/* * armboot - Startup Code for XScale CPU-core * * Copyright (C) 1998 Dan Malek * Copyright (C) 1999 Magnus Damm * Copyright (C) 2000 Wolfgang Denk * Copyright (C) 2001 Alex Zuepke * Copyright (C) 2001 Marius Groger * Copyright (C) 2002 Alex Zupke * Copyright (C) 2002 Gary Jennejohn * Copyright (C) 2002 Kyle Harris * Copyright (C) 2003 Kai-Uwe Bloem * Copyright (C) 2003 Kshitij * Copyright (C) 2003 Richard Woodruff * Copyright (C) 2003 Robert Schwebel * Copyright (C) 2004 Texas Instruments * Copyright (C) 2010 Marek Vasut * * SPDX-License-Identifier: GPL-2.0+ */ #include #include #include /* ************************************************************************* * * Startup Code (reset vector) * * do important init only if we don't start from memory! * setup Memory and board specific bits prior to relocation. * relocate armboot to ram * setup stack * ************************************************************************* */ .globl reset reset: /* * set the cpu to SVC32 mode */ mrs r0,cpsr bic r0,r0,#0x1f orr r0,r0,#0xd3 msr cpsr,r0 #ifndef CONFIG_SKIP_LOWLEVEL_INIT bl cpu_init_crit #endif #ifdef CONFIG_CPU_PXA25X bl lock_cache_for_stack #endif bl _main /*------------------------------------------------------------------------------*/ .globl c_runtime_cpu_setup c_runtime_cpu_setup: #ifdef CONFIG_CPU_PXA25X /* * Unlock (actually, disable) the cache now that board_init_f * is done. We could do this earlier but we would need to add * a new C runtime hook, whereas c_runtime_cpu_setup already * exists. * As this routine is just a call to cpu_init_crit, let us * tail-optimize and do a simple branch here. */ b cpu_init_crit #else bx lr #endif /* ************************************************************************* * * CPU_init_critical registers * * setup important registers * setup memory timing * ************************************************************************* */ #if !defined(CONFIG_SKIP_LOWLEVEL_INIT) || defined(CONFIG_CPU_PXA25X) cpu_init_crit: /* * flush v4 I/D caches */ mov r0, #0 mcr p15, 0, r0, c7, c7, 0 /* Invalidate I+D+BTB caches */ mcr p15, 0, r0, c8, c7, 0 /* Invalidate Unified TLB */ /* * disable MMU stuff and caches */ mrc p15, 0, r0, c1, c0, 0 bic r0, r0, #0x00003300 @ clear bits 13:12, 9:8 (--VI --RS) bic r0, r0, #0x00000087 @ clear bits 7, 2:0 (B--- -CAM) orr r0, r0, #0x00000002 @ set bit 2 (A) Align mcr p15, 0, r0, c1, c0, 0 mov pc, lr /* back to my caller */ #endif /* !CONFIG_SKIP_LOWLEVEL_INIT || CONFIG_CPU_PXA25X */ /* * Enable MMU to use DCache as DRAM. * * This is useful on PXA25x and PXA26x in early bootstages, where there is no * other possible memory available to hold stack. */ #ifdef CONFIG_CPU_PXA25X .macro CPWAIT reg mrc p15, 0, \reg, c2, c0, 0 mov \reg, \reg sub pc, pc, #4 .endm lock_cache_for_stack: /* Domain access -- enable for all CPs */ ldr r0, =0x0000ffff mcr p15, 0, r0, c3, c0, 0 /* Point TTBR to MMU table */ ldr r0, =mmutable mcr p15, 0, r0, c2, c0, 0 /* Kick in MMU, ICache, DCache, BTB */ mrc p15, 0, r0, c1, c0, 0 bic r0, #0x1b00 bic r0, #0x0087 orr r0, #0x1800 orr r0, #0x0005 mcr p15, 0, r0, c1, c0, 0 CPWAIT r0 /* Unlock Icache, Dcache */ mcr p15, 0, r0, c9, c1, 1 mcr p15, 0, r0, c9, c2, 1 /* Flush Icache, Dcache, BTB */ mcr p15, 0, r0, c7, c7, 0 /* Unlock I-TLB, D-TLB */ mcr p15, 0, r0, c10, c4, 1 mcr p15, 0, r0, c10, c8, 1 /* Flush TLB */ mcr p15, 0, r0, c8, c7, 0 /* Allocate 4096 bytes of Dcache as RAM */ /* Drain pending loads and stores */ mcr p15, 0, r0, c7, c10, 4 mov r4, #0x00 mov r5, #0x00 mov r2, #0x01 mcr p15, 0, r0, c9, c2, 0 CPWAIT r0 /* 128 lines reserved (128 x 32bytes = 4096 bytes total) */ mov r0, #128 ldr r1, =0xfffff000 alloc: mcr p15, 0, r1, c7, c2, 5 /* Drain pending loads and stores */ mcr p15, 0, r0, c7, c10, 4 strd r4, [r1], #8 strd r4, [r1], #8 strd r4, [r1], #8 strd r4, [r1], #8 subs r0, #0x01 bne alloc /* Drain pending loads and stores */ mcr p15, 0, r0, c7, c10, 4 mov r2, #0x00 mcr p15, 0, r2, c9, c2, 0 CPWAIT r0 mov pc, lr .section .mmutable, "a" mmutable: .align 14 /* 0x00000000 - 0xffe00000 : 1:1, uncached mapping */ .set __base, 0 .rept 0xfff .word (__base << 20) | 0xc12 .set __base, __base + 1 .endr /* 0xfff00000 : 1:1, cached mapping */ .word (0xfff << 20) | 0x1c1e #endif /* CONFIG_CPU_PXA25X */