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|
/*
* Head of the kernel - alter with care
*
* Copyright (C) 2000, 2001, 2010 Axis Communications AB
*
*/
#define ASSEMBLER_MACROS_ONLY
/* The IO_* macros use the ## token concatenation operator, so
-traditional must not be used when assembling this file. */
#include <arch/sv_addr_ag.h>
#define CRAMFS_MAGIC 0x28cd3d45
#define RAM_INIT_MAGIC 0x56902387
#define COMMAND_LINE_MAGIC 0x87109563
#define START_ETHERNET_CLOCK IO_STATE(R_NETWORK_GEN_CONFIG, enable, on) |\
IO_STATE(R_NETWORK_GEN_CONFIG, phy, mii_clk)
;; exported symbols
.globl etrax_irv
.globl romfs_start
.globl romfs_length
.globl romfs_in_flash
.globl swapper_pg_dir
.text
;; This is the entry point of the kernel. We are in supervisor mode.
;; 0x00000000 if Flash, 0x40004000 if DRAM
;; since etrax actually starts at address 2 when booting from flash, we
;; put a nop (2 bytes) here first so we dont accidentally skip the di
;;
;; NOTICE! The registers r8 and r9 are used as parameters carrying
;; information from the decompressor (if the kernel was compressed).
;; They should not be used in the code below until read.
nop
di
;; First setup the kseg_c mapping from where the kernel is linked
;; to 0x40000000 (where the actual DRAM resides) otherwise
;; we cannot do very much! See arch/cris/README.mm
;;
;; Notice that since we're potentially running at 0x00 or 0x40 right now,
;; we will get a fault as soon as we enable the MMU if we dont
;; temporarily map those segments linearily.
;;
;; Due to a bug in Etrax-100 LX version 1 we need to map the memory
;; slightly different. The bug is that you can't remap bit 31 of
;; an address. Though we can check the version register for
;; whether the bug is present, some constants would then have to
;; be variables, so we don't. The drawback is that you can "only" map
;; 1G per process with CONFIG_CRIS_LOW_MAP.
#ifdef CONFIG_CRIS_LOW_MAP
; kseg mappings, temporary map of 0xc0->0x40
move.d IO_FIELD (R_MMU_KBASE_HI, base_c, 4) \
| IO_FIELD (R_MMU_KBASE_HI, base_b, 0xb) \
| IO_FIELD (R_MMU_KBASE_HI, base_9, 9) \
| IO_FIELD (R_MMU_KBASE_HI, base_8, 8), $r0
move.d $r0, [R_MMU_KBASE_HI]
; temporary map of 0x40->0x40 and 0x60->0x40
move.d IO_FIELD (R_MMU_KBASE_LO, base_6, 4) \
| IO_FIELD (R_MMU_KBASE_LO, base_4, 4), $r0
move.d $r0, [R_MMU_KBASE_LO]
; mmu enable, segs e,c,b,a,6,5,4,0 segment mapped
move.d IO_STATE (R_MMU_CONFIG, mmu_enable, enable) \
| IO_STATE (R_MMU_CONFIG, inv_excp, enable) \
| IO_STATE (R_MMU_CONFIG, acc_excp, enable) \
| IO_STATE (R_MMU_CONFIG, we_excp, enable) \
| IO_STATE (R_MMU_CONFIG, seg_f, page) \
| IO_STATE (R_MMU_CONFIG, seg_e, seg) \
| IO_STATE (R_MMU_CONFIG, seg_d, page) \
| IO_STATE (R_MMU_CONFIG, seg_c, seg) \
| IO_STATE (R_MMU_CONFIG, seg_b, seg) \
| IO_STATE (R_MMU_CONFIG, seg_a, seg) \
| IO_STATE (R_MMU_CONFIG, seg_9, page) \
| IO_STATE (R_MMU_CONFIG, seg_8, page) \
| IO_STATE (R_MMU_CONFIG, seg_7, page) \
| IO_STATE (R_MMU_CONFIG, seg_6, seg) \
| IO_STATE (R_MMU_CONFIG, seg_5, seg) \
| IO_STATE (R_MMU_CONFIG, seg_4, seg) \
| IO_STATE (R_MMU_CONFIG, seg_3, page) \
| IO_STATE (R_MMU_CONFIG, seg_2, page) \
| IO_STATE (R_MMU_CONFIG, seg_1, page) \
| IO_STATE (R_MMU_CONFIG, seg_0, seg), $r0
move.d $r0, [R_MMU_CONFIG]
#else
; kseg mappings
move.d IO_FIELD (R_MMU_KBASE_HI, base_e, 8) \
| IO_FIELD (R_MMU_KBASE_HI, base_c, 4) \
| IO_FIELD (R_MMU_KBASE_HI, base_b, 0xb), $r0
move.d $r0, [R_MMU_KBASE_HI]
; temporary map of 0x40->0x40 and 0x00->0x00
move.d IO_FIELD (R_MMU_KBASE_LO, base_4, 4), $r0
move.d $r0, [R_MMU_KBASE_LO]
; mmu enable, segs f,e,c,b,4,0 segment mapped
move.d IO_STATE (R_MMU_CONFIG, mmu_enable, enable) \
| IO_STATE (R_MMU_CONFIG, inv_excp, enable) \
| IO_STATE (R_MMU_CONFIG, acc_excp, enable) \
| IO_STATE (R_MMU_CONFIG, we_excp, enable) \
| IO_STATE (R_MMU_CONFIG, seg_f, seg) \
| IO_STATE (R_MMU_CONFIG, seg_e, seg) \
| IO_STATE (R_MMU_CONFIG, seg_d, page) \
| IO_STATE (R_MMU_CONFIG, seg_c, seg) \
| IO_STATE (R_MMU_CONFIG, seg_b, seg) \
| IO_STATE (R_MMU_CONFIG, seg_a, page) \
| IO_STATE (R_MMU_CONFIG, seg_9, page) \
| IO_STATE (R_MMU_CONFIG, seg_8, page) \
| IO_STATE (R_MMU_CONFIG, seg_7, page) \
| IO_STATE (R_MMU_CONFIG, seg_6, page) \
| IO_STATE (R_MMU_CONFIG, seg_5, page) \
| IO_STATE (R_MMU_CONFIG, seg_4, seg) \
| IO_STATE (R_MMU_CONFIG, seg_3, page) \
| IO_STATE (R_MMU_CONFIG, seg_2, page) \
| IO_STATE (R_MMU_CONFIG, seg_1, page) \
| IO_STATE (R_MMU_CONFIG, seg_0, seg), $r0
move.d
|