src/parisc/head.S - seabios-hppa - Git at Google

 /*
  * Startup glue code for parisc firmware
  *
  *   (C) 2017-2024 Helge Deller <deller@gmx.de>
  */

 #include "parisc/hppa.h"
 #include "parisc/hppa_hardware.h"
 #include "parisc/pdc.h"
 #include "autoconf.h"
 #include "autoversion.h"

 	/* load 32-bit 'value' into 'reg' with
 	   sign-extension when running in wide mode. */
 	.macro	load32_sign_extend value, reg
 	ldil	L%\value, \reg
 	ldo	R%\value(\reg), \reg
 	.endm

 	/* load 32-bit 'value' into 'reg' compensating for the ldil
 	 * sign-extension when running in wide mode. */
 	.macro	load32 value, reg
 	ldil	L%\value, \reg
 	ldo	R%\value(\reg), \reg
 #ifdef CONFIG_64BIT
 	depdi   0, 31, 32, \reg
 #endif
 	.endm

 	/* set upper 32-bits of firmware address */
 	.macro	load_fw_upper32 reg
 #ifdef CONFIG_64BIT
 	depdi   FIRMWARE_HIGH, 31, 32, \reg
 #endif
 	.endm

 	.macro	load32_firmware value, reg
 	ldil	L%\value, \reg
 	ldo	R%\value(\reg), \reg
 #ifdef CONFIG_64BIT
 	depdi   FIRMWARE_HIGH, 31, 32, \reg
 #endif
 	.endm

 ;! set the W bit
 #define set_PSW_W	.level 2.0 !	ssm PSW_W_SM, %r0 !	.level LEVEL

 ;! nuke the W bit
 #define clear_PSW_W	.level 2.0 !	rsm PSW_W_SM, %r0 !	.level LEVEL

 #define ENTRY(name) \
 	.export name !\
 	.align 4 !\
 name:

 #define END(name) \
 	.size name, .-name

 #define ENDPROC(name) \
 	.type name, @function !\
 	END(name)

 #define BOOTADDR(x)	(x)

 	.macro loadgp
 #ifdef CONFIG_64BIT
 	ldil		L%__gp, %r27
 	ldo		R%__gp(%r27), %r27
 	load_fw_upper32	%r27
 #else
 	ldil		L%$global$, %r27
 	ldo		R%$global$(%r27), %r27
 #endif
 	.endm

 #ifdef CONFIG_64BIT
 #define LEVEL	2.0w
 #define LDREG	ldd
 #define STREG	std
 #define LDREGX  ldd,s
 #define LDREGM	ldd,mb
 #define STREGM	std,ma
 #define SHRREG	shrd
 #define SHLREG	shld
 #define ANDCM   andcm,*
 #define	COND(x)	* ## x
 #define FRAME_SIZE	128
 #define FRAME_SIZE32	64
 #define CALLEE_REG_FRAME_SIZE	144
 #define ASM_ULONG_INSN	.dword
 #define WORD_LEN 8
 #define INT_LEN 4
 #else	/* CONFIG_64BIT */
 #define LEVEL	1.1
 #define LDREG	ldw
 #define STREG	stw
 #define LDREGX  ldwx,s
 #define LDREGM	ldwm
 #define STREGM	stwm
 #define SHRREG	shr
 #define SHLREG	shlw
 #define ANDCM   andcm
 #define COND(x)	x
 #define FRAME_SIZE	64
 #define CALLEE_REG_FRAME_SIZE	128
 #define ASM_ULONG_INSN	.word
 #define WORD_LEN 4
 #define INT_LEN 4
 #endif

 /* various control register and irq bits */
 #define PSW_I		1
 #define PSW_Q		8
 #define CR_EIRR		23
 #define CR_IVA		14
 #define CR_EIEM		15
 #define PSW_W_SM	0x200
 #define PSW_W_BIT       36

 	.import	$global$
 	.section ".head.text","ax"
 	 .level LEVEL

 	/* On HPMC, the CPUs will start here at 0xf0000000 */
 hpmc_entry:
         b,n toc_asm_entry       /* TOC and HPMC */

 reset_entry:
 	/* at reset, the CPU begins fetching instructions from address 0xf0000004. */
 	b,n startup

 marker:
 	/* file identification, useful for strings command on binary file to see version. */
 	.stringz "PA-RISC/HPPA PDC Firmware " SEABIOS_HPPA_VERSION_STR " (SeaBIOS fork)"
 	.stringz "https://github.com/hdeller/seabios-hppa"
 	.stringz BUILD_VERSION

 /*******************************************************
 	Firmware startup code
  *******************************************************/

         .align 0x80
 ENTRY(startup)
 	rsm	PSW_I, %r0	/* disable local irqs */
 	ssm	PSW_Q, %r0	/* enable PSW_Q flag */

 #ifdef CONFIG_64BIT
 	/* check if we really run on 64-bit CPU */
 	ldo	-1(%r0), %r1
 	mtctl	%r1,%cr11
 	mfctl,w %cr11, %r1
 	ldo	-31(%r1),%r1
 	cmpib,<>,n 0,%r1,1f
 	.word 0xfffdead0	/* immediately halt the emulator */
 1:
 	/* we now know we run on a 64-bit CPU. */
 	/* next step: turn on the PSW.W flag (enable 64-bit mode) */
 	load32		2f,%r11
 	load_fw_upper32 %r11

 	mtctl           %r0,%cr17       /* Clear IIASQ tail */
 	mtctl           %r0,%cr17       /* Clear IIASQ head */

 	/* Load RFI target into PC queue */
 	mtctl           %r11,%cr18      /* IIAOQ head */
 	ldo             4(%r11),%r11
 	mtctl           %r11,%cr18      /* IIAOQ tail */

 	load32          (0x08000000 | PSW_Q),%r10 /* PSW.W=1 */
 	mtctl           %r10,%ipsw

 	/* Jump through hyperspace to enable PSW.W */
 	rfi
 	nop
 2:
 #else
 	/* clear any PSW.W on 32-bit firmware */
 	clear_PSW_W
 #endif

 	/* Make sure space registers are set to zero */
 	mtsp    %r0,%sr0
 	mtsp    %r0,%sr1
 	mtsp    %r0,%sr2
 	mtsp    %r0,%sr3
 	mtsp    %r0,%sr4
 	mtsp    %r0,%sr5
 	mtsp    %r0,%sr6
 	mtsp    %r0,%sr7

 	/* If CPU HPA is already set in CPU_HPA_CR_REG then the
 	 * CPU is already initialized and the machine was only reset */
 	mfctl   CPU_HPA_CR_REG, %r1
 	comib,= 0,%r1,$startup_fresh_booted
 	nop

 $startup_just_rebooted:
 	/* Get current CPU HPA. It was stored there at initial bootup. */
 	mfctl   CPU_HPA_CR_REG, %r5

 	/* branch if this is the monarch cpu */
 	load32_sign_extend CPU_HPA, %r1
 	comb,=,n %r5,%r1,$is_monarch_cpu_reboot

 	b,n	enter_smp_idle_loop

 $startup_fresh_booted:
 	/* Here the machine was booted from scratch: */

 	/* Save CPU HPA in cr7, hopefully HP-UX will not use that register. */
 #ifdef CONFIG_64BIT
 	extrw,s,>= %r5,31,32,%r5	/* sign extend CPU HPA */
 #endif
 	mtctl   %r5, CPU_HPA_CR_REG /* store CPU HPA */

