ofw_subr.S revision 1.14
1 /* $NetBSD: ofw_subr.S,v 1.14 2021/02/18 16:29:12 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 /* OpenFirmware SR save area */ 51 .lcomm ofwsrsave,64,4 52 53 /* MSR and SPRG[0-3] used in OpenFirmware */ 54 .globl ofwmsr 55 .comm ofwmsr,20,4 56 57 /* 58 * Called by start to save the initial OFW state so we can restore it 59 * when call back to OFW. 60 * 61 * We expect the registers to be as for the entry point into the kernel: 62 * 63 * %r1 Stack provided by OpenFirmware / boot loader 64 * %r5 OpenFirmware client entry point 65 * 66 * (others -- don't care) 67 */ 68 ENTRY_NOPROFILE(ofwinit) 69 /* Save return address, Push a stack frame. */ 70 mflr %r0 71 stw %r0,4(%r1) 72 stwu %r1,-16(%r1) 73 74 #ifdef FIRMWORKSBUGS 75 mfmsr %r0 76 andi. %r0,%r0,PSL_IR|PSL_DR 77 beq 1f 78 79 li %r8,1 80 lis %r9,ofwreal_incharge@ha 81 stw %r8,ofwreal_incharge@l(%r9) 82 83 bl _C_LABEL(ofwr_init) 84 1: 85 #endif 86 87 lis %r8,ofentry@ha 88 stw %r5,ofentry@l(%r8) /* save client interface handler */ 89 90 /* 91 * Call directly into OpenFirmware until we're ready to use 92 * the trampoline. 93 */ 94 lis %r8,oftramp@ha 95 stw %r5,oftramp@l(%r8) 96 97 /* Save the MSR that OpenFirmware is using. */ 98 mfmsr %r0 99 lis %r9,ofwmsr@ha 100 stwu %r0,ofwmsr@l(%r9) 101 102 mfsprg0 %r0 /* save SPRGs */ 103 stw %r0,4(%r9) 104 mfsprg1 %r0 105 stw %r0,8(%r9) 106 mfsprg2 %r0 107 stw %r0,12(%r9) 108 mfsprg3 %r0 109 stw %r0,16(%r9) 110 111 lis %r8,OF_buffer@ha 112 addi %r8,%r8,OF_buffer@l 113 lis %r9,_C_LABEL(OF_buf)@ha 114 stw %r8,_C_LABEL(OF_buf)@l(%r9) 115 116 /* XXX Do other stuff in C code. */ 117 118 /* 119 * Jump off the trampoline for all subsequent calls 120 * into OpenFirmware. 121 */ 122 lis %r5,_C_LABEL(openfirmware_trampoline)@ha 123 addi %r5,%r5,_C_LABEL(openfirmware_trampoline)@l 124 lis %r8,oftramp@ha 125 stw %r5,oftramp@l(%r8) 126 127 /* Retrieve LR, pop stack frame. */ 128 addi %r1,%r1,16 129 lwz %r0,4(%r1) 130 mtlr %r0 131 132 blr 133 134 /* 135 * OpenFirmware trampoline. We are already on the OpenFirmware stack. 136 */ 137 ENTRY_NOPROFILE(openfirmware_trampoline) 138 mflr %r0 139 stw %r0,4(%r1) /* save return address */ 140 141 /* 142 * Push stack frame and save area: 143 * 144 * [SP+8 save area] 145 * [SP+4 slot for saved LR in callee] 146 * [SP+0 saved SP] 147 */ 148 stwu %r1,-48(%r1) 149 150 lis %r4,ofentry@ha /* get firmware entry point */ 151 lwz %r4,ofentry@l(%r4) 152 mtlr %r4 153 154 mfsprg0 %r5 /* save current sprg0 (curcpu) */ 155 stw %r5,16(%r1) 156 mfsprg1 %r5 /* save current sprg1 */ 157 stw %r5,20(%r1) 