[PATCH 40/47] Update CRISv32 kernel/head.S

Jesper Nilsson
2007-12-06T12:54:53Z

- Shorten include paths for machine specific header files.
- Add magic for booting NAND flash.
- Change CONFIG_ETRAXFS_SIM to CONFIG_ETRAX_VCS_SIM.
- Use assembler macros for initializing hardware (clocks)
- Add stubs for SMP slave CPUs.
- Search for cramfs or jffs2 if no romfs found.
- Initialize l2cache.

Signed-off-by: Jesper Nilsson <jesper.nilsson@axis.com>
---
arch/cris/arch-v32/kernel/head.S | 202 +++++++++++++++++++++-----------------
1 files changed, 114 insertions(+), 88 deletions(-)

diff --git a/arch/cris/arch-v32/kernel/head.S b/arch/cris/arch-v32/kernel/head.S
index 20bd80a..96ad000 100644
--- a/arch/cris/arch-v32/kernel/head.S
+++ b/arch/cris/arch-v32/kernel/head.S
@@ -4,22 +4,25 @@
* Copyright (C) 2003, Axis Communications AB
*/

-
#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>
+#include <hwregs/reg_rdwr.h>
+#include <asm/arch/memmap.h>
+#include <hwregs/intr_vect.h>
+#include <hwregs/asm/mmu_defs_asm.h>
+#include <hwregs/asm/reg_map_asm.h>
+#include <asm/arch/mach/startup.inc>

#define CRAMFS_MAGIC 0x28cd3d45
+#define JHEAD_MAGIC 0x1FF528A6
+#define JHEAD_SIZE 8
#define RAM_INIT_MAGIC 0x56902387
#define COMMAND_LINE_MAGIC 0x87109563
+#define NAND_BOOT_MAGIC 0x9a9db001

;; NOTE: R8 and R9 carry information from the decompressor (if the
;; kernel was compressed). They must not be used in the code below
@@ -30,12 +33,11 @@
.global romfs_start
.global romfs_length
.global romfs_in_flash
+ .global nand_boot
.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
+#ifdef CONFIG_ETRAX_VCS_SIM
.section ".boot", "ax"
ba tstart
nop
@@ -51,33 +53,13 @@ tstart:
;;
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]
+ START_CLOCKS
+
+ SETUP_WAIT_STATES
+
+#ifdef CONFIG_SMP
+secondary_cpu_entry: /* Entry point for secondary CPUs */
+ di
#endif

;; Setup and enable the MMU. Use same configuration for both the data
@@ -85,7 +67,7 @@ tstart:
;;
;; 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
+#ifndef CONFIG_ETRAX_VCS_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
@@ -93,7 +75,7 @@ tstart:
;; 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_c, 4) \
| REG_FIELD(mmu, rw_mm_kbase_hi, base_b, 0xb) \
| REG_FIELD(mmu, rw_mm_kbase_hi, base_a, 0xa), $r0
#endif
@@ -104,7 +86,7 @@ tstart:

;; Enable certain page protections and setup linear mapping
;; for f,e,c,b,4,0.
-#ifndef CONFIG_ETRAXFS_SIM
+#ifndef CONFIG_ETRAX_VCS_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) \
@@ -183,17 +165,11 @@ tstart:
nop
nop
nop
- move $s10, $r0
+ move $s12, $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
@@ -203,9 +179,16 @@ slave_wait:
jsr smp_callin
nop
master_cpu:
+ /* Set up entry point for secondary CPUs. The boot ROM has set up
+ * EBP at start of internal memory. The CPU will get there
+ * later when we issue an IPI to them... */
+ move.d MEM_INTMEM_START + IPI_INTR_VECT * 4, $r0
+ move.d secondary_cpu_entry, $r1
+ move.d $r1, [$r0]
#endif
-#ifndef CONFIG_ETRAXFS_SIM
- ;; Check if starting from DRAM or flash.
+#ifndef CONFIG_ETRAX_VCS_SIM
+ ; Check if starting from DRAM (network->RAM boot or unpacked
+ ; compressed kernel), or directly from flash.
lapcq ., $r0
and.d 0x7fffffff, $r0 ; Mask off the non-cache bit.
cmp.d 0x10000, $r0 ; Arbitrary, something above this code.
@@ -232,12 +215,13 @@ _inflash:
beq _dram_initialized
nop

-#include "../lib/dram_init.S"
+#include "../mach/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.
+ ;; Leave the cramfs file system (piggybacked after the kernel) in flash.
moveq 0, $r0 ; Source.
move.d text_start, $r1 ; Destination.
move.d __vmlinux_end, $r2
@@ -249,7 +233,7 @@ _dram_initialized:
blo 1b
nop

- ;; Keep CRAMFS in flash.
+ ;; Check for cramfs.
moveq 0, $r0
move.d romfs_length, $r1
move.d $r0, [$r1]
@@ -258,6 +242,7 @@ _dram_initialized:
bne 1f
nop

+ ;; Set length and start of cramfs, set romfs_in_flash flag
addoq +4, $r4, $acr
move.d [$acr], $r0
move.d romfs_length, $r1
@@ -273,35 +258,32 @@ _dram_initialized:
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]
+ ;; Check if booting from NAND flash; if so, set appropriate flags
+ ;; and move on.
+ cmp.d NAND_BOOT_MAGIC, $r12
+ bne move_cramfs ; not nand, jump
moveq 1, $r0
- move.d romfs_in_flash, $r1
+ move.d nand_boot, $r1 ; tell axisflashmap we're booting from NAND
move.d $r0, [$r1]
- jump _start_it
+ moveq 0, $r0 ; tell axisflashmap romfs is not in
+ move.d romfs_in_flash, $r1 ; (directly accessed) flash
+ move.d $r0, [$r1]
+ jump _start_it ; continue with boot
nop

move_cramfs:
- ;; Move the cramfs after BSS.
+ ;; kernel is in DRAM.
+ ;; Must figure out if there is a piggybacked rootfs image or not.
+ ;; Set romfs_length to 0 => no rootfs image available by default.
moveq 0, $r0
move.d romfs_length, $r1
move.d $r0, [$r1]