 	/* branch if this is the monarch cpu */
 	load32_sign_extend CPU_HPA,%r1
 	comb,= %r5,%r1,$is_monarch_cpu
 	nop

 ENTRY(enter_smp_idle_loop)
 	/* IDLE LOOP for SMP CPUs - wait for rendenzvous. */
 	mfctl   CPU_HPA_CR_REG, %r25 /* get CPU HPA from cr7 */

 	rsm	PSW_I, %r0	/* disable local irqs */
 	mtctl	%r0, CR_EIEM	/* disable all external irqs */

 	/* EIRR : clear all pending external intr */
 	load32	-1,%r1
 	mtctl	%r1, CR_EIRR
 	mfctl	CR_EIRR, %r0
 	mtctl	%r0, CR_EIRR

 	/* Load IVT for SMT tiny loop exit */
 	load32_firmware	BOOTADDR(smp_ivt),%r1
 	mtctl	%r1, CR_IVA

 	/* enable CPU local interrupts */
 	load32	1<<31, %r1	/* allow IRQ0 (Timer) */
 	mtctl	%r1, CR_EIEM
 	ssm	PSW_I, %r0	/* enable local irqs */

 	/* endless idle loop for secondary CPUs. Exits to $smp_exit_loop by IRQ only */
 $smp_idle_loop:
 	b $smp_idle_loop
 	or %r10,%r10,%r10	/* qemu sleep instruction */

 $smp_exit_loop:
 	rsm	PSW_I, %r0	/* disable local irqs */
 	mtctl	%r0, CR_EIEM

 	/* Load IVT to detect and report crashes */
 	load32_firmware	BOOTADDR(firmware_default_ivt),%r1
 	mtctl	%r1, CR_IVA

 	/* provide PDCE_PROC entry in arg0 (required on 64-bit) */
 	load32	MEM_PDC_ENTRY, %arg0

 	/* jump to rendevouz */
 	ldw	0x10(%r0),%r3	/* MEM_RENDEZ */
 #ifdef CONFIG_64BIT
 	addb,*>,n %r0,%r0,1f	/* branch if narrow addressing */
 	ldw	0x28(%r0),%r1	/* MEM_RENDEZ_HI */
 	depd    %r1, 31, 32, %r3
 1:
 #endif
 	cmpb,=,n  %r0,%r3,enter_smp_idle_loop
 	nop			/* failed backward branch is nullified */
 	load32_firmware	startup, %rp
 	bv,n	0(%r3)

 $is_monarch_cpu:
 	/* Save boot_args in PAGE0->pad608[]. Only monarch CPU does this once. */
         load32          BOOTADDR(0x608),%r1
         STREGM          %r26,WORD_LEN(%r1)
         STREGM          %r25,WORD_LEN(%r1)
         STREGM          %r24,WORD_LEN(%r1)
         STREGM          %r23,WORD_LEN(%r1)
         STREGM          %r22,WORD_LEN(%r1)
         STREGM          %r21,WORD_LEN(%r1)
         STREGM          %r20,WORD_LEN(%r1)
         STREGM          %r19,WORD_LEN(%r1)

 $is_monarch_cpu_reboot:
 	/* Initialize stack pointer */
 	load32_firmware BOOTADDR(parisc_stack),%r1
 	ldo	FRAME_SIZE(%r1),%sp

 	/* Initialize the global data pointer */
 	loadgp

 	/* Clear BSS on monarch CPU */
 	.import _bss,data
 	.import _ebss,data

 	load32_firmware	BOOTADDR(_bss),%r3
 	load32_firmware	BOOTADDR(_ebss),%r4
 $bss_loop:
 	cmpb,<<,n %r3,%r4,$bss_loop
 	STREGM	%r0,WORD_LEN(%r3)

 	/* Load IVT to detect and report crashes */
 	load32_firmware	BOOTADDR(firmware_default_ivt),%r1
 	mtctl	%r1, CR_IVA

 	load32_firmware	BOOTADDR(start_parisc_firmware),%r3
 	bv	0(%r3)
 	copy	%r0,%r2
 END(startup)

 /*******************************************************/

 ENTRY(start_kernel)
 #ifdef CONFIG_64BIT
 	bv	0(%r22)
 	clear_PSW_W	/* clear PSW before we start the kernel! */
 #else
 	ldw	-0x34(%sp),%r1
 	bv,n	0(%r1)
 #endif
 END(start_kernel)

 /*******************************************************
   TOC handler
   Write all GRs, CRs, SRs and the iaoq_back and iasq_back registers (in
   r24/r25) into PIM area (when it's not filled yet). This is done by trashing the
   shadow registers.
   In a second step call the arificial getshadowregs asm instruction to restore
   the shadow registers to their real values and store them in PIM as well.  Then
   call the C-code.
  *******************************************************/

 /* uses the shadow registers: 1,8,9,16,17,24,25 */
 #define PIM_PTR         %r1
 #define TEMP            %r8
 #define TEMP2           %r9
 #define PIM_SAVE        %r16
 #define IASQ_BACK       %r24    /* provided by qemu */
 #define IAOQ_BACK       %r25    /* provided by qemu */

         .import pim_toc_data, data
 ENTRY(toc_asm_entry)
         /* serialize CPUs on entry */
         load32_firmware BOOTADDR(toc_lock),TEMP
 0:      ldcw,co 0(TEMP),TEMP2
         cmpib,= 0,TEMP2,0b
         nop

         mfctl   CPU_HPA_CR_REG, TEMP2   /* get CPU HPA from cr7 */
         extru   TEMP2,31-12,4, TEMP     /* extract cpu id */

         load32_firmware BOOTADDR(pim_toc_data), PIM_PTR

 1:      comib,= 0,TEMP,2f
         ldo     -1(TEMP),TEMP
         ldo     (PIM_STORAGE_SIZE)(PIM_PTR), PIM_PTR /* find PIM entry */
         b 1b

 2:      copy    PIM_PTR, PIM_SAVE
         mtsp    %r0,%sr0

         /* save registers into PIM only if cpu_state field is empty */
         ldw     ((32+32+8+2)*WORD_LEN + 1*INT_LEN)(PIM_SAVE), TEMP
         comib,<>,n 0, TEMP, 5f

         /* save all general registers */
         .set loop,0
         .rept 32
         copy    loop,TEMP
         STREGM  TEMP, WORD_LEN(PIM_PTR)
         .set loop,loop+1
         .endr

         /* save all control registers */
         .set loop,0
         .rept 32
         mfctl   loop,TEMP
         STREGM  TEMP, WORD_LEN(PIM_PTR)
         .set loop,loop+1
         .endr

         /* save all space registers */
         .set loop,0
         .rept 8
         mfsp    loop,TEMP
         STREGM  TEMP, WORD_LEN(PIM_PTR)
         .set loop,loop+1
         .endr

         /* save IASQ_back and IAOQ_back as provided by qemu */
         STREG   IASQ_BACK, ((32+32+8+0)*WORD_LEN)(PIM_SAVE)
         STREG   IAOQ_BACK, ((32+32+8+1)*WORD_LEN)(PIM_SAVE)

