/* $NetBSD: ofw_subr.S,v 1.21 2026/06/30 23:59:47 rkujawa Exp $ */ /* * Copyright (C) 1995, 1996 Wolfgang Solfrank. * Copyright (C) 1995, 1996 TooLs GmbH. * All rights reserved. * * Redistribution and use in source and binary forms, with or without * modification, are permitted provided that the following conditions * are met: * 1. Redistributions of source code must retain the above copyright * notice, this list of conditions and the following disclaimer. * 2. Redistributions in binary form must reproduce the above copyright * notice, this list of conditions and the following disclaimer in the * documentation and/or other materials provided with the distribution. * 3. All advertising materials mentioning features or use of this software * must display the following acknowledgement: * This product includes software developed by TooLs GmbH. * 4. The name of TooLs GmbH may not be used to endorse or promote products * derived from this software without specific prior written permission. * * THIS SOFTWARE IS PROVIDED BY TOOLS GMBH ``AS IS'' AND ANY EXPRESS OR * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. * IN NO EVENT SHALL TOOLS GMBH BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, * PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; * OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, * WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR * OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF * ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. */ #ifdef _KERNEL_OPT #include "opt_ppcarch.h" #include "opt_efika.h" #endif /* Stack used to call into OpenFirmware. */ .lcomm firmstk,NBPG,16 /* Buffer used to pass data to/from OpenFirmware. */ .lcomm OF_buffer,NBPG + 36,4 /* The OpenFirmware entry point, provided by OpenFirmware. */ .lcomm ofentry,4,4 /* Entry trampoline used by openfirmware(). */ .lcomm oftramp,4,4 /* Client SR save area */ .lcomm clsrsave,64,4 /* MSR used in OpenFirmware */ .globl ofwmsr .comm ofwmsr,4,4 #ifdef FIRMWORKSBUGS .lcomm ofwreal_incharge,4,4 #endif /* * Called by start to save the initial OFW state so we can restore it * when call back to OFW. * * We expect the registers to be as for the entry point into the kernel: * * %r1 Stack provided by OpenFirmware / boot loader * %r5 OpenFirmware client entry point * * (others -- don't care) */ ENTRY_NOPROFILE(ofwinit) /* Save return address, Push a stack frame. */ mflr %r0 stw %r0,4(%r1) stwu %r1,-16(%r1) #ifdef FIRMWORKSBUGS mfmsr %r0 andi. %r0,%r0,PSL_IR|PSL_DR beq 1f li %r8,1 lis %r9,ofwreal_incharge@ha stw %r8,ofwreal_incharge@l(%r9) bl _C_LABEL(ofwr_init) 1: #endif lis %r8,ofentry@ha stw %r5,ofentry@l(%r8) /* save client interface handler */ /* * Call directly into OpenFirmware until we're ready to use * the trampoline. */ lis %r8,oftramp@ha stw %r5,oftramp@l(%r8) /* Save the MSR that OpenFirmware is using. */ mfmsr %r0 lis %r9,ofwmsr@ha stw %r0,ofwmsr@l(%r9) lis %r8,OF_buffer@ha addi %r8,%r8,OF_buffer@l lis %r9,_C_LABEL(OF_buf)@ha stw %r8,_C_LABEL(OF_buf)@l(%r9) /* * Call into C code to perform additional early initialization. */ lis %r8,_C_LABEL(ofw_bootstrap)@ha addi %r8,%r8,_C_LABEL(ofw_bootstrap)@l mtctr %r8 bctrl /* * Jump off the trampoline for all subsequent calls * into OpenFirmware. */ lis %r5,_C_LABEL(openfirmware_trampoline)@ha addi %r5,%r5,_C_LABEL(openfirmware_trampoline)@l lis %r8,oftramp@ha