ofw_subr.S revision 1.12.2.1
1 /* $NetBSD: ofw_subr.S,v 1.12.2.1 2021/04/03 22:28:35 thorpej Exp $ */ 2 3 /* 4 * Copyright (C) 1995, 1996 Wolfgang Solfrank. 5 * Copyright (C) 1995, 1996 TooLs GmbH. 6 * All rights reserved. 7 * 8 * Redistribution and use in source and binary forms, with or without 9 * modification, are permitted provided that the following conditions 10 * are met: 11 * 1. Redistributions of source code must retain the above copyright 12 * notice, this list of conditions and the following disclaimer. 13 * 2. Redistributions in binary form must reproduce the above copyright 14 * notice, this list of conditions and the following disclaimer in the 15 * documentation and/or other materials provided with the distribution. 16 * 3. All advertising materials mentioning features or use of this software 17 * must display the following acknowledgement: 18 * This product includes software developed by TooLs GmbH. 19 * 4. The name of TooLs GmbH may not be used to endorse or promote products 20 * derived from this software without specific prior written permission. 21 * 22 * THIS SOFTWARE IS PROVIDED BY TOOLS GMBH ``AS IS'' AND ANY EXPRESS OR 23 * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES 24 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. 25 * IN NO EVENT SHALL TOOLS GMBH BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, 26 * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, 27 * PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; 28 * OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, 29 * WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR 30 * OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF 31 * ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. 32 */ 33 34 #ifdef _KERNEL_OPT 35 #include "opt_ppcarch.h" 36 #endif 37 38 /* Stack used to call into OpenFirmware. */ 39 .lcomm firmstk,NBPG,16 40 41 /* Buffer used to pass data to/from OpenFirmware. */ 42 .lcomm OF_buffer,NBPG + 36,4 43 44 /* The OpenFirmware entry point, provided by OpenFirmware. */ 45 .lcomm ofentry,4,4 46 47 /* Entry trampoline used by openfirmware(). */ 48 .lcomm oftramp,4,4 49 50 /* Client SR save area */ 51 .lcomm clsrsave,64,4 52 53 /* MSR used in OpenFirmware */ 54 .globl ofwmsr 55 .comm ofwmsr,4,4 56 57 #ifdef FIRMWORKSBUGS 58 .lcomm ofwreal_incharge,4,4 59 #endif 60 61 /* 62 * Called by start to save the initial OFW state so we can restore it 63 * when call back to OFW. 64 * 65 * We expect the registers to be as for the entry point into the kernel: 66 * 67 * %r1 Stack provided by OpenFirmware / boot loader 68 * %r5 OpenFirmware client entry point 69 * 70 * (others -- don't care) 71 */ 72 ENTRY_NOPROFILE(ofwinit) 73 /* Save return address, Push a stack frame. */ 74 mflr %r0 75 stw %r0,4(%r1) 76 stwu %r1,-16(%r1) 77 78 #ifdef FIRMWORKSBUGS 79 mfmsr %r0 80 andi. %r0,%r0,PSL_IR|PSL_DR 81 beq 1f 82 83 li %r8,1 84 lis %r9,ofwreal_incharge@ha 85 stw %r8,ofwreal_incharge@l(%r9) 86 87 bl _C_LABEL(ofwr_init) 88 1: 89 #endif 90 91 lis %r8,ofentry@ha 92 stw %r5,ofentry@l(%r8) /* save client interface handler */ 93 94 /* 95 * Call directly into OpenFirmware until we're ready to use 96 * the trampoline. 97 */ 98 lis %r8,oftramp@ha 99 stw %r5,oftramp@l(%r8) 100 101 /* Save the MSR that OpenFirmware is using. */ 102 mfmsr %r0 103 lis %r9,ofwmsr@ha 104 stw %r0,ofwmsr@l(%r9) 105 106 lis %r8,OF_buffer@ha 107 addi %r8,%r8,OF_buffer@l 108 lis %r9,_C_LABEL(OF_buf)@ha 109 stw %r8,_C_LABEL(OF_buf)@l(%r9) 110 111 /* 112 * Call into C code to perform additional early initialization. 