         /* restore shadow registers, can not use PIM_SAVE reg for this */
         copy    PIM_SAVE, %r26
         .word 0xfffdead2 /* qemu artificial getshadowregs asm instruction */
         STREG   %r1, (1*WORD_LEN)(%r26)
         STREG   %r8, (8*WORD_LEN)(%r26)
         STREG   %r9, (9*WORD_LEN)(%r26)
         STREG   %r16, (16*WORD_LEN)(%r26)
         STREG   %r17, (17*WORD_LEN)(%r26)
         STREG   %r24, (24*WORD_LEN)(%r26)
         STREG   %r25, (25*WORD_LEN)(%r26)

 #ifdef CONFIG_64BIT
         /* cr11 (sar) is a funny one.  5 bits on PA1.1 and 6 bit on PA2.0
          * For PA2.0 mtsar or mtctl always write 6 bits, but mfctl only
          * reads 5 bits.  Use mfctl,w to read all six bits.  Otherwise
          * we lose the 6th bit on a save/restore. */
         mfctl,w %cr11, TEMP
         STREG   TEMP, ((32+11)*WORD_LEN)(%r26)
 #endif

 5:      /* call the "C" toc_handler in SeaBIOS */
         loadgp
         load32_firmware BOOTADDR(parisc_stack), %sp
         b,l     toc_handler, %r2
         ldo     FRAME_SIZE(%sp),%sp

         /* call OS handler, in case it returns reset the system */
         load32_firmware BOOTADDR(reset), %rp
         bv,n    0(%ret0)
 END(toc_asm_entry)


 /*******************************************************
 	SMP Interrupt vector table (IVT)
  *******************************************************/

 	.macro  DEF_IVA_ENTRY
 	.align 32
 	load32_firmware BOOTADDR($smp_exit_loop),%r1
 	bv	0(%r1)
 	nop
 	.endm

 	.align 32	/* should be 4k aligned but qemu does not check */
 ENTRY(smp_ivt)
 	.rept 32
 	DEF_IVA_ENTRY
 	.endr
 END(smp_ivt)

 /*******************************************************
 	Fault detection & reporting Interrupt vector table (IVT)
  *******************************************************/

 /* fault happened at bootup. Return to instruction after fault. */
 ENTRY(fault_return_to_caller)
 	mfctl	%cr18,TEMP
 	ldo	4(TEMP),TEMP
 	mtctl	TEMP,%cr18	/* IIAOQ head */
 	ldo	4(TEMP),TEMP
 	mtctl	TEMP,%cr18	/* IIAOQ tail */
 	rfi
 	nop
 END(fault_return_to_caller)

 /* call firmware_fault_handler in parisc.c and halt. */
 ENTRY(fault_call_firmware)
 	load32_firmware firmware_fault_handler,TEMP
 	loadgp
 	bv,n	0(TEMP)
 END(fault_call_firmware)

 	.align 32
 ENTRY(firmware_default_ivt)	/* to detect crashes */
 	.set loop,0
 	.import firmware_fault_handler,code
 	.rept 32
 	/* Make sure to use shadow registers only! */
 	/* While booting up we check if various devices are available.
 	   Allow such checks and do not raise an HPMC. */
 	ldi	loop,TEMP	/* trap# into TEMP */
 	cmpib,= 1,TEMP,fault_return_to_caller
 	nop
 	b	fault_call_firmware
 	ldi	loop,%arg0	/* trap# into arg0 */
 	.set loop,loop+1
 	.align 32
 	.endr
 END(smp_ivt)


 /*******************************************************
 	PDC and IODC entry
  *******************************************************/

 /* pdc_entry_table will be copied into low memory. */
 ENTRY(pdc_entry_table)
 #ifdef CONFIG_64BIT
 	/* see section "Testing the Current State of the PSW W-Bit",
 	   page I-2 in parisc2 spec */
 	addb,*>,n %r0,%r0,pdc_called_narrow /* branch if narrow addressing */

 pdc_called_wide:
 	/* we know that PDC was called with PSW.W=1 */
 	load32_firmware pdc_entry_64_64,%r1
 	bv,n %r0(%r1)

 pdc_called_narrow:
 	/* we know that PDC was called with PSW.W=0 */
 	load32		MEM_PDC_ENTRY + pdc_entry_64_32 - pdc_entry_table,%r1
 	bv              0(%r1)
 	set_PSW_W	/* enable PSW.W */
 #else
 ENTRY(pdc_entry_32)	/* 32-bit PDC */
 	stw %rp,-20(%sp)
 	stw %dp,-32(%sp)
 	stw %arg0,-36(%sp)
 	stw %arg1,-40(%sp)
 	stw %arg2,-44(%sp)
 	stw %arg3,-48(%sp)
 	ldo -FRAME_SIZE(%sp),%arg0
 	ldi 1,%arg1		/* called with wide-bit cleared (narrow mode) */

 	loadgp
 	load32		MEM_PDC_ENTRY + 1f - pdc_entry_table,%rp
 	load32 parisc_pdc_entry, %r1
 	clear_PSW_W
 	bv              0(%r1)
 	ldo FRAME_SIZE(%sp),%sp
 1:
 	ldo -FRAME_SIZE(%sp),%sp
 	ldw -20(%sp),%rp
 	ldw -32(%sp),%dp
 	bv,n %r0(%rp)
 END(pdc_entry_32)
 #endif
 END(pdc_entry_table)

 #ifdef CONFIG_64BIT
 ENTRY(pdc_entry_64_32)	/* 32-bit call on 64-bit PDC */
 	/* clear upper bits */
 	depdi   0, 31, 32, %sp
 	depdi   0, 31, 32, %rp
 	depdi   0, 31, 32, %dp
 	depdi   0, 31, 32, %arg0
 	depdi   0, 31, 32, %arg1
 	depdi   0, 31, 32, %arg2
 	depdi   0, 31, 32, %arg3

 	copy %sp,%r1	/* copy original stack pointer */
 	ldo 2*FRAME_SIZE(%sp),%sp /* build new 64-bit stack */

 	std %rp,-0x10(%sp)
 	std %dp,-0x18(%sp)
 	std %arg0,-0x20(%sp)
 	std %arg1,-0x28(%sp)
 	std %arg2,-0x30(%sp)
 	std %arg3,-0x38(%sp)

 	ldw -FRAME_SIZE32 + 12(%r1),%arg0	/* ARG4 */
 	depdi   0, 31, 32, %arg0
 	std %arg0, -0x40(%sp)

 	ldw -FRAME_SIZE32 + 8(%r1),%arg0	/* ARG5 */
 	depdi   0, 31, 32, %arg0
 	std %arg0, -0x48(%sp)

 	ldw -FRAME_SIZE32 + 4(%r1),%arg0	/* ARG6 */
 	depdi   0, 31, 32, %arg0
 	std %arg0, -0x50(%sp)

 	ldw -FRAME_SIZE32 + 0(%r1),%arg0	/* ARG7 */
 	depdi   0, 31, 32, %arg0
 	std %arg0, -0x58(%sp)

 	ldo -0x58(%sp),%arg0	/* points to arg7 */
 	ldi 1,%arg1		/* called with wide-bit cleared (narrow mode) */

 	loadgp
 	load32_firmware parisc_pdc_entry,%r1
 	load32	MEM_PDC_ENTRY + c64_32_return - pdc_entry_table,%rp
 	bv 0(%r1)
 	ldo FRAME_SIZE(%sp),%sp

