
 A20Test		resw 1			; Counter for testing status of A20
 A20Tries	resb 1			; Times until giving up on A20
-PMTrampolineBuf	resb 9*9		; Code snippet for invoking PM entry
+
+;
+; This buffer contains synthesized code for shuffle-and-boot.
+; For the PM case, it is 9*5 = 45 bytes long; for the RM case it is
+; 8*6 to set the GPRs, 6*5 to set the segment registers (including a dummy
+; setting of CS), 5 bytes to set CS:IP, for a total of 83 bytes.
+TrampolineBuf	resb 83			; Shuffle and boot trampoline
diff --git a/com32/include/com32.h b/com32/include/com32.h
index 16cd792b..f1df2d61 100644
--- a/com32/include/com32.h
+++ b/com32/include/com32.h
@@ -39,7 +39,7 @@ typedef struct {
   reg32_t edi;			/* Offset  8 */
   reg32_t esi;			/* Offset 12 */
   reg32_t ebp;			/* Offset 16 */
-  reg32_t _unused;		/* Offset 20 */
+  reg32_t _unused_esp;		/* Offset 20 */
   reg32_t ebx;			/* Offset 24 */
   reg32_t edx;			/* Offset 28 */
   reg32_t ecx;			/* Offset 32 */
diff --git a/com32/include/syslinux/bootpm.h b/com32/include/syslinux/bootpm.h
new file mode 100644
index 00000000..6064ea96
--- /dev/null
+++ b/com32/include/syslinux/bootpm.h
@@ -0,0 +1,53 @@
+/* ----------------------------------------------------------------------- *
+ *   
+ *   Copyright 2007 H. Peter Anvin - All Rights Reserved
+ *
+ *   Permission is hereby granted, free of charge, to any person
+ *   obtaining a copy of this software and associated documentation
+ *   files (the "Software"), to deal in the Software without
+ *   restriction, including without limitation the rights to use,
+ *   copy, modify, merge, publish, distribute, sublicense, and/or
+ *   sell copies of the Software, and to permit persons to whom
+ *   the Software is furnished to do so, subject to the following
+ *   conditions:
+ *   
+ *   The above copyright notice and this permission notice shall
+ *   be included in all copies or substantial portions of the Software.
+ *   
+ *   THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
+ *   EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES
+ *   OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
+ *   NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT
+ *   HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY,
+ *   WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
+ *   FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR
+ *   OTHER DEALINGS IN THE SOFTWARE.
+ *
+ * ----------------------------------------------------------------------- */
+
+/*
+ * syslinux/bootpm.h
+ *
+ * Data structures for shuffle and boot to protected mode
+ */
+
+#ifndef _SYSLINUX_BOOTPM_H
+#define _SYSLINUX_BOOTPM_H
+
+#include <stdint.h>
+
+struct syslinux_pm_regs {
+  uint32_t eax;			/* Offset  0 */
+  uint32_t ecx;			/* Offset  4 */
+  uint32_t edx;			/* Offset  8 */
+  uint32_t ebx;			/* Offset 12 */
+  uint32_t esp;			/* Offset 16 */
+  uint32_t ebp;			/* Offset 20 */
+  uint32_t esi;			/* Offset 24 */
+  uint32_t edi;			/* Offset 28 */
+
+  uint32_t eip;			/* Offset 32 */
+};
+
+#endif /* _SYSLINUX_BOOTPM_H */
+
diff --git a/com32/include/syslinux/bootrm.h b/com32/include/syslinux/bootrm.h
new file mode 100644
index 00000000..d7df9fae
--- /dev/null
+++ b/com32/include/syslinux/bootrm.h
@@ -0,0 +1,66 @@
+/* ----------------------------------------------------------------------- *
+ *   
+ *   Copyright 2007 H. Peter Anvin - All Rights Reserved
+ *
+ *   Permission is hereby granted, free of charge, to any person
+ *   obtaining a copy of this software and associated documentation
+ *   files (the "Software"), to deal in the Software without
+ *   restriction, including without limitation the rights to use,
+ *   copy, modify, merge, publish, distribute, sublicense, and/or
+ *   sell copies of the Software, and to permit persons to whom
+ *   the Software is furnished to do so, subject to the following
+ *   conditions:
+ *   
+ *   The above copyright notice and this permission notice shall
+ *   be included in all copies or substantial portions of the Software.
+ *   
+ *   THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
+ *   EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES
+ *   OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
+ *   NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT
+ *   HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY,
+ *   WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
+ *   FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR
+ *   OTHER DEALINGS IN THE SOFTWARE.
+ *
+ * ----------------------------------------------------------------------- */
+
+/*
+ * syslinux/bootrm.h
+ *
+ * Data structures for shuffle and boot to protected mode
+ */
+
+#ifndef _SYSLINUX_BOOTRM_H
+#define _SYSLINUX_BOOTRM_H
+
+#include <stdint.h>
+#include <com32.h>
+
+/* This register set is used by the shuffle and boot interface.  It is
+   a completely different structure from what the __intcall() and
+   __farcall() interfaces use! */
+struct syslinux_rm_regs {
+  uint16_t es;			/* Offset  0 */
+  uint16_t _unused_cs;		/* Offset  2 */
+  uint16_t ds;			/* Offset  4 */
+  uint16_t ss;			/* Offset  6 */
+  uint16_t fs;			/* Offset  8 */
+  uint16_t gs;			/* Offset 10 */
+
+  reg32_t eax;			/* Offset 12 */
+  reg32_t ecx;			/* Offset 16 */
+  reg32_t edx;			/* Offset 20 */
+  reg32_t ebx;			/* Offset 24 */
+  reg32_t esp;			/* Offset 28 */
+  reg32_t ebp;			/* Offset 32 */
+  reg32_t esi;			/* Offset 36 */
+  reg32_t edi;			/* Offset 40 */
+
+  uint16_t ip;			/* Offset 44 */
+  uint16_t cs;			/* Offset 46 */
+};
+
+
+#endif /* _SYSLINUX_BOOTRM_H */
+
diff --git a/com32/include/syslinux/movebits.h b/com32/include/syslinux/movebits.h
index 3a03c622..60fcebd7 100644
--- a/com32/include/syslinux/movebits.h
+++ b/com32/include/syslinux/movebits.h
@@ -43,11 +43,9 @@ struct syslinux_memmap {
 };
 
