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/*
* CRISv32 kernel startup code.
*
* Copyright (C) 2003, Axis Communications AB
*/
#include <linux/config.h>
#define ASSEMBLER_MACROS_ONLY
/*
* The macros found in mmu_defs_asm.h uses the ## concatenation operator, so
* -traditional must not be used when assembling this file.
*/
#include <asm/arch/hwregs/reg_rdwr.h>
#include <asm/arch/hwregs/asm/mmu_defs_asm.h>
#include <asm/arch/hwregs/asm/reg_map_asm.h>
#include <asm/arch/hwregs/asm/config_defs_asm.h>
#include <asm/arch/hwregs/asm/bif_core_defs_asm.h>
#define CRAMFS_MAGIC 0x28cd3d45
#define RAM_INIT_MAGIC 0x56902387
#define COMMAND_LINE_MAGIC 0x87109563
;; NOTE: R8 and R9 carry information from the decompressor (if the
;; kernel was compressed). They must not be used in the code below
;; until they are read!
;; Exported symbols.
.global etrax_irv
.global romfs_start
.global romfs_length
.global romfs_in_flash
.global swapper_pg_dir
.global crisv32_nand_boot
.global crisv32_nand_cramfs_offset
;; Dummy section to make it bootable with current VCS simulator
#ifdef CONFIG_ETRAXFS_SIM
.section ".boot", "ax"
ba tstart
nop
#endif
.text
tstart:
;; This is the entry point of the kernel. The CPU is currently in
;; supervisor mode.
;;
;; 0x00000000 if flash.
;; 0x40004000 if DRAM.
;;
di
;; Start clocks for used blocks.
move.d REG_ADDR(config, regi_config, rw_clk_ctrl), $r1
move.d [$r1], $r0
or.d REG_STATE(config, rw_clk_ctrl, cpu, yes) | \
REG_STATE(config, rw_clk_ctrl, bif, yes) | \
REG_STATE(config, rw_clk_ctrl, fix_io, yes), $r0
move.d $r0, [$r1]
;; Set up waitstates etc
move.d REG_ADDR(bif_core, regi_bif_core, rw_grp1_cfg), $r0
move.d CONFIG_ETRAX_MEM_GRP1_CONFIG, $r1
move.d $r1, [$r0]
move.d REG_ADDR(bif_core, regi_bif_core, rw_grp2_cfg), $r0
move.d CONFIG_ETRAX_MEM_GRP2_CONFIG, $r1
move.d $r1, [$r0]
move.d REG_ADDR(bif_core, regi_bif_core, rw_grp3_cfg), $r0
move.d CONFIG_ETRAX_MEM_GRP3_CONFIG, $r1
move.d $r1, [$r0]
move.d REG_ADDR(bif_core, regi_bif_core, rw_grp4_cfg), $r0
move.d CONFIG_ETRAX_MEM_GRP4_CONFIG, $r1
move.d $r1, [$r0]
#ifdef CONFIG_ETRAXFS_SIM
;; Set up minimal flash waitstates
move.d 0, $r10
move.d REG_ADDR(bif_core, regi_bif_core, rw_grp1_cfg), $r11
move.d $r10, [$r11]
#endif
;; Setup and enable the MMU. Use same configuration for both the data
;; and the instruction MMU.
;;
;; Note; 3 cycles is needed for a bank-select to take effect. Further;
;; bank 1 is the instruction MMU, bank 2 is the data MMU.
#ifndef CONFIG_ETRAXFS_SIM
move.d REG_FIELD(mmu, rw_mm_kbase_hi, base_e, 8) \
| REG_FIELD(mmu, rw_mm_kbase_hi, base_c, 4) \
| REG_FIELD(mmu, rw_mm_kbase_hi, base_b, 0xb), $r0
#else
;; Map the virtual DRAM to the RW eprom area at address 0.