 c64_32_return:
 	/* return from PDC call */
 	ldo -FRAME_SIZE(%sp),%sp
 	ldd -0x10(%sp),%rp
 	ldd -0x18(%sp),%dp
 	ldd -0x30(%sp),%arg2	/* addr of result buffer */
 	ldo -2*FRAME_SIZE(%sp),%sp /* restore original 32-bit stack */

 	cmpb,=,n %r0,%arg2,5f   /* skip copy results if target buffer is NULL */
 	cmpb,<   %ret0,%r0,5f	/* skip copy results if return value was negative (=error) */
 	ldi MEM_PDC_ENTRY,%r1
 	cmpb,>=,n %arg2,%r1,convert_ret64_buffer  /* copy results if target buffer >= MEM_PDC_ENTRY */
 	b,n .
 	.word 0xfffdead0	/* immediately halt the emulator */

 convert_ret64_buffer:
 	/* copy 64-bit-wide PDC result to 32-bit wide results */
 	ldi 32,%r1
 	copy %arg2,%arg3
 .L1:	ldd,ma 8(%arg2),%arg1
 	stwm %arg1, 4(%arg3)
 	ldo -1(%r1),%r1
 	cmpb,>>,n %r1,%r0,.L1

 5:	/* return to caller */
 	clear_PSW_W
 	bv,n %r0(%rp)

 ENTRY(pdc_entry_64_64)	/* 64-bit call on 64-bit PDC */
 	ldo FRAME_SIZE(%sp),%sp
 	std %rp,-0x10(%sp)
 	std %dp,-0x18(%sp)
 	std %arg0,-0x20(%sp)
 	std %arg1,-0x28(%sp)
 	std %arg2,-0x30(%sp)
 	std %arg3,-0x38(%sp)
 	std %r22, -0x40(%sp)
 	std %r21, -0x48(%sp)
 	std %r20, -0x50(%sp)
 	std %r19, -0x58(%sp)
 	ldo -0x58(%sp),%arg0	/* points to arg7 */
 	ldi 0,%arg1		/* called with wide-bit set (not narrow) */

 	loadgp
 	b,l parisc_pdc_entry, %rp
 	ldo FRAME_SIZE(%sp),%sp

 	ldo -FRAME_SIZE(%sp),%sp
 	ldd -0x10(%sp),%rp
 	ldd -0x18(%sp),%dp
 	bv  %r0(%rp)
 	ldo -FRAME_SIZE(%sp),%sp
 END(pdc_entry_64_32)
 #endif


 ENTRY(iodc_entry_table)
 	load32 parisc_iodc_ENTRY_INIT,   %r1
 iodc_entry_table_one_entry:
 	.export iodc_entry_table_one_entry
 	load32 parisc_iodc_ENTRY_IO,     %r1
 	load32 parisc_iodc_ENTRY_SPA,    %r1
 	load32 parisc_iodc_ENTRY_CONFIG, %r1
 	load32 hlt,			 %r1 /* obsolete */
 	load32 parisc_iodc_ENTRY_TEST,   %r1
 	load32 parisc_iodc_ENTRY_TLB,    %r1
 END(iodc_entry_table)

 /* the code for iodc_entry[] will be copied to user.
    the first load32* wil be replaced by an entry from
    the iodc_entry_table[] table above. */
 ENTRY(iodc_entry)
 	/* this first call we be replaced at runtime: */
 	load32 parisc_iodc_ENTRY_IO, %r1

 #ifdef CONFIG_64BIT
 	addb,*>,n %r0,%r0,iodc_narrow /* branch if narrow addressing */
 	nop
 #if 1
 	// HALT
 	load32_firmware hlt,%r1
 	bv,n %r0(%r1)
 #endif
 	b,n iodc_wide

 iodc_narrow:
 	/* we run narrow, but want wide! Jump to firmware to set PSW.W=1 */
 	/* Switch to wide mode. */
 	load32		MEM_PDC_ENTRY + 2f - pdc_entry_table,%r31
 	bv              0(%r31)
 	set_PSW_W
 2:	/* now in wide mode, running in low memory */
 	depdi   0, 31, 32, %sp
 	load_fw_upper32 %r1

 	stw %rp,-20(%sp)
 	stw %dp,-32(%sp)
 	stw %arg0,-36(%sp)
 	stw %arg1,-40(%sp)
 	stw %arg2,-44(%sp)
 	stw %arg3,-48(%sp)
 	ldo -FRAME_SIZE32(%sp),%arg0
 	loadgp
 	load32	MEM_PDC_ENTRY +  .iodc_ret32 - pdc_entry_table,%rp
 	bv %r0(%r1)
 	ldo 2*FRAME_SIZE(%sp),%sp
 .iodc_ret32:
 	ldo -2*FRAME_SIZE(%sp),%sp
 	ldw -20(%sp),%rp
 	ldw -32(%sp),%dp
 	bv   %r0(%rp)
 	clear_PSW_W
 	/* END for 32-bit IODC call */

 iodc_narrow_jump_to_firmware:
 	/* clear upper bits */
 	depdi   0, 31, 32, %rp
 	depdi   0, 31, 32, %dp
 	depdi   0, 31, 32, %arg0
 	depdi   0, 31, 32, %arg1
 	depdi   0, 31, 32, %arg2
 	depdi   0, 31, 32, %arg3
 	depdi   0, 31, 32, %r22
 	depdi   0, 31, 32, %r21
 	depdi   0, 31, 32, %r20
 	depdi   0, 31, 32, %r19
 iodc_wide:
 	std %rp,-0x10(%sp)
 	std %dp,-0x18(%sp)
 	std %arg0,-0x20(%sp)
 	std %arg1,-0x28(%sp)
 	std %arg2,-0x30(%sp)
 	std %arg3,-0x38(%sp)
 	std %r22, -0x40(%sp)
 	std %r21, -0x48(%sp)
 	std %r20, -0x50(%sp)
 	std %r19, -0x58(%sp)
 	ldo -0x58(%sp),%arg0	/* points to arg7 */
 #else
 	stw %rp,-20(%sp)
 	stw %dp,-32(%sp)
 	stw %arg0,-36(%sp)
 	stw %arg1,-40(%sp)
 	stw %arg2,-44(%sp)
 	stw %arg3,-48(%sp)
 	ldo -FRAME_SIZE(%sp),%arg0
 #endif

 	loadgp
 	load32 .iodc_ret, %rp
 	bv %r0(%r1)
 	ldo FRAME_SIZE(%sp),%sp
 .iodc_ret:
 	ldo -FRAME_SIZE(%sp),%sp
 #ifdef CONFIG_64BIT
 	ldd -0x10(%sp),%rp
 	ldd -0x18(%sp),%dp
 #else
 	ldw -20(%sp),%rp
 	ldw -32(%sp),%dp
 #endif
 	bv   %r0(%rp)
 	clear_PSW_W
 END(iodc_entry)

 /* PDC is copied up until here: */
 pdc_entry_table_end:
 	.export pdc_entry_table_end

 /****************************************************************
  * Rom Header for VGA / STI
  ****************************************************************/

