target/linux/brcm-2.4/image/lzma-loader/src/head.S

   1 /* Copyright 2005 Oleg I. Vdovikin (oleg@cs.msu.su)     */
   2 /* cache manipulation adapted from Broadcom code        */
   3 /* idea taken from original bunzip2 decompressor code   */
   4 /* Copyright 2004 Manuel Novoa III (mjn3@codepoet.org)  */
   5 /* Licensed under the linux kernel's version of the GPL.*/
   6
   7 #include <asm/asm.h>
   8 #include <asm/regdef.h>
   9
  10 #define KSEG0           0x80000000
  11
  12 #define C0_CONFIG       $16
  13 #define C0_TAGLO        $28
  14 #define C0_TAGHI        $29
  15
  16 #define CONF1_DA_SHIFT  7                       /* D$ associativity */
  17 #define CONF1_DA_MASK   0x00000380
  18 #define CONF1_DA_BASE   1
  19 #define CONF1_DL_SHIFT  10                      /* D$ line size */
  20 #define CONF1_DL_MASK   0x00001c00
  21 #define CONF1_DL_BASE   2
  22 #define CONF1_DS_SHIFT  13                      /* D$ sets/way */
  23 #define CONF1_DS_MASK   0x0000e000
  24 #define CONF1_DS_BASE   64
  25 #define CONF1_IA_SHIFT  16                      /* I$ associativity */
  26 #define CONF1_IA_MASK   0x00070000
  27 #define CONF1_IA_BASE   1
  28 #define CONF1_IL_SHIFT  19                      /* I$ line size */
  29 #define CONF1_IL_MASK   0x00380000
  30 #define CONF1_IL_BASE   2
  31 #define CONF1_IS_SHIFT  22                      /* Instruction cache sets/way */
  32 #define CONF1_IS_MASK   0x01c00000
  33 #define CONF1_IS_BASE   64
  34
  35 #define Index_Invalidate_I      0x00
  36 #define Index_Writeback_Inv_D   0x01
  37
  38         .text
  39         LEAF(startup)
  40         .set noreorder
  41         addi    sp, -48
  42         sw      a0, 16(sp)
  43         sw      a1, 20(sp)
  44         sw      a2, 24(sp)
  45         sw      a3, 28(sp)
  46
  47         /* Copy decompressor code to the right place */
  48         li      t2, BZ_TEXT_START
  49         add     a0, t2, 0
  50         la      a1, code_start
  51         la      a2, code_stop
  52 $L1:
  53         lw      t0, 0(a1)
  54         sw      t0, 0(a0)
  55         add     a1, 4
  56         add     a0, 4
  57         blt     a1, a2, $L1
  58         nop
  59
  60         /* At this point we need to invalidate dcache and */
  61         /* icache before jumping to new code */
  62
  63 1:      /* Get cache sizes */
  64         .set    mips32
  65         mfc0    s0,C0_CONFIG,1
  66         .set    mips0
  67
  68         li      s1,CONF1_DL_MASK
  69         and     s1,s0
  70         beq     s1,zero,nodc
  71         nop
  72
  73         srl     s1,CONF1_DL_SHIFT
  74         li      t0,CONF1_DL_BASE
  75         sll     s1,t0,s1                /* s1 has D$ cache line size */
  76
  77         li      s2,CONF1_DA_MASK
  78         and     s2,s0
  79         srl     s2,CONF1_DA_SHIFT
  80         addiu   s2,CONF1_DA_BASE        /* s2 now has D$ associativity */
  81
  82         li      t0,CONF1_DS_MASK
  83         and     t0,s0
  84         srl     t0,CONF1_DS_SHIFT
  85         li      s3,CONF1_DS_BASE
  86         sll     s3,s3,t0                /* s3 has D$ sets per way */
  87
  88         multu   s2,s3                   /* sets/way * associativity */
  89         mflo    t0                      /* total cache lines */
  90
  91         multu   s1,t0                   /* D$ linesize * lines */
  92         mflo    s2                      /* s2 is now D$ size in bytes */
  93
  94         /* Initilize the D$: */
  95         mtc0    zero,C0_TAGLO
  96         mtc0    zero,C0_TAGHI
  97
  98         li      t0,KSEG0                /* Just an address for the first $ line */
  99         addu    t1,t0,s2                /*  + size of cache == end */
 100
 101         .set    mips3
 102 1:      cache   Index_Writeback_Inv_D,0(t0)
 103         .set    mips0
 104         bne     t0,t1,1b
 105         addu    t0,s1
 106
 107 nodc:
 108         /* Now we get to do it all again for the I$ */
 109
 110         move    s3,zero                 /* just in case there is no icache */
 111         move    s4,zero
 112
 113         li      t0,CONF1_IL_MASK
 114         and     t0,s0
 115         beq     t0,zero,noic
 116         nop
 117
 118         srl     t0,CONF1_IL_SHIFT
 119         li      s3,CONF1_IL_BASE
 120         sll     s3,t0                   /* s3 has I$ cache line size */
 121
 122         li      t0,CONF1_IA_MASK
 123         and     t0,s0
 124         srl     t0,CONF1_IA_SHIFT
 125         addiu   s4,t0,CONF1_IA_BASE     /* s4 now has I$ associativity */
 126
 127         li      t0,CONF1_IS_MASK
 128         and     t0,s0
 129         srl     t0,CONF1_IS_SHIFT
 130         li      s5,CONF1_IS_BASE
 131         sll     s5,t0                   /* s5 has I$ sets per way */
 132
 133         multu   s4,s5                   /* sets/way * associativity */
 134         mflo    t0                      /* s4 is now total cache lines */
 135
 136         multu   s3,t0                   /* I$ linesize * lines */
 137         mflo    s4                      /* s4 is cache size in bytes */
 138
 139         /* Initilize the I$: */
 140         mtc0    zero,C0_TAGLO
 141         mtc0    zero,C0_TAGHI
 142
 143         li      t0,KSEG0                /* Just an address for the first $ line */
 144         addu    t1,t0,s4                /*  + size of cache == end */
 145
 146         .set    mips3
 147 1:      cache   Index_Invalidate_I,0(t0)
 148         .set    mips0
 149         bne     t0,t1,1b
 150         addu    t0,s3
 151
 152 noic:
 153         move    a0,s3                   /* icache line size */
 154         move    a1,s4                   /* icache size */
 155         move    a2,s1                   /* dcache line size */
 156         jal     t2
 157         move    a3,s2                   /* dcache size */
 158
 159         .set reorder
 160         END(startup)