kernel/linux/arch/arm/boot/compressed/head-xscale.S

   1 /*
   2  * linux/arch/arm/boot/compressed/head-xscale.S
   3  *
   4  * XScale specific tweaks.  This is merged into head.S by the linker.
   5  *
   6  */
   7
   8 #include <linux/config.h>
   9 #include <linux/linkage.h>
  10 #include <asm/mach-types.h>
  11
  12                 .section        ".start", "ax"
  13
  14 __XScale_start:
  15
  16                 @ Preserve r8/r7 i.e. kernel entry values
  17
  18                 @ Data cache might be active.
  19                 @ Be sure to flush kernel binary out of the cache,
  20                 @ whatever state it is, before it is turned off.
  21                 @ This is done by fetching through currently executed
  22                 @ memory to be sure we hit the same cache.
  23                 bic     r2, pc, #0x1f
  24                 add     r3, r2, #0x10000        @ 64 kb is quite enough...
  25 1:              ldr     r0, [r2], #32
  26                 teq     r2, r3
  27                 bne     1b
  28                 mcr     p15, 0, r0, c7, c10, 4  @ drain WB
  29                 mcr     p15, 0, r0, c7, c7, 0   @ flush I & D caches
  30
  31                 @ disabling MMU and caches
  32                 mrc     p15, 0, r0, c1, c0, 0   @ read control reg
  33                 bic     r0, r0, #0x05           @ clear DC, MMU
  34                 bic     r0, r0, #0x1000         @ clear Icache
  35                 mcr     p15, 0, r0, c1, c0, 0
  36
  37 #ifdef  CONFIG_ARCH_IQ80321
  38                 orr     pc, pc, #PHYS_OFFSET    @ jump to physical memory if we are not there.
  39                 nop
  40                 mov     r7, #MACH_TYPE_IQ80321
  41 #endif
  42
  43 #ifdef CONFIG_ARCH_LUBBOCK
  44                 mov     r7, #MACH_TYPE_LUBBOCK
  45 #endif
  46
  47 #ifdef CONFIG_ARCH_COTULLA_IDP
  48                 mov     r7, #MACH_TYPE_COTULLA_IDP
  49 #endif
  50
  51 #ifdef CONFIG_ARCH_IQ80310
  52                 /*
  53                  * Crank the CPU up to 733MHz
  54                  */
  55                 mov     r1, #9
  56                 mcr     p14, 0, r1, c6, c0, 0
  57
  58                 /*
  59                  * Disable ECC error notification
  60                  * At some point, we should add an ECC handler to Linux
  61                  */
  62                 mov     r1, #0x1500
  63                 mov     r0, #0x4
  64                 str     r0, [r1, #0x34]
  65
  66                 mov     r7, #MACH_TYPE_IQ80310
  67 #endif
  68
  69