 #if 0 // def CONFIG_BUILD_VGABIOS

         .section .rom.header
         .global _rom_header, _rom_header_size, _rom_header_checksum
 _rom_header:
         .word 0xaa55
 _rom_header_size:
         .byte 0
 _rom_header_entry:
         .word _optionrom_entry  // b,n ?
 _rom_header_checksum:
         .byte 0
 _rom_header_other:
         .space 17
 _rom_header_pcidata:
 #if CONFIG_VGA_PCI == 1
         .word rom_pci_data
 #else
         .word 0
 #endif
 _rom_header_pnpdata:
         .word 0
 _rom_header_other2:
         .word 0
 _rom_header_signature:
         .asciz "IBM"


 ENTRY(_optionrom_entry)
 	.import vga_post
 	load32 BOOTADDR(vga_post), %r1
 	bv,n %r0(%r1)
 END(_optionrom_entry)

 #endif /* CONFIG_BUILD_VGABIOS */
	/*
	* Startup glue code for parisc firmware
	*
	* (C) 2017-2024 Helge Deller <deller@gmx.de>
	*/

	#include "parisc/hppa.h"
	#include "parisc/hppa_hardware.h"
	#include "parisc/pdc.h"
	#include "autoconf.h"
	#include "autoversion.h"

	/* load 32-bit 'value' into 'reg' with
	sign-extension when running in wide mode. */
	.macro load32_sign_extend value, reg
	ldil L%\value, \reg
	ldo R%\value(\reg), \reg
	.endm

	/* load 32-bit 'value' into 'reg' compensating for the ldil
	* sign-extension when running in wide mode. */
	.macro load32 value, reg
	ldil L%\value, \reg
	ldo R%\value(\reg), \reg
	#ifdef CONFIG_64BIT
	depdi 0, 31, 32, \reg
	#endif
	.endm

	/* set upper 32-bits of firmware address */
	.macro load_fw_upper32 reg
	#ifdef CONFIG_64BIT
	depdi FIRMWARE_HIGH, 31, 32, \reg
	#endif
	.endm

	.macro load32_firmware value, reg
	ldil L%\value, \reg
	ldo R%\value(\reg), \reg
	#ifdef CONFIG_64BIT
	depdi FIRMWARE_HIGH, 31, 32, \reg
	#endif
	.endm

	;! set the W bit
	#define set_PSW_W .level 2.0 ! ssm PSW_W_SM, %r0 ! .level LEVEL

	;! nuke the W bit
	#define clear_PSW_W .level 2.0 ! rsm PSW_W_SM, %r0 ! .level LEVEL

	#define ENTRY(name) \
	.export name !\
	.align 4 !\
	name:

	#define END(name) \
	.size name, .-name

	#define ENDPROC(name) \
	.type name, @function !\
	END(name)

	#define BOOTADDR(x) (x)

	.macro loadgp
	#ifdef CONFIG_64BIT
	ldil L%__gp, %r27
	ldo R%__gp(%r27), %r27
	load_fw_upper32 %r27
	#else
	ldil L%$global$, %r27
	ldo R%$global$(%r27), %r27
	#endif
	.endm

	#ifdef CONFIG_64BIT
	#define LEVEL 2.0w
	#define LDREG ldd
	#define STREG std
	#define LDREGX ldd,s
	#define LDREGM ldd,mb
	#define STREGM std,ma
	#define SHRREG shrd
	#define SHLREG shld
	#define ANDCM andcm,*
	#define COND(x) * ## x
	#define FRAME_SIZE 128
	#define FRAME_SIZE32 64
	#define CALLEE_REG_FRAME_SIZE 144
	#define ASM_ULONG_INSN .dword
	#define WORD_LEN 8
	#define INT_LEN 4
	#else /* CONFIG_64BIT */
	#define LEVEL 1.1
	#define LDREG ldw
	#define STREG stw
	#define LDREGX ldwx,s
	#define LDREGM ldwm
	#define STREGM stwm
	#define SHRREG shr
	#define SHLREG shlw
	#define ANDCM andcm
	#define COND(x) x
	#define FRAME_SIZE 64
	#define CALLEE_REG_FRAME_SIZE 128
	#define ASM_ULONG_INSN .word
	#define WORD_LEN 4
	#define INT_LEN 4
	#endif

	/* various control register and irq bits */
	#define PSW_I 1
	#define PSW_Q 8
	#define CR_EIRR 23
	#define CR_IVA 14
	#define CR_EIEM 15
	#define PSW_W_SM 0x200
	#define PSW_W_BIT 36

	.import $global$
	.section ".head.text","ax"
	.level LEVEL

	/* On HPMC, the CPUs will start here at 0xf0000000 */
	hpmc_entry:
	b,n toc_asm_entry /* TOC and HPMC */

	reset_entry:
	/* at reset, the CPU begins fetching instructions from address 0xf0000004. */
	b,n startup

	marker:
	/* file identification, useful for strings command on binary file to see version. */
	.stringz "PA-RISC/HPPA PDC Firmware " SEABIOS_HPPA_VERSION_STR " (SeaBIOS fork)"
	.stringz "https://github.com/hdeller/seabios-hppa"
	.stringz BUILD_VERSION

	/*******************************************************
	Firmware startup code
	*******************************************************/

	.align 0x80
	ENTRY(startup)
	rsm PSW_I, %r0 /* disable local irqs */
	ssm PSW_Q, %r0 /* enable PSW_Q flag */

	#ifdef CONFIG_64BIT
	/* check if we really run on 64-bit CPU */
	ldo -1(%r0), %r1
	mtctl %r1,%cr11
	mfctl,w %cr11, %r1
	ldo -31(%r1),%r1
	cmpib,<>,n 0,%r1,1f
	.word 0xfffdead0 /* immediately halt the emulator */
	1:
	/* we now know we run on a 64-bit CPU. */
	/* next step: turn on the PSW.W flag (enable 64-bit mode) */
	load32 2f,%r11
	load_fw_upper32 %r11

	mtctl %r0,%cr17 /* Clear IIASQ tail */
	mtctl %r0,%cr17 /* Clear IIASQ head */

	/* Load RFI target into PC queue */
	mtctl %r11,%cr18 /* IIAOQ head */
	ldo 4(%r11),%r11
	mtctl %r11,%cr18 /* IIAOQ tail */

	load32 (0x08000000 \| PSW_Q),%r10 /* PSW.W=1 */
	mtctl %r10,%ipsw

	/* Jump through hyperspace to enable PSW.W */
	rfi
	nop
	2:
	#else
	/* clear any PSW.W on 32-bit firmware */
	clear_PSW_W
	#endif

	/* Make sure space registers are set to zero */
	mtsp %r0,%sr0
	mtsp %r0,%sr1
	mtsp %r0,%sr2
	mtsp %r0,%sr3
	mtsp %r0,%sr4
	mtsp %r0,%sr5
	mtsp %r0,%sr6
	mtsp %r0,%sr7

	/* If CPU HPA is already set in CPU_HPA_CR_REG then the
	* CPU is already initialized and the machine was only reset */
	mfctl CPU_HPA_CR_REG, %r1
	comib,= 0,%r1,$startup_fresh_booted
	nop

	$startup_just_rebooted:
	/* Get current CPU HPA. It was stored there at initial bootup. */
	mfctl CPU_HPA_CR_REG, %r5