;; Also map 0xa for the hook calls,
move.d REG_FIELD(mmu, rw_mm_kbase_hi, base_e, 8) \
| REG_FIELD(mmu, rw_mm_kbase_hi, base_c, 0) \
| REG_FIELD(mmu, rw_mm_kbase_hi, base_b, 0xb) \
| REG_FIELD(mmu, rw_mm_kbase_hi, base_a, 0xa), $r0
#endif
;; Temporary map of 0x40 -> 0x40 and 0x00 -> 0x00.
move.d REG_FIELD(mmu, rw_mm_kbase_lo, base_4, 4) \
| REG_FIELD(mmu, rw_mm_kbase_lo, base_0, 0), $r1
;; Enable certain page protections and setup linear mapping
;; for f,e,c,b,4,0.
#ifndef CONFIG_ETRAXFS_SIM
move.d REG_STATE(mmu, rw_mm_cfg, we, on) \
| REG_STATE(mmu, rw_mm_cfg, acc, on) \
| REG_STATE(mmu, rw_mm_cfg, ex, on) \
| REG_STATE(mmu, rw_mm_cfg, inv, on) \
| REG_STATE(mmu, rw_mm_cfg, seg_f, linear) \
| REG_STATE(mmu, rw_mm_cfg, seg_e, linear) \
| REG_STATE(mmu, rw_mm_cfg, seg_d, page) \
| REG_STATE(mmu, rw_mm_cfg, seg_c, linear) \
| REG_STATE(mmu, rw_mm_cfg, seg_b, linear) \
| REG_STATE(mmu, rw_mm_cfg, seg_a, page) \
| REG_STATE(mmu, rw_mm_cfg, seg_9, page) \
| REG_STATE(mmu, rw_mm_cfg, seg_8, page) \
| REG_STATE(mmu, rw_mm_cfg, seg_7, page) \
| REG_STATE(mmu, rw_mm_cfg, seg_6, page) \
| REG_STATE(mmu, rw_mm_cfg, seg_5, page) \
| REG_STATE(mmu, rw_mm_cfg, seg_4, linear) \
| REG_STATE(mmu, rw_mm_cfg, seg_3, page) \
| REG_STATE(mmu, rw_mm_cfg, seg_2, page) \
| REG_STATE(mmu, rw_mm_cfg, seg_1, page) \
| REG_STATE(mmu, rw_mm_cfg, seg_0, linear), $r2
#else
move.d REG_STATE(mmu, rw_mm_cfg, we, on) \
| REG_STATE(mmu, rw_mm_cfg, acc, on) \
| REG_STATE(mmu, rw_mm_cfg, ex, on) \
| REG_STATE(mmu, rw_mm_cfg, inv, on) \
| REG_STATE(mmu, rw_mm_cfg, seg_f, linear) \
| REG_STATE(mmu, rw_mm_cfg, seg_e, linear) \
| REG_STATE(mmu, rw_mm_cfg, seg_d, page) \
| REG_STATE(mmu, rw_mm_cfg, seg_c, linear) \
| REG_STATE(mmu, rw_mm_cfg, seg_b, linear) \
| REG_STATE(mmu, rw_mm_cfg, seg_a, linear) \
| REG_STATE(mmu, rw_mm_cfg, seg_9, page) \
| REG_STATE(mmu, rw_mm_cfg, seg_8, page) \
| REG_STATE(mmu, rw_mm_cfg, seg_7, page) \
| REG_STATE(mmu, rw_mm_cfg, seg_6, page) \
| REG_STATE(mmu, rw_mm_cfg, seg_5, page) \
| REG_STATE(mmu, rw_mm_cfg, seg_4, linear) \
| REG_STATE(mmu, rw_mm_cfg, seg_3, page) \
| REG_STATE(mmu, rw_mm_cfg, seg_2, page) \
| REG_STATE(mmu, rw_mm_cfg, seg_1, page) \
| REG_STATE(mmu, rw_mm_cfg, seg_0, linear), $r2
#endif
;; Update instruction MMU.
move 1, $srs
nop
nop
nop
move $r0, $s2 ; kbase_hi.
move $r1, $s1 ; kbase_lo.
move $r2, $s0 ; mm_cfg, virtual memory configuration.
