| Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1 | /* | 
|  | 2 | * This file is subject to the terms and conditions of the GNU General Public | 
|  | 3 | * License.  See the file "COPYING" in the main directory of this archive | 
|  | 4 | * for more details. | 
|  | 5 | * | 
|  | 6 | * arch/shmedia/boot/compressed/head.S | 
|  | 7 | * | 
|  | 8 | * Copied from | 
|  | 9 | *   arch/shmedia/kernel/head.S | 
|  | 10 | * which carried the copyright: | 
|  | 11 | *   Copyright (C) 2000, 2001  Paolo Alberelli | 
|  | 12 | * | 
|  | 13 | * Modification for compressed loader: | 
|  | 14 | *   Copyright (C) 2002 Stuart Menefy (stuart.menefy@st.com) | 
|  | 15 | */ | 
|  | 16 |  | 
|  | 17 | #include <linux/linkage.h> | 
|  | 18 | #include <asm/registers.h> | 
|  | 19 | #include <asm/cache.h> | 
|  | 20 | #include <asm/mmu_context.h> | 
|  | 21 |  | 
|  | 22 | /* | 
|  | 23 | * Fixed TLB entries to identity map the beginning of RAM | 
|  | 24 | */ | 
|  | 25 | #define MMUIR_TEXT_H	0x0000000000000003 | CONFIG_MEMORY_START | 
|  | 26 | /* Enabled, Shared, ASID 0, Eff. Add. 0xA0000000 */ | 
|  | 27 | #define MMUIR_TEXT_L	0x000000000000009a | CONFIG_MEMORY_START | 
|  | 28 | /* 512 Mb, Cacheable (Write-back), execute, Not User, Ph. Add. */ | 
|  | 29 |  | 
|  | 30 | #define MMUDR_CACHED_H	0x0000000000000003 | CONFIG_MEMORY_START | 
|  | 31 | /* Enabled, Shared, ASID 0, Eff. Add. 0xA0000000 */ | 
|  | 32 | #define MMUDR_CACHED_L	0x000000000000015a | CONFIG_MEMORY_START | 
|  | 33 | /* 512 Mb, Cacheable (Write-back), read/write, Not User, Ph. Add. */ | 
|  | 34 |  | 
|  | 35 | #define	ICCR0_INIT_VAL	ICCR0_ON | ICCR0_ICI		/* ICE + ICI */ | 
|  | 36 | #define	ICCR1_INIT_VAL	ICCR1_NOLOCK			/* No locking */ | 
|  | 37 |  | 
|  | 38 | #if 1 | 
|  | 39 | #define	OCCR0_INIT_VAL	OCCR0_ON | OCCR0_OCI | OCCR0_WB	/* OCE + OCI + WB */ | 
|  | 40 | #else | 
|  | 41 | #define	OCCR0_INIT_VAL	OCCR0_OFF | 
|  | 42 | #endif | 
|  | 43 | #define	OCCR1_INIT_VAL	OCCR1_NOLOCK			/* No locking */ | 
|  | 44 |  | 
|  | 45 | .text | 
|  | 46 |  | 
|  | 47 | .global	startup | 
|  | 48 | startup: | 
|  | 49 | /* | 
|  | 50 | * Prevent speculative fetch on device memory due to | 
|  | 51 | * uninitialized target registers. | 
|  | 52 | * This must be executed before the first branch. | 
|  | 53 | */ | 
|  | 54 | ptabs/u	ZERO, tr0 | 
|  | 55 | ptabs/u	ZERO, tr1 | 
|  | 56 | ptabs/u	ZERO, tr2 | 
|  | 57 | ptabs/u	ZERO, tr3 | 
|  | 58 | ptabs/u	ZERO, tr4 | 
|  | 59 | ptabs/u	ZERO, tr5 | 
|  | 60 | ptabs/u	ZERO, tr6 | 
|  | 61 | ptabs/u	ZERO, tr7 | 
|  | 62 | synci | 
|  | 63 |  | 
|  | 64 | /* | 
|  | 65 | * Set initial TLB entries for cached and uncached regions. | 
|  | 66 | * Note: PTA/BLINK is PIC code, PTABS/BLINK isn't ! | 
|  | 67 | */ | 
|  | 68 | /* Clear ITLBs */ | 
|  | 69 | pta	1f, tr1 | 
|  | 70 | movi	ITLB_FIXED, r21 | 
|  | 71 | movi	ITLB_LAST_VAR_UNRESTRICTED+TLB_STEP, r22 | 
|  | 72 | 1:	putcfg	r21, 0, ZERO		/* Clear MMUIR[n].PTEH.V */ | 
|  | 73 | addi	r21, TLB_STEP, r21 | 
|  | 74 | bne	r21, r22, tr1 | 
|  | 75 |  | 
|  | 76 | /* Clear DTLBs */ | 
