/*
 * Common Option ROM Functions
 *
 * 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, see <http://www.gnu.org/licenses/>.
 *
 * Copyright Novell Inc, 2009
 *   Authors: Alexander Graf <agraf@suse.de>
 */


#define FW_CFG_KERNEL_ADDR      0x07
#define FW_CFG_KERNEL_SIZE      0x08
#define FW_CFG_KERNEL_CMDLINE   0x09
#define FW_CFG_INITRD_ADDR      0x0a
#define FW_CFG_INITRD_SIZE      0x0b
#define FW_CFG_KERNEL_ENTRY     0x10
#define FW_CFG_KERNEL_DATA      0x11
#define FW_CFG_INITRD_DATA      0x12
#define FW_CFG_CMDLINE_ADDR     0x13
#define FW_CFG_CMDLINE_SIZE     0x14
#define FW_CFG_CMDLINE_DATA     0x15
#define FW_CFG_SETUP_ADDR       0x16
#define FW_CFG_SETUP_SIZE       0x17
#define FW_CFG_SETUP_DATA       0x18

#define BIOS_CFG_IOPORT_CFG	0x510
#define BIOS_CFG_IOPORT_DATA	0x511

#define FW_CFG_DMA_CTL_ERROR   0x01
#define FW_CFG_DMA_CTL_READ    0x02
#define FW_CFG_DMA_CTL_SKIP    0x04
#define FW_CFG_DMA_CTL_SELECT  0x08
#define FW_CFG_DMA_CTL_WRITE   0x10

#define FW_CFG_DMA_SIGNATURE 0x51454d5520434647ULL /* "QEMU CFG" */

#define BIOS_CFG_DMA_ADDR_HIGH  0x514
#define BIOS_CFG_DMA_ADDR_LOW   0x518

/* Break the translation block flow so -d cpu shows us values */
#define DEBUG_HERE \
	jmp		1f;				\
	1:
	
/*
 * Read a variable from the fw_cfg device.
 * Clobbers:	%edx
 * Out:		%eax
 */
.macro read_fw VAR
	mov		$\VAR, %ax
	mov		$BIOS_CFG_IOPORT_CFG, %dx
	outw		%ax, (%dx)
	mov		$BIOS_CFG_IOPORT_DATA, %dx
	inb		(%dx), %al
	shl		$8, %eax
	inb		(%dx), %al
	shl		$8, %eax
	inb		(%dx), %al
	shl		$8, %eax
	inb		(%dx), %al
	bswap		%eax
.endm


/*
 * Read data from the fw_cfg device using DMA.
 * Clobbers:	%edx, %eax, ADDR, SIZE, memory[%esp-16] to memory[%esp]
 */
.macro read_fw_dma VAR, SIZE, ADDR
        /* Address */
	bswapl		\ADDR
	pushl		\ADDR

	/* We only support 32 bit target addresses */
	xorl		%eax, %eax
	pushl		%eax
	mov		$BIOS_CFG_DMA_ADDR_HIGH, %dx
	outl		%eax, (%dx)

	/* Size */
	bswapl		\SIZE
	pushl		\SIZE

        /* Control */
	movl		$(\VAR << 16) | (FW_CFG_DMA_CTL_READ | FW_CFG_DMA_CTL_SELECT), %eax
	bswapl		%eax
	pushl		%eax

	movl		%esp, %eax /* Address of the struct we generated */
	bswapl		%eax
	mov		$BIOS_CFG_DMA_ADDR_LOW, %dx
	outl		%eax, (%dx) /* Initiate DMA */

1:  mov		(%esp), %eax /* Wait for completion */
	bswapl		%eax
	testl		$~FW_CFG_DMA_CTL_ERROR, %eax
	jnz		1b
       addl            $16, %esp
.endm