;; Update data MMU.
move 2, $srs
nop
nop
nop
move $r0, $s2 ; kbase_hi.
move $r1, $s1 ; kbase_lo
move $r2, $s0 ; mm_cfg, virtual memory configuration.
;; Enable data and instruction MMU.
move 0, $srs
moveq 0xf, $r0 ; IMMU, DMMU, DCache, Icache on
nop
nop
nop
move $r0, $s0
nop
nop
nop
#ifdef CONFIG_SMP
;; Read CPU ID
move 0, $srs
nop
nop
nop
move $s10, $r0
cmpq 0, $r0
beq master_cpu
nop
slave_cpu:
; A slave waits for cpu_now_booting to be equal to CPU ID.
move.d cpu_now_booting, $r1
slave_wait:
cmp.d [$r1], $r0
bne slave_wait
nop
; Time to boot-up. Get stack location provided by master CPU.
move.d smp_init_current_idle_thread, $r1
move.d [$r1], $sp
add.d 8192, $sp
move.d ebp_start, $r0 ; Defined in linker-script.
move $r0, $ebp
jsr smp_callin
nop
master_cpu:
#endif
#ifndef CONFIG_ETRAXFS_SIM
;; Check if starting from DRAM or flash.
lapcq ., $r0
and.d 0x7fffffff, $r0 ; Mask off the non-cache bit.
cmp.d 0x10000, $r0 ; Arbitrary, something above this code.
blo _inflash0
nop
#endif
jump _inram ; Jump to cached RAM.
nop
;; Jumpgate.
_inflash0:
jump _inflash
nop
;; Put the following in a section so that storage for it can be
;; reclaimed after init is finished.
.section ".init.text", "ax"
_inflash:
;; Initialize DRAM.
cmp.d RAM_INIT_MAGIC, $r8 ; Already initialized?
beq _dram_initialized
nop
#include "../lib/dram_init.S"
_dram_initialized:
;; Copy the text and data section to DRAM. This depends on that the
;; variables used below are correctly set up by the linker script.
;; The calculated value stored in R4 is used below.
moveq 0, $r0 ; Source.
move.d text_start, $r1 ; Destination.
move.d __vmlinux_end, $r2
move.d $r2, $r4
sub.d $r1, $r4
1: move.w [$r0+], $r3
move.w $r3, [$r1+]
cmp.d $r2, $r1
blo 1b
nop
;; Keep CRAMFS in flash.
moveq 0, $r0
move.d romfs_length, $r1
move.d $r0, [$r1]
move.d [$r4], $r0 ; cramfs_super.magic
cmp.d CRAMFS_MAGIC, $r0
bne 1f
nop
addoq +4, $r4, $acr
move.d [$acr], $r0
move.d romfs_length, $r1
move.d $r0, [$r1]
add.d 0xf0000000, $r4 ; Add cached flash start in virtual memory.
move.d romfs_start, $r1
move.d $r4, [$r1]
1: moveq 1, $r0
move.d romfs_in_flash, $r1
move.d $r0, [$r1]
jump _start_it ; Jump to cached code.
nop
_inram:
;; Check if booting from NAND flash (in that case we just remember the offset
;; into the flash where cramfs should be).
move.d REG_ADDR(config, regi_config, r_bootsel), $r0
move.d [$r0], $r0
and.d REG_MASK(config, r_bootsel, boot_mode), $r0
cmp.d REG_STATE(config, r_bootsel, boot_mode, nand), $r0
bne move_cramfs
moveq 1,$r0
move.d crisv32_nand_boot, $r1
move.d $r0, [$r1]
move.d crisv32_nand_cramfs_offset, $r1
move.d $r9, [$r1]
moveq 1, $r0
move.d romfs_in_flash, $r1
move.d $r0, [$r1]
jump _start_it
nop
move_cramfs:
;; Move the cramfs after BSS.