|  | 77 | pta	1f, tr1 | 
|  | 78 | movi	DTLB_FIXED, r21 | 
|  | 79 | movi	DTLB_LAST_VAR_UNRESTRICTED+TLB_STEP, r22 | 
|  | 80 | 1:	putcfg	r21, 0, ZERO		/* Clear MMUDR[n].PTEH.V */ | 
|  | 81 | addi	r21, TLB_STEP, r21 | 
|  | 82 | bne	r21, r22, tr1 | 
|  | 83 |  | 
|  | 84 | /* Map one big (512Mb) page for ITLB */ | 
|  | 85 | movi	ITLB_FIXED, r21 | 
|  | 86 | movi	MMUIR_TEXT_L, r22	/* PTEL first */ | 
|  | 87 | putcfg	r21, 1, r22		/* Set MMUIR[0].PTEL */ | 
|  | 88 | movi	MMUIR_TEXT_H, r22	/* PTEH last */ | 
|  | 89 | putcfg	r21, 0, r22		/* Set MMUIR[0].PTEH */ | 
|  | 90 |  | 
|  | 91 | /* Map one big CACHED (512Mb) page for DTLB */ | 
|  | 92 | movi	DTLB_FIXED, r21 | 
|  | 93 | movi	MMUDR_CACHED_L, r22	/* PTEL first */ | 
|  | 94 | putcfg	r21, 1, r22		/* Set MMUDR[0].PTEL */ | 
|  | 95 | movi	MMUDR_CACHED_H, r22	/* PTEH last */ | 
|  | 96 | putcfg	r21, 0, r22		/* Set MMUDR[0].PTEH */ | 
|  | 97 |  | 
|  | 98 | /* ICache */ | 
|  | 99 | movi	ICCR_BASE, r21 | 
|  | 100 | movi	ICCR0_INIT_VAL, r22 | 
|  | 101 | movi	ICCR1_INIT_VAL, r23 | 
|  | 102 | putcfg	r21, ICCR_REG0, r22 | 
|  | 103 | putcfg	r21, ICCR_REG1, r23 | 
|  | 104 | synci | 
|  | 105 |  | 
|  | 106 | /* OCache */ | 
|  | 107 | movi	OCCR_BASE, r21 | 
|  | 108 | movi	OCCR0_INIT_VAL, r22 | 
|  | 109 | movi	OCCR1_INIT_VAL, r23 | 
|  | 110 | putcfg	r21, OCCR_REG0, r22 | 
|  | 111 | putcfg	r21, OCCR_REG1, r23 | 
|  | 112 | synco | 
|  | 113 |  | 
|  | 114 | /* | 
|  | 115 | * Enable the MMU. | 
|  | 116 | * From here-on code can be non-PIC. | 
|  | 117 | */ | 
|  | 118 | movi	SR_HARMLESS | SR_ENABLE_MMU, r22 | 
|  | 119 | putcon	r22, SSR | 
|  | 120 | movi	1f, r22 | 
|  | 121 | putcon	r22, SPC | 
|  | 122 | synco | 
|  | 123 | rte				/* And now go into the hyperspace ... */ | 
|  | 124 | 1:					/* ... that's the next instruction ! */ | 
|  | 125 |  | 
|  | 126 | /* Set initial stack pointer */ | 
|  | 127 | movi	datalabel stack_start, r0 | 
|  | 128 | ld.l	r0, 0, r15 | 
|  | 129 |  | 
|  | 130 | /* | 
|  | 131 | * Clear bss | 
|  | 132 | */ | 
|  | 133 | pt	1f, tr1 | 
|  | 134 | movi	datalabel __bss_start, r22 | 
|  | 135 | movi	datalabel _end, r23 | 
|  | 136 | 1:	st.l	r22, 0, ZERO | 
|  | 137 | addi	r22, 4, r22 | 
|  | 138 | bne	r22, r23, tr1 | 
|  | 139 |  | 
|  | 140 | /* | 
|  | 141 | * Decompress the kernel. | 
|  | 142 | */ | 
|  | 143 | pt	decompress_kernel, tr0 | 
|  | 144 | blink	tr0, r18 | 
|  | 145 |  | 
|  | 146 | /* | 
|  | 147 | * Disable the MMU. | 
|  | 148 | */ | 
|  | 149 | movi	SR_HARMLESS, r22 | 
|  | 150 | putcon	r22, SSR | 
|  | 151 | movi	1f, r22 | 
|  | 152 | putcon	r22, SPC | 
|  | 153 | synco | 
|  | 154 | rte				/* And now go into the hyperspace ... */ | 
|  | 155 | 1:					/* ... that's the next instruction ! */ | 
|  | 156 |  | 
|  | 157 | /* Jump into the decompressed kernel */ | 
|  | 158 | movi	datalabel (CONFIG_MEMORY_START + 0x2000)+1, r19 | 
|  | 159 | ptabs	r19, tr0 | 
|  | 160 | blink	tr0, r18 | 
|  | 161 |  | 
|  | 162 | /* Shouldn't return here, but just in case, loop forever */ | 
|  | 163 | pt	1f, tr0 | 
|  | 164 | 1:	blink	tr0, ZERO |