158 mfsprg2 %r5 /* save current sprg1 */ 159 stw %r5,24(%r1) 160 mfsprg3 %r5 /* save current sprg3 */ 161 stw %r5,28(%r1) 162 163 #ifdef FIRMWORKSBUGS 164 lis %r4,ofwreal_incharge@ha 165 lwz %r4,ofwreal_incharge@l(%r4) 166 cmpwi %r4,1 167 bne 1f 168 blrl 169 b 4f 170 1: 171 #endif 172 mfmsr %r4 /* save msr */ 173 stw %r4,8(%r1) 174 175 li %r0,0 /* clear battable translations */ 176 mtmsr %r0 177 #if defined (PPC_OEA) || defined (PPC_OEA64_BRIDGE) 178 mtdbatu 2,%r0 179 mtdbatu 3,%r0 180 mtibatu 2,%r0 181 mtibatu 3,%r0 182 #endif /* PPC_OEA */ 183 184 lis %r4,ofwsrsave@ha /* save current SRs */ 185 addi %r4,%r4,ofwsrsave@l 186 li %r5,0 187 1: mfsrin %r0,%r5 188 stw %r0,0(%r4) 189 addi %r4,%r4,4 190 addis %r5,%r5,0x10000000@h 191 cmpwi %r5,0 192 bne 1b 193 194 lis %r4,_C_LABEL(ofw_pmap)@ha /* load OFW SR */ 195 addi %r4,%r4,_C_LABEL(ofw_pmap)@l 196 lwz %r0,PM_KERNELSR(%r4) 197 cmpwi %r0,0 /* pm_sr[KERNEL_SR] == 0? */ 198 beq 2f /* then skip (not initialized yet) */ 199 li %r5,0 200 1: lwz %r0,0(%r4) 201 mtsrin %r0,%r5 202 addi %r4,%r4,4 203 addis %r5,%r5,0x10000000@h 204 cmpwi %r5,0 205 bne 1b 206 2: 207 lis %r4,ofwmsr+16@ha /* Open Firmware msr + sprg[0-3] */ 208 lwzu %r5,ofwmsr+16@l(%r4) 209 mtsprg3 %r5 210 lwz %r5,-4(%r4) 211 mtsprg2 %r5 212 lwz %r5,-8(%r4) 213 mtsprg1 %r5 214 lwz %r5,-12(%r4) 215 mtsprg0 %r5 216 lwz %r5,-16(%r4) 217 mtmsr %r5 218 isync 219 220 blrl /* call Open Firmware */ 221 222 lis %r4,ofwsrsave@ha /* restore saved SRs */ 223 addi %r4,%r4,ofwsrsave@l 224 li %r5,0 225 1: lwz %r0,0(%r4) 226 mtsrin %r0,%r5 227 addi %r4,%r4,4 228 addis %r5,%r5,0x10000000@h 229 cmpwi %r5,0 230 bne 1b 231 232 lwz %r4,8(%r1) /* restore msr */ 233 mtmsr %r4 234 isync 235 4: 236 lwz %r5,16(%r1) /* restore saved sprgs (curcpu) */ 237 mtsprg0 %r5 238 lwz %r5,20(%r1) 239 mtsprg1 %r5 240 lwz %r5,24(%r1) 241 mtsprg2 %r5 242 lwz %r5,28(%r1) 243 mtsprg3 %r5 244 245 addi %r1,%r1,48 /* pop stack frame and save area */ 246 lwz %r0,4(%r1) /* return address */ 247 mtlr %r0 248 blr 249 250 /* 251 * Call into OpenFirmware. 252 */ 253 ENTRY_NOPROFILE(openfirmware) 254 mflr %r0 255 stw %r0,4(%r1) /* save return address */ 256 257 /* Switch to OpenFirmware stack. */ 258 lis %r7,firmstk+NBPG-16@ha 259 addi %r7,%r7,firmstk+NBPG-16@l 260 stw %r1,0(%r7) /* stash away prev stack pointer */ 261 mr %r1,%r7 262 263 lis %r4,oftramp@ha 264 lwz %r4,oftramp@l(%r4) 265 266 mtctr %r4 267 bctrl 268 269 lwz %r1,0(%r1) /* restore previous stack pointer */ 270 lwz %r0,4(%r1) /* return address */ 271 mtlr %r0 272 blr 273
Indexes created Sun Oct 19 02:09:48 GMT 2025