126 lines
2.6 KiB
ArmAsm
126 lines
2.6 KiB
ArmAsm
/* $NetBSD: imx31lk_start.S,v 1.2 2008/04/27 18:58:46 matt Exp $ */
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#include <machine/asm.h>
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#include <arm/armreg.h>
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#include <arm/arm32/pmap.h>
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#include <arm/arm32/pte.h>
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/*
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*/
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#define CPWAIT_BRANCH \
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sub pc, pc, #4
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#define CPWAIT(tmp) \
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mrc p15, 0, tmp, c2, c0, 0 /* arbitrary read of CP15 */ ;\
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mov tmp, tmp /* wait for it to complete */ ;\
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CPWAIT_BRANCH /* branch to next insn */
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#ifndef SDRAM_START
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#define SDRAM_START 0x80000000
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#endif
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#define IXM31_DCACHE_SIZE 0x4000 /* 16KB L1 */
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.text
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.global _C_LABEL(imx31lk_start)
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_C_LABEL(imx31lk_start):
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/* Figure out where we want to jump to when the time comes */
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adr r8, .Lstart
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ldr r8, [r8]
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/*
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* set up virtual address space mapping
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* for initial bootstrap.
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*/
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mov r2, #(L1_S_SIZE) /* 1MB chunks */
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/*
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* Firmware already mapped SDRAM VA == PA. at 0x800..
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* now map SDRAM also at VA 0x800...
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*/
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mrc p15, 0, r0, c2, c0, 0 /* L1 addr into r0 */
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add r0, r0, #(0x800 * 4) /* offset to 0x80000000 */
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mov r3, #SDRAM_START /* map to 0x800.. */
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orr r3, r3, #(L1_S_AP(AP_KRW)) /* the usual perms & stuff */
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orr r3, r3, #(L1_TYPE_S)
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orr r3, r3, #(L1_S_DOM(PMAP_DOMAIN_KERNEL))
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mov r1, #0x80 /* 128 1MB entries */
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1:
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/* and looplooploop */
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str r3, [r0], #4
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add r3, r3, r2
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subs r1, r1, #1
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bgt 1b
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/*
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* Map an L1 section for each device to make this easy.
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*/
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/* UART1 */
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mrc p15, 0, r0, c2, c0, 0 /* Get L1 */
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add r0, r0, #(0xfd0 * 4) /* offset to 0xfd000000 */
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mov r3, #0x43000000
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orr r3, r3, #0x00f00000
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orr r3, r3, #(L1_S_AP(AP_KRW))
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orr r3, r3, #(L1_TYPE_S)
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orr r3, r3, #(L1_S_DOM(PMAP_DOMAIN_KERNEL))
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str r3, [r0], #4 /* note autoinc */
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/* etc, TBD... */
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/*
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* Make domain control go full art.
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*/
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mov r0, #0xffffffff
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mcr p15, 0, r0, c3, c0, 0
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/*
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* Now let's clean the cache again to make sure everything
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* is in place.
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*
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* XXX: should this take into account the XScale cache clean bug?
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*/
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mov r3, #(IXM31_DCACHE_SIZE)
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subs r3, r3, #32
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1:
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mcr p15, 0, r3, c7, c10, 2
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subs r3, r3, #32
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bne 1b
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CPWAIT(r3)
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/* Drain write buffer */
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mcr p15, 0, r6, c7, c10, 4
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/* Invalidate TLBs just to be sure */
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mcr p15, 0, r0, c8, c7, 0
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/*
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* You are standing at the gate to NetBSD. --More--
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* Unspeakable cruelty and harm lurk down there. --More--
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* Are you sure you want to enter?
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*/
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adr r8, .Lstart
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ldr r8, [r8]
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mov pc, r8 /* So be it */
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/* symbol to use for address calculation in the right VA */
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.Lstart:
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.word start
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/*
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* Calculate size of kernel to copy. Don't bother to copy bss,
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* although I guess the CPU could use the warmup exercise ...
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*/
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.Lcopy_size:
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.word _edata - _C_LABEL(imx31lk_start)
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