 
-struct syslinux_pm_regs {
-  uint32_t eax, ecx, edx, ebx;
-  uint32_t esp, ebp, esi, edi;
-  uint32_t eip;
-};
+/* Defined in <syslinux/bootpm.h> and <syslinux/bootrm.h> respectively */
+struct syslinux_pm_regs;
+struct syslinux_rm_regs;
 
 /*
  * moves is computed from "fraglist" and "memmap".  Areas that are
@@ -70,8 +68,7 @@ int syslinux_prepare_shuffle(struct syslinux_movelist *fraglist,
 int syslinux_shuffle_boot_rm(struct syslinux_movelist *fraglist,
 			     struct syslinux_memmap *memmap,
 			     uint16_t bootflags,
-			     uint32_t edx, uint32_t esi, uint16_t ds,
-			     uint16_t cs, uint16_t ip);
+			     struct syslinux_rm_regs *regs);
 int syslinux_shuffle_boot_pm(struct syslinux_movelist *fraglist,
 			     struct syslinux_memmap *memmap,
 			     uint16_t bootflags,
diff --git a/com32/lib/syslinux/shuffle_pm.c b/com32/lib/syslinux/shuffle_pm.c
index f8af66ad..c49ff917 100644
--- a/com32/lib/syslinux/shuffle_pm.c
+++ b/com32/lib/syslinux/shuffle_pm.c
@@ -36,6 +36,7 @@
 #include <com32.h>
 #include <string.h>
 #include <syslinux/movebits.h>
+#include <syslinux/bootpm.h>
 
 int syslinux_shuffle_boot_pm(struct syslinux_movelist *fraglist,
 			     struct syslinux_memmap *memmap,
diff --git a/com32/lib/syslinux/shuffle_rm.c b/com32/lib/syslinux/shuffle_rm.c
index e676e1dd..e87028aa 100644
--- a/com32/lib/syslinux/shuffle_rm.c
+++ b/com32/lib/syslinux/shuffle_rm.c
@@ -28,7 +28,7 @@
 /*
  * shuffle_rm.c
  *
- * Shuffle and boot to real mode code
+ * Shuffle and boot to protected mode code
  */
 
 #include <stdlib.h>
@@ -36,31 +36,33 @@
 #include <com32.h>
 #include <string.h>
 #include <syslinux/movebits.h>
+#include <syslinux/bootrm.h>
 
 int syslinux_shuffle_boot_rm(struct syslinux_movelist *fraglist,
 			     struct syslinux_memmap *memmap,
 			     uint16_t bootflags,
-			     uint32_t edx, uint32_t esi, uint16_t ds,
-			     uint16_t cs, uint16_t ip)
+			     struct syslinux_rm_regs *regs)
 {
   int nd;
   com32sys_t ireg;
+  char *regbuf;
 
   nd = syslinux_prepare_shuffle(fraglist, memmap);
   if (nd < 0)
     return -1;
   