/*
 * Read a blob from the fw_cfg device using DMA
 * Requires _ADDR, _SIZE and _DATA values for the parameter.
 *
 * Clobbers:	%eax, %edx, %es, %ecx, %edi and adresses %esp-20 to %esp
 */
#ifdef USE_FW_CFG_DMA
#define read_fw_blob_dma(var) \
	read_fw		var ## _SIZE; \
	mov		%eax, %ecx; \
	read_fw		var ## _ADDR; \
	mov		%eax, %edi ;\
	read_fw_dma	var ## _DATA, %ecx, %edi
#else
#define read_fw_blob_dma(var) read_fw_blob(var)
#endif

#define read_fw_blob_pre(var)				\
	read_fw		var ## _SIZE;			\
	mov		%eax, %ecx;			\
	mov		$var ## _DATA, %ax;		\
	mov		$BIOS_CFG_IOPORT_CFG, %edx;	\
	outw		%ax, (%dx);			\
	mov		$BIOS_CFG_IOPORT_DATA, %dx;	\
	cld

/*
 * Read a blob from the fw_cfg device.
 * Requires _ADDR, _SIZE and _DATA values for the parameter.
 *
 * Clobbers:	%eax, %edx, %es, %ecx, %edi
 */
#define read_fw_blob(var)				\
	read_fw		var ## _ADDR;			\
	mov		%eax, %edi;			\
	read_fw_blob_pre(var);				\
	/* old as(1) doesn't like this insn so emit the bytes instead: \
	rep insb	(%dx), %es:(%edi);		\
	*/						\
	.dc.b		0xf3,0x6c

/*
 * Read a blob from the fw_cfg device in forced addr32 mode.
 * Requires _ADDR, _SIZE and _DATA values for the parameter.
 *
 * Clobbers:	%eax, %edx, %es, %ecx, %edi
 */
#define read_fw_blob_addr32(var)			\
	read_fw		var ## _ADDR;			\
	mov		%eax, %edi;			\
	read_fw_blob_pre(var);				\
	/* old as(1) doesn't like this insn so emit the bytes instead: \
	addr32 rep insb	(%dx), %es:(%edi);		\
	*/						\
	.dc.b		0x67,0xf3,0x6c

/*
 * Read a blob from the fw_cfg device in forced addr32 mode, address is in %edi.
 * Requires _SIZE and _DATA values for the parameter.
 *
 * Clobbers:	%eax, %edx, %edi, %es, %ecx
 */
#define read_fw_blob_addr32_edi(var)			\
	read_fw_blob_pre(var);				\
	/* old as(1) doesn't like this insn so emit the bytes instead: \
	addr32 rep insb	(%dx), %es:(%edi);		\
	*/						\
	.dc.b		0x67,0xf3,0x6c

#define OPTION_ROM_START					\
    .code16;						\
    .text;						\
	.global 	_start;				\
    _start:;						\
	.short		0xaa55;				\
	.byte		(_end - _start) / 512;

#define BOOT_ROM_START					\
	OPTION_ROM_START				\
	lret;						\
	.org 		0x18;				\
	.short		0;				\
	.short		_pnph;				\
    _pnph:						\
	.ascii		"$PnP";				\
	.byte		0x01;				\
	.byte		( _pnph_len / 16 );		\
	.short		0x0000;				\
	.byte		0x00;				\
	.byte		0x00;				\
	.long		0x00000000;			\
	.short		_manufacturer;			\
	.short		_product;			\
	.long		0x00000000;			\
	.short		0x0000;				\
	.short		0x0000;				\
	.short		_bev;				\
	.short		0x0000;				\
	.short		0x0000;				\
	.equ		_pnph_len, . - _pnph;		\
    _bev:;						\
	/* DS = CS */					\
	movw		%cs, %ax;			\
	movw		%ax, %ds;

#define OPTION_ROM_END					\
	.byte		0;				\
	.align		512, 0;				\
    _end:

#define BOOT_ROM_END					\
    _manufacturer:;					\
	.asciz "QEMU";					\
    _product:;						\
	.asciz BOOT_ROM_PRODUCT;			\
	OPTION_ROM_END