113 */ 114 lis %r8,_C_LABEL(ofw_bootstrap)@ha 115 addi %r8,%r8,_C_LABEL(ofw_bootstrap)@l 116 mtctr %r8 117 bctrl 118 119 /* 120 * Jump off the trampoline for all subsequent calls 121 * into OpenFirmware. 122 */ 123 lis %r5,_C_LABEL(openfirmware_trampoline)@ha 124 addi %r5,%r5,_C_LABEL(openfirmware_trampoline)@l 125 lis %r8,oftramp@ha 126 stw %r5,oftramp@l(%r8) 127 128 /* Retrieve LR, pop stack frame. */ 129 addi %r1,%r1,16 130 lwz %r0,4(%r1) 131 mtlr %r0 132 133 blr 134 135 /* 136 * OpenFirmware trampoline. We are already on the OpenFirmware stack. 137 */ 138 ENTRY_NOPROFILE(openfirmware_trampoline) 139 mflr %r0 140 stw %r0,4(%r1) /* save return address */ 141 142 /* 143 * Push stack frame and save area: 144 * 145 * [SP+8 save area] 146 * [SP+4 slot for saved LR in callee] 147 * [SP+0 saved SP] 148 */ 149 stwu %r1,-48(%r1) 150 151 #ifdef FIRMWORKSBUGS 152 lis %r4,ofwreal_incharge@ha 153 lwz %r4,ofwreal_incharge@l(%r4) 154 cmpwi %r4,1 155 bne 1f 156 blrl 157 b 4f 158 1: 159 #endif 160 mfmsr %r4 /* save msr */ 161 stw %r4,8(%r1) 162 163 li %r0,0 /* disable MMU */ 164 mtmsr %r0 165 isync 166 167 #if defined (PPC_OEA) || defined (PPC_OEA64_BRIDGE) 168 /* clear BAT translations */ 169 mtdbatu 2,%r0 170 mtdbatu 3,%r0 171 mtibatu 2,%r0 172 mtibatu 3,%r0 173 #endif /* PPC_OEA */ 174 175 lis %r4,clsrsave@ha /* save current SRs */ 176 addi %r4,%r4,clsrsave@l 177 li %r5,0 178 1: mfsrin %r0,%r5 179 stw %r0,0(%r4) 180 addi %r4,%r4,4 181 addis %r5,%r5,0x10000000@h 182 cmpwi %r5,0 183 bne 1b 184 185 lis %r4,_C_LABEL(ofw_pmap)@ha /* load OFW SR */ 186 addi %r4,%r4,_C_LABEL(ofw_pmap)@l 187 lwz %r0,PM_KERNELSR(%r4) 188 cmpwi %r0,0 /* pm_sr[KERNEL_SR] == 0? */ 189 beq 2f /* then skip (not initialized yet) */ 190 li %r5,0 191 1: lwz %r0,0(%r4) 192 mtsrin %r0,%r5 193 addi %r4,%r4,4 194 addis %r5,%r5,0x10000000@h 195 cmpwi %r5,0 196 bne 1b 197 2: 198 /* curcpu()->ci_battable = &ofw_battable */ 199 GET_CPUINFO(%r4) 200 lis %r5,_C_LABEL(ofw_battable)@ha 201 addi %r5,%r5,_C_LABEL(ofw_battable)@l 202 stw %r5,CI_BATTABLE(%r4) 203 204 lis %r4,ofentry@ha /* get firmware entry point */ 205 lwz %r4,ofentry@l(%r4) 206 mtlr %r4 207 208 lis %r4,ofwmsr@ha /* load Open Firmware MSR */ 209 lwz %r5,ofwmsr@l(%r4) 210 mtmsr %r5 211 isync 212 213 blrl /* call Open Firmware */ 214 215 li %r0,0 /* ensure disable MMU is disabled */ 216 mtmsr %r0 217 isync 218 219 /* curcpu()->ci_battable = &battable */ 220 GET_CPUINFO(%r4) 221 lis %r5,_C_LABEL(battable)@ha 222 addi %r5,%r5,_C_LABEL(battable)@l 223 stw %r5,CI_BATTABLE(%r4) 224 225 lis %r4,clsrsave@ha /* restore saved SRs */ 226 addi %r4,%r4,clsrsave@l 227 li %r5,0 228 1: lwz %r0,0(%r4) 229 mtsrin %r0,%r5 230 addi %r4,%r4,4 231 addis %r5,%r5,0x10000000@h 232 cmpwi %r5,0 233 bne 1b 234 235 lwz %r4,8(%r1) /* restore msr */ 236 mtmsr %r4 237 isync 238 4: 239 addi %r1,%r1,48 /* pop stack frame and save area */ 240 lwz %r0,4(%r1) /* return address */ 241 mtlr %r0 242 blr 243 244 /* 245 * Call into OpenFirmware. 246 */ 247 ENTRY_NOPROFILE(openfirmware) 248 mflr %r0 249 stw %r0,4(%r1) /* save return address */ 250 251 /* Switch to OpenFirmware stack. */ 252 lis %r7,firmstk+NBPG-16@ha 253 addi %r7,%r7,firmstk+NBPG-16@l 254 stw %r1,0(%r7) /* stash away prev stack pointer */ 255 mr %r1,%r7 256 257 lis %r4,oftramp@ha 258 lwz %r4,oftramp@l(%r4) 259 260 mtctr %r4 261 bctrl 262 263 lwz %r1,0(%r1) /* restore previous stack pointer */ 264 lwz %r0,4(%r1) /* return address */ 265 mtlr %r0 266 blr 267
Indexes created Tue Oct 21 07:10:13 GMT 2025