blob: f72c1989f5f2f5934e7940490560a2eeac04bb0a [file] [log] [blame]
/*
* This file is subject to the terms and conditions of the GNU General Public
* License. See the file "COPYING" in the main directory of this archive
* for more details.
*
* arch/shmedia/boot/compressed/head.S
*
* Copied from
* arch/shmedia/kernel/head.S
* which carried the copyright:
* Copyright (C) 2000, 2001 Paolo Alberelli
*
* Modification for compressed loader:
* Copyright (C) 2002 Stuart Menefy (stuart.menefy@st.com)
*/
#include <asm/cache.h>
#include <asm/cpu/mmu_context.h>
#include <asm/cpu/registers.h>
/*
* Fixed TLB entries to identity map the beginning of RAM
*/
#define MMUIR_TEXT_H 0x0000000000000003 | CONFIG_MEMORY_START
/* Enabled, Shared, ASID 0, Eff. Add. 0xA0000000 */
#define MMUIR_TEXT_L 0x000000000000009a | CONFIG_MEMORY_START
/* 512 Mb, Cacheable (Write-back), execute, Not User, Ph. Add. */
#define MMUDR_CACHED_H 0x0000000000000003 | CONFIG_MEMORY_START
/* Enabled, Shared, ASID 0, Eff. Add. 0xA0000000 */
#define MMUDR_CACHED_L 0x000000000000015a | CONFIG_MEMORY_START
/* 512 Mb, Cacheable (Write-back), read/write, Not User, Ph. Add. */
#define ICCR0_INIT_VAL ICCR0_ON | ICCR0_ICI /* ICE + ICI */
#define ICCR1_INIT_VAL ICCR1_NOLOCK /* No locking */
#if 1
#define OCCR0_INIT_VAL OCCR0_ON | OCCR0_OCI | OCCR0_WB /* OCE + OCI + WB */
#else
#define OCCR0_INIT_VAL OCCR0_OFF
#endif
#define OCCR1_INIT_VAL OCCR1_NOLOCK /* No locking */
.text
.global startup
startup:
/*
* Prevent speculative fetch on device memory due to
* uninitialized target registers.
* This must be executed before the first branch.
*/
ptabs/u r63, tr0
ptabs/u r63, tr1
ptabs/u r63, tr2
ptabs/u r63, tr3
ptabs/u r63, tr4
ptabs/u r63, tr5
ptabs/u r63, tr6
ptabs/u r63, tr7
synci
/*
* Set initial TLB entries for cached and uncached regions.
* Note: PTA/BLINK is PIC code, PTABS/BLINK isn't !
*/
/* Clear ITLBs */
pta 1f, tr1
movi ITLB_FIXED, r21
movi ITLB_LAST_VAR_UNRESTRICTED+TLB_STEP, r22
1: putcfg r21, 0, r63 /* Clear MMUIR[n].PTEH.V */
addi r21, TLB_STEP, r21
bne r21, r22, tr1
/* Clear DTLBs */
pta 1f, tr1
movi DTLB_FIXED, r21
movi DTLB_LAST_VAR_UNRESTRICTED+TLB_STEP, r22
1: putcfg r21, 0, r63 /* Clear MMUDR[n].PTEH.V */
addi r21, TLB_STEP, r21
bne r21, r22, tr1
/* Map one big (512Mb) page for ITLB */
movi ITLB_FIXED, r21
movi MMUIR_TEXT_L, r22 /* PTEL first */
putcfg r21, 1, r22 /* Set MMUIR[0].PTEL */
movi MMUIR_TEXT_H, r22 /* PTEH last */
putcfg r21, 0, r22 /* Set MMUIR[0].PTEH */
/* Map one big CACHED (512Mb) page for DTLB */
movi DTLB_FIXED, r21
movi MMUDR_CACHED_L, r22 /* PTEL first */
putcfg r21, 1, r22 /* Set MMUDR[0].PTEL */
movi MMUDR_CACHED_H, r22 /* PTEH last */
putcfg r21, 0, r22 /* Set MMUDR[0].PTEH */
/* ICache */
movi ICCR_BASE, r21
movi ICCR0_INIT_VAL, r22
movi ICCR1_INIT_VAL, r23
putcfg r21, ICCR_REG0, r22
putcfg r21, ICCR_REG1, r23
synci
/* OCache */
movi OCCR_BASE, r21
movi OCCR0_INIT_VAL, r22
movi OCCR1_INIT_VAL, r23
putcfg r21, OCCR_REG0, r22
putcfg r21, OCCR_REG1, r23
synco
/*
* Enable the MMU.
* From here-on code can be non-PIC.
*/
movi SR_HARMLESS | SR_ENABLE_MMU, r22
putcon r22, SSR
movi 1f, r22
putcon r22, SPC
synco
rte /* And now go into the hyperspace ... */
1: /* ... that's the next instruction ! */
/* Set initial stack pointer */
movi datalabel stack_start, r0
ld.l r0, 0, r15
/*
* Clear bss
*/
pt 1f, tr1
movi datalabel __bss_start, r22
movi datalabel _end, r23
1: st.l r22, 0, r63
addi r22, 4, r22
bne r22, r23, tr1
/*
* Decompress the kernel.
*/
pt decompress_kernel, tr0
blink tr0, r18
/*
* Disable the MMU.
*/
movi SR_HARMLESS, r22
putcon r22, SSR
movi 1f, r22
putcon r22, SPC
synco
rte /* And now go into the hyperspace ... */
1: /* ... that's the next instruction ! */
/* Jump into the decompressed kernel */
movi datalabel (CONFIG_MEMORY_START + 0x2000)+1, r19
ptabs r19, tr0
blink tr0, r18
/* Shouldn't return here, but just in case, loop forever */
pt 1f, tr0
1: blink tr0, r63