	/* branch if this is the monarch cpu */
	load32_sign_extend CPU_HPA, %r1
	comb,=,n %r5,%r1,$is_monarch_cpu_reboot

	b,n enter_smp_idle_loop

	$startup_fresh_booted:
	/* Here the machine was booted from scratch: */

	/* Save CPU HPA in cr7, hopefully HP-UX will not use that register. */
	#ifdef CONFIG_64BIT
	extrw,s,>= %r5,31,32,%r5 /* sign extend CPU HPA */
	#endif
	mtctl %r5, CPU_HPA_CR_REG /* store CPU HPA */

	/* branch if this is the monarch cpu */
	load32_sign_extend CPU_HPA,%r1
	comb,= %r5,%r1,$is_monarch_cpu
	nop

	ENTRY(enter_smp_idle_loop)
	/* IDLE LOOP for SMP CPUs - wait for rendenzvous. */
	mfctl CPU_HPA_CR_REG, %r25 /* get CPU HPA from cr7 */

	rsm PSW_I, %r0 /* disable local irqs */
	mtctl %r0, CR_EIEM /* disable all external irqs */

	/* EIRR : clear all pending external intr */
	load32 -1,%r1
	mtctl %r1, CR_EIRR
	mfctl CR_EIRR, %r0
	mtctl %r0, CR_EIRR

	/* Load IVT for SMT tiny loop exit */
	load32_firmware BOOTADDR(smp_ivt),%r1
	mtctl %r1, CR_IVA

	/* enable CPU local interrupts */
	load32 1<<31, %r1 /* allow IRQ0 (Timer) */
	mtctl %r1, CR_EIEM
	ssm PSW_I, %r0 /* enable local irqs */

	/* endless idle loop for secondary CPUs. Exits to $smp_exit_loop by IRQ only */
	$smp_idle_loop:
	b $smp_idle_loop
	or %r10,%r10,%r10 /* qemu sleep instruction */

	$smp_exit_loop:
	rsm PSW_I, %r0 /* disable local irqs */
	mtctl %r0, CR_EIEM

	/* Load IVT to detect and report crashes */
	load32_firmware BOOTADDR(firmware_default_ivt),%r1
	mtctl %r1, CR_IVA

	/* provide PDCE_PROC entry in arg0 (required on 64-bit) */
	load32 MEM_PDC_ENTRY, %arg0

	/* jump to rendevouz */
	ldw 0x10(%r0),%r3 /* MEM_RENDEZ */
	#ifdef CONFIG_64BIT
	addb,>,n %r0,%r0,1f / branch if narrow addressing */
	ldw 0x28(%r0),%r1 /* MEM_RENDEZ_HI */
	depd %r1, 31, 32, %r3
	1:
	#endif
	cmpb,=,n %r0,%r3,enter_smp_idle_loop
	nop /* failed backward branch is nullified */
	load32_firmware startup, %rp
	bv,n 0(%r3)

	$is_monarch_cpu:
	/* Save boot_args in PAGE0->pad608[]. Only monarch CPU does this once. */
	load32 BOOTADDR(0x608),%r1
	STREGM %r26,WORD_LEN(%r1)
	STREGM %r25,WORD_LEN(%r1)
	STREGM %r24,WORD_LEN(%r1)
	STREGM %r23,WORD_LEN(%r1)
	STREGM %r22,WORD_LEN(%r1)
	STREGM %r21,WORD_LEN(%r1)
	STREGM %r20,WORD_LEN(%r1)
	STREGM %r19,WORD_LEN(%r1)

	$is_monarch_cpu_reboot:
	/* Initialize stack pointer */
	load32_firmware BOOTADDR(parisc_stack),%r1
	ldo FRAME_SIZE(%r1),%sp

	/* Initialize the global data pointer */
	loadgp

	/* Clear BSS on monarch CPU */
	.import _bss,data
	.import _ebss,data

	load32_firmware BOOTADDR(_bss),%r3
	load32_firmware BOOTADDR(_ebss),%r4
	$bss_loop:
	cmpb,<<,n %r3,%r4,$bss_loop
	STREGM %r0,WORD_LEN(%r3)

	/* Load IVT to detect and report crashes */
	load32_firmware BOOTADDR(firmware_default_ivt),%r1
	mtctl %r1, CR_IVA

	load32_firmware BOOTADDR(start_parisc_firmware),%r3
	bv 0(%r3)
	copy %r0,%r2
	END(startup)

	/*******************************************************/

	ENTRY(start_kernel)
	#ifdef CONFIG_64BIT
	bv 0(%r22)
	clear_PSW_W /* clear PSW before we start the kernel! */
	#else
	ldw -0x34(%sp),%r1
	bv,n 0(%r1)
	#endif
	END(start_kernel)

	/*******************************************************
	TOC handler
	Write all GRs, CRs, SRs and the iaoq_back and iasq_back registers (in
	r24/r25) into PIM area (when it's not filled yet). This is done by trashing the
	shadow registers.
	In a second step call the arificial getshadowregs asm instruction to restore
	the shadow registers to their real values and store them in PIM as well. Then
	call the C-code.
	*******************************************************/

	/* uses the shadow registers: 1,8,9,16,17,24,25 */
	#define PIM_PTR %r1
	#define TEMP %r8
	#define TEMP2 %r9
	#define PIM_SAVE %r16
	#define IASQ_BACK %r24 /* provided by qemu */
	#define IAOQ_BACK %r25 /* provided by qemu */

	.import pim_toc_data, data
	ENTRY(toc_asm_entry)
	/* serialize CPUs on entry */
	load32_firmware BOOTADDR(toc_lock),TEMP
	0: ldcw,co 0(TEMP),TEMP2
	cmpib,= 0,TEMP2,0b
	nop

	mfctl CPU_HPA_CR_REG, TEMP2 /* get CPU HPA from cr7 */
	extru TEMP2,31-12,4, TEMP /* extract cpu id */

	load32_firmware BOOTADDR(pim_toc_data), PIM_PTR

	1: comib,= 0,TEMP,2f
	ldo -1(TEMP),TEMP
	ldo (PIM_STORAGE_SIZE)(PIM_PTR), PIM_PTR /* find PIM entry */
	b 1b

	2: copy PIM_PTR, PIM_SAVE
	mtsp %r0,%sr0

	/* save registers into PIM only if cpu_state field is empty */
	ldw ((32+32+8+2)WORD_LEN + 1INT_LEN)(PIM_SAVE), TEMP
	comib,<>,n 0, TEMP, 5f

	/* save all general registers */
	.set loop,0
	.rept 32
	copy loop,TEMP
	STREGM TEMP, WORD_LEN(PIM_PTR)
	.set loop,loop+1
	.endr

	/* save all control registers */
	.set loop,0
	.rept 32
	mfctl loop,TEMP
	STREGM TEMP, WORD_LEN(PIM_PTR)
	.set loop,loop+1
	.endr

	/* save all space registers */
	.set loop,0
	.rept 8
	mfsp loop,TEMP
	STREGM TEMP, WORD_LEN(PIM_PTR)
	.set loop,loop+1
	.endr

	/* save IASQ_back and IAOQ_back as provided by qemu */
	STREG IASQ_BACK, ((32+32+8+0)*WORD_LEN)(PIM_SAVE)
	STREG IAOQ_BACK, ((32+32+8+1)*WORD_LEN)(PIM_SAVE)