+  regbuf = (char *)__com32.cs_bounce + (12*nd);
+  memcpy(regbuf, regs, sizeof(*regs));
+
   memset(&ireg, 0, sizeof ireg);
   
-  ireg.eax.w[0] = 0x0012;
+  ireg.eax.w[0] = 0x001b;
   ireg.edx.w[0] = bootflags;
   ireg.es       = SEG(__com32.cs_bounce);
   ireg.edi.l    = OFFS(__com32.cs_bounce);
   ireg.ecx.l    = nd;
-  ireg.ebx.l    = edx;
-  ireg.esi.l    = esi;
-  ireg.ds       = ds;
-  ireg.ebp.l    = (cs << 16) + ip;
+  ireg.ds       = SEG(regbuf);
+  ireg.esi.l    = OFFS(regbuf);
   __intcall(0x22, &ireg, NULL);
 
   return -1;			/* Too many descriptors? */
diff --git a/com32/modules/elf.c b/com32/modules/elf.c
index a049bc83..bdbf6e5d 100644
--- a/com32/modules/elf.c
+++ b/com32/modules/elf.c
@@ -44,6 +44,7 @@
 
 #include <syslinux/loadfile.h>
 #include <syslinux/movebits.h>
+#include <syslinux/bootpm.h>
 
 /* If we don't have this much memory for the stack, signal failure */
 #define MIN_STACK	512
diff --git a/comboot.doc b/comboot.doc
index bc6433c0..706fddee 100644
--- a/comboot.doc
+++ b/comboot.doc
@@ -100,7 +100,7 @@ int _start(unsigned int __nargs,
 The intcall helper function can be used to issue BIOS or SYSLINUX API
 calls, and takes the interrupt number as first argument.  The second
 argument is a pointer to the input register definition, an instance of
-the following structure (also available in com32.h):
+the following structure (available in <com32.h>):
 
 typedef union {
   uint32_t l;
@@ -117,7 +117,7 @@ typedef struct {
   reg32_t edi;			/* Offset  8 */
   reg32_t esi;			/* Offset 12 */
   reg32_t ebp;			/* Offset 16 */
-  reg32_t _unused;		/* Offset 20 */
+  reg32_t _unused_esp;		/* Offset 20 */
   reg32_t ebx;			/* Offset 24 */
   reg32_t edx;			/* Offset 28 */
   reg32_t ecx;			/* Offset 32 */
@@ -778,12 +778,67 @@ AX=001Ah [3.40] Cleanup, shuffle and boot to flat protected mode
 	for the meaning of ES:DI and CX.
 
 	DS:SI points to the initial register file, which is a structure
-	of 9 dwords in the following order:
+	of 9 dwords (available in <syslinux/bootpm.h>):
 
-	EAX, ECX, EDX, EBX, ESP, EBP, ESI, EDI, EIP
+	struct syslinux_pm_regs {
+	  uint32_t eax;			/* Offset  0 */
+	  uint32_t ecx;			/* Offset  4 */
+	  uint32_t edx;			/* Offset  8 */
+	  uint32_t ebx;			/* Offset 12 */
+	  uint32_t esp;			/* Offset 16 */
+	  uint32_t ebp;			/* Offset 20 */
+	  uint32_t esi;			/* Offset 24 */
+	  uint32_t edi;			/* Offset 28 */
+
+	  uint32_t eip;			/* Offset 32 */
+	};
 
 	Protected mode is entered with all data segments set up as a
 	flat 32-bit read/write segment and the code segment a flat 32-bit
-	read/execute segment.  Interrupts are off, and GDT, LDT and
-	IDT are undefined; it is up to the invoked code to set new
-	descriptor tables to its liking.
+	read/execute segment.  Interrupts and paging is off, CPL=0, DF=0;
+	however, GDT, LDT and IDT are undefined, so it is up to the
+	invoked code to set new	descriptor tables to its liking.
+
+
+AX=001Bh [3.40] Cleanup, shuffle and boot to real mode
+	Input:	AX	001Ah
+		DX	derivative-specific flags (see function 000Ch)
+		ES:DI	shuffle descriptor list (must be in low memory)
+		CX	number of shuffle descriptors
+		DS:SI	pointer to register values (must be in low memory)
+	Output:	Does not return
+		(if CX is too large the routine returns with CF=1)
+
+	This routine performs final cleanup, then performs a sequence
+	of copies, and jumps to a specified entry point.
+	This is similar to function 0012h but allow more control over
+	the initial register state; see that function for the meaning of
+	ES:DI and CX.
+
+	DS:SI points to the initial register file, which is a structure
+	in the following format (available in <syslinux/bootrm.h>;
+	note that this is a completely different structure from the
+	com32sys_t structure described at the top of this document!):
+
+	struct syslinux_rm_regs {
+	  uint16_t es;			/* Offset  0 */
+	  uint16_t _unused_cs;		/* Offset  2 */
+	  uint16_t ds;			/* Offset  4 */
+	  uint16_t ss;			/* Offset  6 */
+	  uint16_t fs;			/* Offset  8 */
+	  uint16_t gs;			/* Offset 10 */
+
+	  reg32_t eax;			/* Offset 12 */
+	  reg32_t ecx;			/* Offset 16 */
+	  reg32_t edx;			/* Offset 20 */
+	  reg32_t ebx;			/* Offset 24 */
+	  reg32_t esp;			/* Offset 28 */
+	  reg32_t ebp;			/* Offset 32 */
+	  reg32_t esi;			/* Offset 36 */
+	  reg32_t edi;			/* Offset 40 */
+
+	  uint16_t ip;			/* Offset 44 */
+	  uint16_t cs;			/* Offset 46 */
+	};
+
+	Interrupts are off and DF=0 on entry.
diff --git a/comboot.inc b/comboot.inc
index 70d7d7b3..576e4d0f 100644
--- a/comboot.inc
+++ b/comboot.inc
@@ -818,9 +818,9 @@ comapi_shufflepm:
 