moveq 0, $r0
move.d romfs_length, $r1
move.d $r0, [$r1]
#ifndef CONFIG_ETRAXFS_SIM
;; The kernel could have been unpacked to DRAM by the loader, but
;; the cramfs image could still be inte the flash immediately
;; following the compressed kernel image. The loaded passes the address
;; of the bute succeeding the last compressed byte in the flash in
;; register R9 when starting the kernel.
cmp.d 0x0ffffff8, $r9
bhs _no_romfs_in_flash ; R9 points outside the flash area.
nop
#else
ba _no_romfs_in_flash
nop
#endif
move.d [$r9], $r0 ; cramfs_super.magic
cmp.d CRAMFS_MAGIC, $r0
bne _no_romfs_in_flash
nop
addoq +4, $r9, $acr
move.d [$acr], $r0
move.d romfs_length, $r1
move.d $r0, [$r1]
add.d 0xf0000000, $r9 ; Add cached flash start in virtual memory.
move.d romfs_start, $r1
move.d $r9, [$r1]
moveq 1, $r0
move.d romfs_in_flash, $r1
move.d $r0, [$r1]
jump _start_it ; Jump to cached code.
nop
_no_romfs_in_flash:
;; Look for cramfs.
#ifndef CONFIG_ETRAXFS_SIM
move.d __vmlinux_end, $r0
#else
move.d __end, $r0
#endif
move.d [$r0], $r1
cmp.d CRAMFS_MAGIC, $r1
bne 2f
nop
addoq +4, $r0, $acr
move.d [$acr], $r2
move.d _end, $r1
move.d romfs_start, $r3
move.d $r1, [$r3]
move.d romfs_length, $r3
move.d $r2, [$r3]
#ifndef CONFIG_ETRAXFS_SIM
add.d $r2, $r0
add.d $r2, $r1
lsrq 1, $r2 ; Size is in bytes, we copy words.
addq 1, $r2
1:
move.w [$r0], $r3
move.w $r3, [$r1]
subq 2, $r0
subq 2, $r1
subq 1, $r2
bne 1b
nop
#endif
2:
moveq 0, $r0
move.d romfs_in_flash, $r1
move.d $r0, [$r1]
jump _start_it ; Jump to cached code.
nop
_start_it:
;; Check if kernel command line is supplied
cmp.d COMMAND_LINE_MAGIC, $r10
bne no_command_line
nop
move.d 256, $r13
move.d cris_command_line, $r10
or.d 0x80000000, $r11 ; Make it virtual
1:
move.b [$r11+], $r12
move.b $r12, [$r10+]
subq 1, $r13
bne 1b
nop
no_command_line:
;; The kernel stack contains a task structure for each task. This
;; the initial kernel stack is in the same page as the init_task,
;; but starts at the top of the page, i.e. + 8192 bytes.
move.d init_thread_union + 8192, $sp
move.d ebp_start, $r0 ; Defined in linker-script.
move $r0, $ebp
move.d etrax_irv, $r1 ; Set the exception base register and pointer.
move.d $r0, [$r1]
#ifndef CONFIG_ETRAXFS_SIM
;; Clear the BSS region from _bss_start to _end.
move.d __bss_start, $r0
move.d _end, $r1
1: clear.d [$r0+]
cmp.d $r1, $r0
blo 1b
nop
#endif
#ifdef CONFIG_ETRAXFS_SIM
/* Set the watchdog timeout to something big. Will be removed when */
/* watchdog can be disabled with command line option */
move.d 0x7fffffff, $r10
jsr CPU_WATCHDOG_TIMEOUT
nop
#endif
; Initialize registers to increase determinism
move.d __bss_start, $r0
movem [$r0], $r13
jump start_kernel ; Jump to start_kernel() in init/main.c.
nop
.data
etrax_irv:
.dword 0
romfs_start:
.dword 0
romfs_length:
.dword 0
romfs_in_flash:
.dword 0
crisv32_nand_boot:
.dword 0
crisv32_nand_cramfs_offset:
.dword 0
swapper_pg_dir = 0xc0002000
.section ".init.data", "aw"
#include "../lib/hw_settings.S"
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