/* $NetBSD: sam460ex_locore.S,v 1.2 2026/06/18 23:18:24 rkujawa Exp $ */ /* * Copyright (c) 2012, 2014, 2024, 2026 The NetBSD Foundation, Inc. * All rights reserved. * * This code is derived from software contributed to The NetBSD Foundation * by Radoslaw Kujawa. * * 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. * * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``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 THE AUTHOR 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. */ /* * Copyright (c) 2009 KIYOHARA Takashi * 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. * * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``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 THE AUTHOR 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. */ /* * Kernel entry for the ACube Sam460ex (AMCC 460EX) * * Work with U-Boot (bootm) or qemu-system-ppc -M sam460ex -kernel * * r3 = physical address of the flattened device tree * r6 = ePAPR magic (0x45504150) * * Boot TLB layout (TID=0, matches any PID): * slot 0: 256MB VA 0x00000000 -> PA 0x0_00000000, cached (TS=0) * slot 1: 16MB VA 0xef000000 -> PA 0x4_ef000000, I+G (TS=0) * * TS=1 (KERNEL_PID) entries are pinned later by initppc() via * ppc44x_tlb_reserve(). */ #include "opt_ddb.h" #include "opt_ppcarch.h" #include "opt_ppcparam.h" #include "assym.h" #include "ksyms.h" #include <machine/param.h> #include <machine/psl.h> #include <machine/trap.h> #include <machine/asm.h> #include <powerpc/ibm4xx/spr.h> #include <powerpc/ibm4xx/tlb.h> .text .globl _C_LABEL(kernel_text) _C_LABEL(kernel_text): .text .globl __start __start: mr %r25, %r3 /* FDT physical address */ mr %r24, %r6 /* ePAPR magic */ li %r0, 0 mtmsr %r0 /* EE/CE/ME off, TS=0 */ isync /* Invalidate L1 caches (whole-cache forms on 440) */ iccci %r0, %r0 dccci %r0, %r0 sync isync /* Enable the FPU. */ mfspr %r3, SPR_CCR0 lis %r4, 0x0010 /* CCR0[DAPUIB], bit 11 = 0x00100000 */ andc %r3, %r3, %r4 mtspr SPR_CCR0, %r3 isync /* TLB writes below tag entries with MMUCR[STID]; want TID=0 */ li %r0, 0 mtspr SPR_MMUCR, %r0 isync /* * Temporary 16MB identity entry at EPN 0 in TS=1 */ li %r3, 0x0370 /* w0: EPN 0 | V | TS | 16MB */ li %r4, 0 /* w1: RPN 0, ERPN 0 */ li %r5, 0x0007 /* w2: SX | SW | SR, cached */ li %r6, 63 tlbwe %r5, %r6, 2 tlbwe %r4, %r6, 1 tlbwe %r3, %r6, 0 isync lis %r3, 1f@ha addi %r3, %r3, 1f@l mtsrr0 %r3 li %r4, (PSL_IS | PSL_DS)@l mtsrr1 %r4 rfi 1: /* Running in TS=1. Invalidate every TLB entry except slot 63. */ li %r3, 0 li %r4, 0 2: cmpwi %r4, 63 beq 3f tlbwe %r3, %r4, 0 3: addi %r4, %r4, 1 cmpwi %r4, 64 blt 2b sync isync /* pinned TS=0 entries. */ /* slot 0: 256MB RAM identity, cached */ li %r6, 0 li %r3, 0x0290 /* w0: EPN 0 | V | 256MB, TS=0 */ li %r4, 0 /* w1: RPN 0, ERPN 0 */ li %r5, 0x0007 /* w2: SX | SW | SR */ tlbwe %r5, %r6, 2 tlbwe %r4, %r6, 1 tlbwe %r3, %r6, 0 /* slot 1: 16MB I/O at VA 0xef000000 -> PA 0x4ef000000 */ li %r6, 1 lis %r3, 0xef00 ori %r3, %r3, 0x0270 /* w0: EPN | V | 16MB, TS=0 */ lis %r4, 0xef00 ori %r4, %r4, 0x0004 /* w1: RPN | ERPN=4 */ li %r5, 0x0503 /* w2: I | G | SW | SR */ tlbwe %r5, %r6, 2 tlbwe %r4, %r6, 1 tlbwe %r3, %r6, 0 isync /* back to TS=0, drop the temporary entry. */ lis %r3, 4f@ha addi %r3, %r3, 4f@l mtsrr0 %r3 li %r4, 0 mtsrr1 %r4 rfi 4: li %r3, 0 li %r4, 63 tlbwe %r3, %r4, 0 sync isync /* get start of bss */ lis %r3, _C_LABEL(_edata)-4@ha addi %r3, %r3, _C_LABEL(_edata)-4@l /* get end of kernel memory */ lis %r8, _C_LABEL(end)@ha addi %r8, %r8, _C_LABEL(end)@l /* zero bss */ li %r4, 0 5: stwu %r4, 4(%r3) cmpw %r3, %r8 bne+ 5b #if NKSYMS || defined(DDB) || defined(MODULAR) /* If we had symbol table location we'd store it here and would've adjusted r8 here */ lis %r7, _C_LABEL(startsym)@ha addi %r7, %r7, _C_LABEL(startsym)@l stw %r8, 0(%r7) lis %r7, _C_LABEL(endsym)@ha addi %r7, %r7, _C_LABEL(endsym)@l stw %r8, 0(%r7) #endif /* Set kernel MMU context. */ li %r0, KERNEL_PID mtspr SPR_PID, %r0 sync INIT_CPUINFO(8,1,9,0) mr %r4, %r8 lis %r3, __start@ha addi %r3, %r3, __start@l mr %r5, %r25 /* FDT physical address */ mr %r6, %r24 /* ePAPR magic */ bl _C_LABEL(initppc) bl _C_LABEL(main) not_reached: b not_reached #include <powerpc/ibm4xx/4xx_locore.S>