 		mov fs,P_DS
 		mov si,P_SI
-		mov edi,PMTrampolineBuf
+		mov edi,TrampolineBuf
 		mov al,0B8h			; MOV EAX opcode
-		mov cx,9
+		mov cl,9
 .maketramp:
 		stosb				; MOV opcode
 		inc ax				; Next register opcode
@@ -836,6 +836,64 @@ comapi_shufflepm:
 		stc
 		ret
 
+;
+; INT 22h AX=001Bh	Cleanup, shuffle and boot with register setting
+;
+comapi_shufflerm:
+		cmp P_CX,(2*trackbufsize)/12
+		ja .error
+
+		call comapi_cleanup
+
+		mov cx, P_CX
+		push cx				; On stack: descriptor count
+
+		lea cx,[ecx+ecx*2]		; CX *= 3
+
+		mov fs,P_ES
+		mov si,P_DI
+		mov di,trackbuf
+		push di				; On stack: descriptor list address
+		fs rep movsd			; Copy the list
+
+		mov fs,P_DS
+		mov si,P_SI
+		mov di,TrampolineBuf
+
+		; Generate segment-loading instructions
+		mov bx,0C08Eh			; MOV ES,AX
+		mov cl,6			; 6 segment registers (incl CS)
+.segtramp:
+		mov al,0B8h
+		stosb				; MOV AX,imm16 opcode
+		fs movsw			; imm16
+		mov ax,bx
+		stosw				; MOV xS,AX
+		loop .segtramp
+
+		; Clobber the MOV CS,AX instruction.  This changes it
+		; into [89 C8], a harmless "MOV AX,CX".
+		mov byte [di-22], 89h
+
+		; Generate GPR-loading instructions
+		mov ax,0B866h			; MOV EAX,imm32
+		mov cl,8			; 8 GPRs
+.gprtramp:
+		stosw				; MOV ExX,imm32 opcode
+		fs movsd			; imm32
+		inc ah
+		loop .gprtramp
+
+		mov al,0EAh			; JMP FAR imm16:imm16 opcode
+		stosb
+		fs movsd			; CS:IP
+
+		mov dword [EntryPoint],TrampolineBuf
+		jmp replace_bootstrap
+.error:
+		stc
+		ret
+
 		section .data
 
 %macro 		int21 2
@@ -885,6 +943,7 @@ int22_table:
 		dw comapi_userfont	; 0018 query custom font
 		dw comapi_readdisk	; 0019 read disk
 		dw comapi_shufflepm	; 001A cleanup, shuffle and boot to pm
+		dw comapi_shufflerm	; 001B cleanup, shuffle and boot to rm
 int22_count	equ ($-int22_table)/2
 
 APIKeyWait	db 0
diff --git a/sample/filetest.c b/sample/filetest.c
index 18b08361..b4ca2d80 100644
--- a/sample/filetest.c
+++ b/sample/filetest.c
@@ -26,7 +26,7 @@ static void printregs(const com32sys_t *r)
 	 "ebp = %08x  esi = %08x  edi = %08x  esp = %08x\n",
 	 r->eflags.l, r->ds, r->es, r->fs, r->gs,
 	 r->eax.l, r->ebx.l, r->ecx.l, r->edx.l,
-	 r->ebp.l, r->esi.l, r->edi.l, r->_unused.l);
+	 r->ebp.l, r->esi.l, r->edi.l, r->_unused_esp.l);
 }
 
 int __start(void)