stw %r5,oftramp@l(%r8) /* Retrieve LR, pop stack frame. */ addi %r1,%r1,16 lwz %r0,4(%r1) mtlr %r0 blr /* * OpenFirmware trampoline. We are already on the OpenFirmware stack. */ ENTRY_NOPROFILE(openfirmware_trampoline) mflr %r0 stw %r0,4(%r1) /* save return address */ /* * Push stack frame and save area: * * [SP+8 save area] * [SP+4 slot for saved LR in callee] * [SP+0 saved SP] */ stwu %r1,-48(%r1) #ifdef FIRMWORKSBUGS lis %r4,ofwreal_incharge@ha lwz %r4,ofwreal_incharge@l(%r4) cmpwi %r4,1 bne 1f blrl b 4f 1: #endif mfmsr %r4 /* save msr */ stw %r4,8(%r1) li %r0,0 /* disable MMU */ mtmsr %r0 isync #if defined (PPC_OEA) || defined (PPC_OEA64_BRIDGE) #ifdef EFIKA_OFW_WORKAROUNDS /* * EFIKA 5200B / CodeGen SmartFirmware call workarounds. * * Save SDR1. */ mfsdr1 %r4 stw %r4,12(%r1) #else /* clear BAT translations */ mtdbatu 2,%r0 mtdbatu 3,%r0 mtibatu 2,%r0 mtibatu 3,%r0 #endif /* EFIKA_OFW_WORKAROUNDS */ #endif /* PPC_OEA */ lis %r4,clsrsave@ha /* save current SRs */ addi %r4,%r4,clsrsave@l li %r5,0 1: mfsrin %r0,%r5 stw %r0,0(%r4) addi %r4,%r4,4 addis %r5,%r5,0x10000000@h cmpwi %r5,0 bne 1b lis %r4,_C_LABEL(ofw_pmap)@ha /* load OFW SR */ addi %r4,%r4,_C_LABEL(ofw_pmap)@l lwz %r0,PM_KERNELSR(%r4) cmpwi %r0,0 /* pm_sr[KERNEL_SR] == 0? */ beq 2f /* then skip (not initialized yet) */ li %r5,0 1: lwz %r0,0(%r4) mtsrin %r0,%r5 addi %r4,%r4,4 addis %r5,%r5,0x10000000@h cmpwi %r5,0 bne 1b 2: /* curcpu()->ci_battable = &ofw_battable */ GET_CPUINFO(%r4) lis %r5,_C_LABEL(ofw_battable)@ha addi %r5,%r5,_C_LABEL(ofw_battable)@l stw %r5,CI_BATTABLE(%r4) lis %r4,ofentry@ha /* get firmware entry point */ lwz %r4,ofentry@l(%r4) mtlr %r4 lis %r4,ofwmsr@ha /* load Open Firmware MSR */ lwz %r5,ofwmsr@l(%r4) mtmsr %r5 isync blrl /* call Open Firmware */ li %r0,0 /* ensure disable MMU is disabled */ mtmsr %r0 isync /* curcpu()->ci_battable = &battable */ GET_CPUINFO(%r4) lis %r5,_C_LABEL(battable)@ha addi %r5,%r5,_C_LABEL(battable)@l stw %r5,CI_BATTABLE(%r4) lis %r4,clsrsave@ha /* restore saved SRs */ addi %r4,%r4,clsrsave@l li %r5,0 1: lwz %r0,0(%r4) mtsrin %r0,%r5 addi %r4,%r4,4 addis %r5,%r5,0x10000000@h cmpwi %r5,0 bne 1b #if defined (PPC_OEA) || defined (PPC_OEA64_BRIDGE) #ifdef EFIKA_OFW_WORKAROUNDS /* * EFIKA 5200B / SmartFirmware: undo the firmware's leftover SDR1 zero * and user-valid BATs after the call. */ lwz %r4,12(%r1) /* restore kernel SDR1 (see save above) */ sync mtsdr1 %r4 isync mfibatu %r4,0 clrrwi %r4,%r4,1 /* clear Vp (BAT_Vu, bit 31) */ mtibatu 0,%r4 li %r4,0 mtibatu 1,%r4 mtibatu 2,%r4 mtibatu 3,%r4 isync mfdbatu %r4,0 clrrwi %r4,%r4,1 mtdbatu 0,%r4 mfdbatu %r4,1 clrrwi %r4,%r4,1 mtdbatu 1,%r4 mfdbatu %r4,2 clrrwi %r4,%r4,1 mtdbatu 2,%r4 mfdbatu %r4,3 clrrwi %r4,%r4,1 mtdbatu 3,%r4 isync #endif /* EFIKA_OFW_WORKAROUNDS */ #endif /* PPC_OEA */ lwz %r4,8(%r1) /* restore msr */ mtmsr %r4 isync 4: addi %r1,%r1,48 /* pop stack frame and save area */ lwz %r0,4(%r1) /* return address */ mtlr %r0 blr /* * Call into OpenFirmware. */ ENTRY_NOPROFILE(openfirmware) mflr %r0 stw %r0,4(%r1) /* save return address */ /* Switch to OpenFirmware stack. */ lis %r7,firmstk+NBPG-16@ha addi %r7,%r7,firmstk+NBPG-16@l stw %r1,0(%r7) /* stash away prev stack pointer */ mr %r1,%r7 lis %r4,oftramp@ha lwz %r4,oftramp@l(%r4) mtctr %r4 bctrl lwz %r1,0(%r1) /* restore previous stack pointer */ lwz %r0,4(%r1) /* return address */ mtlr %r0 blr