	/* restore shadow registers, can not use PIM_SAVE reg for this */
	copy PIM_SAVE, %r26
	.word 0xfffdead2 /* qemu artificial getshadowregs asm instruction */
	STREG %r1, (1*WORD_LEN)(%r26)
	STREG %r8, (8*WORD_LEN)(%r26)
	STREG %r9, (9*WORD_LEN)(%r26)
	STREG %r16, (16*WORD_LEN)(%r26)
	STREG %r17, (17*WORD_LEN)(%r26)
	STREG %r24, (24*WORD_LEN)(%r26)
	STREG %r25, (25*WORD_LEN)(%r26)

	#ifdef CONFIG_64BIT
	/* cr11 (sar) is a funny one. 5 bits on PA1.1 and 6 bit on PA2.0
	* For PA2.0 mtsar or mtctl always write 6 bits, but mfctl only
	* reads 5 bits. Use mfctl,w to read all six bits. Otherwise
	* we lose the 6th bit on a save/restore. */
	mfctl,w %cr11, TEMP
	STREG TEMP, ((32+11)*WORD_LEN)(%r26)
	#endif

	5: /* call the "C" toc_handler in SeaBIOS */
	loadgp
	load32_firmware BOOTADDR(parisc_stack), %sp
	b,l toc_handler, %r2
	ldo FRAME_SIZE(%sp),%sp

	/* call OS handler, in case it returns reset the system */
	load32_firmware BOOTADDR(reset), %rp
	bv,n 0(%ret0)
	END(toc_asm_entry)


	/*******************************************************
	SMP Interrupt vector table (IVT)
	*******************************************************/

	.macro DEF_IVA_ENTRY
	.align 32
	load32_firmware BOOTADDR($smp_exit_loop),%r1
	bv 0(%r1)
	nop
	.endm

	.align 32 /* should be 4k aligned but qemu does not check */
	ENTRY(smp_ivt)
	.rept 32
	DEF_IVA_ENTRY
	.endr
	END(smp_ivt)

	/*******************************************************
	Fault detection & reporting Interrupt vector table (IVT)
	*******************************************************/

	/* fault happened at bootup. Return to instruction after fault. */
	ENTRY(fault_return_to_caller)
	mfctl %cr18,TEMP
	ldo 4(TEMP),TEMP
	mtctl TEMP,%cr18 /* IIAOQ head */
	ldo 4(TEMP),TEMP
	mtctl TEMP,%cr18 /* IIAOQ tail */
	rfi
	nop
	END(fault_return_to_caller)

	/* call firmware_fault_handler in parisc.c and halt. */
	ENTRY(fault_call_firmware)
	load32_firmware firmware_fault_handler,TEMP
	loadgp
	bv,n 0(TEMP)
	END(fault_call_firmware)

	.align 32
	ENTRY(firmware_default_ivt) /* to detect crashes */
	.set loop,0
	.import firmware_fault_handler,code
	.rept 32
	/* Make sure to use shadow registers only! */
	/* While booting up we check if various devices are available.
	Allow such checks and do not raise an HPMC. */
	ldi loop,TEMP /* trap# into TEMP */
	cmpib,= 1,TEMP,fault_return_to_caller
	nop
	b fault_call_firmware
	ldi loop,%arg0 /* trap# into arg0 */
	.set loop,loop+1
	.align 32
	.endr
	END(smp_ivt)


	/*******************************************************
	PDC and IODC entry
	*******************************************************/

	/* pdc_entry_table will be copied into low memory. */
	ENTRY(pdc_entry_table)
	#ifdef CONFIG_64BIT
	/* see section "Testing the Current State of the PSW W-Bit",
	page I-2 in parisc2 spec */
	addb,>,n %r0,%r0,pdc_called_narrow / branch if narrow addressing */

	pdc_called_wide:
	/* we know that PDC was called with PSW.W=1 */
	load32_firmware pdc_entry_64_64,%r1
	bv,n %r0(%r1)

	pdc_called_narrow:
	/* we know that PDC was called with PSW.W=0 */
	load32 MEM_PDC_ENTRY + pdc_entry_64_32 - pdc_entry_table,%r1
	bv 0(%r1)
	set_PSW_W /* enable PSW.W */
	#else
	ENTRY(pdc_entry_32) /* 32-bit PDC */
	stw %rp,-20(%sp)
	stw %dp,-32(%sp)
	stw %arg0,-36(%sp)
	stw %arg1,-40(%sp)
	stw %arg2,-44(%sp)
	stw %arg3,-48(%sp)
	ldo -FRAME_SIZE(%sp),%arg0
	ldi 1,%arg1 /* called with wide-bit cleared (narrow mode) */

	loadgp
	load32 MEM_PDC_ENTRY + 1f - pdc_entry_table,%rp
	load32 parisc_pdc_entry, %r1
	clear_PSW_W
	bv 0(%r1)
	ldo FRAME_SIZE(%sp),%sp
	1:
	ldo -FRAME_SIZE(%sp),%sp
	ldw -20(%sp),%rp
	ldw -32(%sp),%dp
	bv,n %r0(%rp)
	END(pdc_entry_32)
	#endif
	END(pdc_entry_table)

	#ifdef CONFIG_64BIT
	ENTRY(pdc_entry_64_32) /* 32-bit call on 64-bit PDC */
	/* clear upper bits */
	depdi 0, 31, 32, %sp
	depdi 0, 31, 32, %rp
	depdi 0, 31, 32, %dp
	depdi 0, 31, 32, %arg0
	depdi 0, 31, 32, %arg1
	depdi 0, 31, 32, %arg2
	depdi 0, 31, 32, %arg3

	copy %sp,%r1 /* copy original stack pointer */
	ldo 2FRAME_SIZE(%sp),%sp / build new 64-bit stack */

	std %rp,-0x10(%sp)
	std %dp,-0x18(%sp)
	std %arg0,-0x20(%sp)
	std %arg1,-0x28(%sp)
	std %arg2,-0x30(%sp)
	std %arg3,-0x38(%sp)

	ldw -FRAME_SIZE32 + 12(%r1),%arg0 /* ARG4 */
	depdi 0, 31, 32, %arg0
	std %arg0, -0x40(%sp)

	ldw -FRAME_SIZE32 + 8(%r1),%arg0 /* ARG5 */
	depdi 0, 31, 32, %arg0
	std %arg0, -0x48(%sp)

	ldw -FRAME_SIZE32 + 4(%r1),%arg0 /* ARG6 */
	depdi 0, 31, 32, %arg0
	std %arg0, -0x50(%sp)

	ldw -FRAME_SIZE32 + 0(%r1),%arg0 /* ARG7 */
	depdi 0, 31, 32, %arg0
	std %arg0, -0x58(%sp)

	ldo -0x58(%sp),%arg0 /* points to arg7 */
	ldi 1,%arg1 /* called with wide-bit cleared (narrow mode) */

	loadgp
	load32_firmware parisc_pdc_entry,%r1
	load32 MEM_PDC_ENTRY + c64_32_return - pdc_entry_table,%rp
	bv 0(%r1)
	ldo FRAME_SIZE(%sp),%sp

	c64_32_return:
	/* return from PDC call */
	ldo -FRAME_SIZE(%sp),%sp
	ldd -0x10(%sp),%rp
	ldd -0x18(%sp),%dp
	ldd -0x30(%sp),%arg2 /* addr of result buffer */
	ldo -2FRAME_SIZE(%sp),%sp / restore original 32-bit stack */

	cmpb,=,n %r0,%arg2,5f /* skip copy results if target buffer is NULL */
	cmpb,< %ret0,%r0,5f /* skip copy results if return value was negative (=error) */
	ldi MEM_PDC_ENTRY,%r1
	cmpb,>=,n %arg2,%r1,convert_ret64_buffer /* copy results if target buffer >= MEM_PDC_ENTRY */
	b,n .
	.word 0xfffdead0 /* immediately halt the emulator */

	convert_ret64_buffer:
	/* copy 64-bit-wide PDC result to 32-bit wide results */
	ldi 32,%r1
	copy %arg2,%arg3
	.L1: ldd,ma 8(%arg2),%arg1
	stwm %arg1, 4(%arg3)
	ldo -1(%r1),%r1
	cmpb,>>,n %r1,%r0,.L1

	5: /* return to caller */
	clear_PSW_W
	bv,n %r0(%rp)

	ENTRY(pdc_entry_64_64) /* 64-bit call on 64-bit PDC */
	ldo FRAME_SIZE(%sp),%sp
	std %rp,-0x10(%sp)
	std %dp,-0x18(%sp)
	std %arg0,-0x20(%sp)
	std %arg1,-0x28(%sp)
	std %arg2,-0x30(%sp)
	std %arg3,-0x38(%sp)
	std %r22, -0x40(%sp)
	std %r21, -0x48(%sp)
	std %r20, -0x50(%sp)
	std %r19, -0x58(%sp)
	ldo -0x58(%sp),%arg0 /* points to arg7 */
	ldi 0,%arg1 /* called with wide-bit set (not narrow) */

	loadgp
	b,l parisc_pdc_entry, %rp
	ldo FRAME_SIZE(%sp),%sp

	ldo -FRAME_SIZE(%sp),%sp
	ldd -0x10(%sp),%rp
	ldd -0x18(%sp),%dp
	bv %r0(%rp)
	ldo -FRAME_SIZE(%sp),%sp
	END(pdc_entry_64_32)
	#endif


	ENTRY(iodc_entry_table)
	load32 parisc_iodc_ENTRY_INIT, %r1
	iodc_entry_table_one_entry:
	.export iodc_entry_table_one_entry
	load32 parisc_iodc_ENTRY_IO, %r1
	load32 parisc_iodc_ENTRY_SPA, %r1
	load32 parisc_iodc_ENTRY_CONFIG, %r1
	load32 hlt, %r1 /* obsolete */
	load32 parisc_iodc_ENTRY_TEST, %r1
	load32 parisc_iodc_ENTRY_TLB, %r1
	END(iodc_entry_table)

	/* the code for iodc_entry[] will be copied to user.
	the first load32* wil be replaced by an entry from
	the iodc_entry_table[] table above. */
	ENTRY(iodc_entry)
	/* this first call we be replaced at runtime: */
	load32 parisc_iodc_ENTRY_IO, %r1

	#ifdef CONFIG_64BIT
	addb,>,n %r0,%r0,iodc_narrow / branch if narrow addressing */
	nop
	#if 1
	// HALT
	load32_firmware hlt,%r1
	bv,n %r0(%r1)
	#endif
	b,n iodc_wide

	iodc_narrow:
	/* we run narrow, but want wide! Jump to firmware to set PSW.W=1 */
	/* Switch to wide mode. */
	load32 MEM_PDC_ENTRY + 2f - pdc_entry_table,%r31
	bv 0(%r31)
	set_PSW_W
	2: /* now in wide mode, running in low memory */
	depdi 0, 31, 32, %sp
	load_fw_upper32 %r1

	stw %rp,-20(%sp)
	stw %dp,-32(%sp)
	stw %arg0,-36(%sp)
	stw %arg1,-40(%sp)
	stw %arg2,-44(%sp)
	stw %arg3,-48(%sp)
	ldo -FRAME_SIZE32(%sp),%arg0
	loadgp
	load32 MEM_PDC_ENTRY + .iodc_ret32 - pdc_entry_table,%rp
	bv %r0(%r1)
	ldo 2*FRAME_SIZE(%sp),%sp
	.iodc_ret32:
	ldo -2*FRAME_SIZE(%sp),%sp
	ldw -20(%sp),%rp
	ldw -32(%sp),%dp
	bv %r0(%rp)
	clear_PSW_W
	/* END for 32-bit IODC call */

	iodc_narrow_jump_to_firmware:
	/* clear upper bits */
	depdi 0, 31, 32, %rp
	depdi 0, 31, 32, %dp
	depdi 0, 31, 32, %arg0
	depdi 0, 31, 32, %arg1
	depdi 0, 31, 32, %arg2
	depdi 0, 31, 32, %arg3
	depdi 0, 31, 32, %r22
	depdi 0, 31, 32, %r21
	depdi 0, 31, 32, %r20
	depdi 0, 31, 32, %r19
	iodc_wide:
	std %rp,-0x10(%sp)
	std %dp,-0x18(%sp)
	std %arg0,-0x20(%sp)
	std %arg1,-0x28(%sp)
	std %arg2,-0x30(%sp)
	std %arg3,-0x38(%sp)
	std %r22, -0x40(%sp)
	std %r21, -0x48(%sp)
	std %r20, -0x50(%sp)
	std %r19, -0x58(%sp)
	ldo -0x58(%sp),%arg0 /* points to arg7 */
	#else
	stw %rp,-20(%sp)
	stw %dp,-32(%sp)
	stw %arg0,-36(%sp)
	stw %arg1,-40(%sp)
	stw %arg2,-44(%sp)
	stw %arg3,-48(%sp)
	ldo -FRAME_SIZE(%sp),%arg0
	#endif

	loadgp
	load32 .iodc_ret, %rp
	bv %r0(%r1)
	ldo FRAME_SIZE(%sp),%sp
	.iodc_ret:
	ldo -FRAME_SIZE(%sp),%sp
	#ifdef CONFIG_64BIT
	ldd -0x10(%sp),%rp
	ldd -0x18(%sp),%dp
	#else
	ldw -20(%sp),%rp
	ldw -32(%sp),%dp
	#endif
	bv %r0(%rp)
	clear_PSW_W
	END(iodc_entry)

	/* PDC is copied up until here: */
	pdc_entry_table_end:
	.export pdc_entry_table_end

	/****************************************************************
	* Rom Header for VGA / STI
	****************************************************************/

	#if 0 // def CONFIG_BUILD_VGABIOS

	.section .rom.header
	.global _rom_header, _rom_header_size, _rom_header_checksum
	_rom_header:
	.word 0xaa55
	_rom_header_size:
	.byte 0
	_rom_header_entry:
	.word _optionrom_entry // b,n ?
	_rom_header_checksum:
	.byte 0
	_rom_header_other:
	.space 17
	_rom_header_pcidata:
	#if CONFIG_VGA_PCI == 1
	.word rom_pci_data
	#else
	.word 0
	#endif
	_rom_header_pnpdata:
	.word 0
	_rom_header_other2:
	.word 0
	_rom_header_signature:
	.asciz "IBM"


	ENTRY(_optionrom_entry)
	.import vga_post
	load32 BOOTADDR(vga_post), %r1
	bv,n %r0(%r1)
	END(_optionrom_entry)

	#endif /* CONFIG_BUILD_VGABIOS */