-#ifndef CONFIG_ETRAXFS_SIM
+#ifndef CONFIG_ETRAX_VCS_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
+ ;; the cramfs image could still be in the flash immediately
+ ;; following the compressed kernel image. The loader passes the address
+ ;; of the byte succeeding the last compressed byte in the flash in
;; register R9 when starting the kernel.
cmp.d 0x0ffffff8, $r9
bhs _no_romfs_in_flash ; R9 points outside the flash area.
@@ -310,11 +292,13 @@ move_cramfs:
ba _no_romfs_in_flash
nop
#endif
+ ;; cramfs rootfs might to be in flash. Check for it.
move.d [$r9], $r0 ; cramfs_super.magic
cmp.d CRAMFS_MAGIC, $r0
bne _no_romfs_in_flash
nop

+ ;; found cramfs in flash. set address and size, and romfs_in_flash flag.
addoq +4, $r9, $acr
move.d [$acr], $r0
move.d romfs_length, $r1
@@ -330,27 +314,43 @@ move_cramfs:
nop

_no_romfs_in_flash:
- ;; Look for cramfs.
+ ;; No romfs in flash, so look for cramfs, or jffs2 with jhead,
+ ;; after kernel in RAM, as is the case with network->RAM boot.
+ ;; For cramfs, partition starts with magic and length.
+ ;; For jffs2, a jhead is prepended which contains with magic and length.
+ ;; The jhead is not part of the jffs2 partition however.
#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
+ cmp.d CRAMFS_MAGIC, $r1 ; cramfs magic?
+ beq 2f ; yes, jump
+ nop
+ cmp.d JHEAD_MAGIC, $r1 ; jffs2 (jhead) magic?
+ bne 4f ; no, skip copy
+ nop
+ addq 4, $r0 ; location of jffs2 size
+ move.d [$r0+], $r2 ; fetch jffs2 size -> r2
+ ; r0 now points to start of jffs2
+ ba 3f
nop
+2:
+ addoq +4, $r0, $acr ; location of cramfs size
+ move.d [$acr], $r2 ; fetch cramfs size -> r2
+ ; r0 still points to start of cramfs
+3:
+ ;; Now, move the root fs to after kernel's BSS

- addoq +4, $r0, $acr
- move.d [$acr], $r2
- move.d _end, $r1
+ move.d _end, $r1 ; start of cramfs -> r1
move.d romfs_start, $r3
- move.d $r1, [$r3]
+ move.d $r1, [$r3] ; store at romfs_start (for axisflashmap)
move.d romfs_length, $r3
- move.d $r2, [$r3]
+ move.d $r2, [$r3] ; store size at romfs_length

-#ifndef CONFIG_ETRAXFS_SIM
- add.d $r2, $r0
+#ifndef CONFIG_ETRAX_VCS_SIM
+ add.d $r2, $r0 ; copy from end and downwards
add.d $r2, $r1

lsrq 1, $r2 ; Size is in bytes, we copy words.
@@ -365,10 +365,17 @@ _no_romfs_in_flash:
nop
#endif

-2:
+4:
+ ;; BSS move done.
+ ;; Clear romfs_in_flash flag, as we now know romfs is in DRAM
+ ;; Also clear nand_boot flag; if we got here, we know we've not
+ ;; booted from NAND flash.
moveq 0, $r0
move.d romfs_in_flash, $r1
move.d $r0, [$r1]
+ moveq 0, $r0
+ move.d nand_boot, $r1
+ move.d $r0, [$r1]

jump _start_it ; Jump to cached code.
nop
@@ -384,8 +391,8 @@ _start_it:
move.d cris_command_line, $r10
or.d 0x80000000, $r11 ; Make it virtual
1:
- move.b [$r11+], $r12
- move.b $r12, [$r10+]
+ move.b [$r11+], $r1
+ move.b $r1, [$r10+]
subq 1, $r13
bne 1b
nop
@@ -401,7 +408,7 @@ no_command_line:
move.d etrax_irv, $r1 ; Set the exception base register and pointer.
move.d $r0, [$r1]

-#ifndef CONFIG_ETRAXFS_SIM
+#ifndef CONFIG_ETRAX_VCS_SIM
;; Clear the BSS region from _bss_start to _end.
move.d __bss_start, $r0
move.d _end, $r1
@@ -411,7 +418,7 @@ no_command_line:
nop
#endif

-#ifdef CONFIG_ETRAXFS_SIM
+#ifdef CONFIG_ETRAX_VCS_SIM
/* Set the watchdog timeout to something big. Will be removed when */
/* watchdog can be disabled with command line option */
move.d 0x7fffffff, $r10
@@ -423,25 +430,44 @@ no_command_line:
move.d __bss_start, $r0
movem [$r0], $r13

+#ifdef CONFIG_ETRAX_L2CACHE
+ jsr l2cache_init
+ nop
+#endif
+
jump start_kernel ; Jump to start_kernel() in init/main.c.
nop

.data
etrax_irv:
.dword 0
+
+; Variables for communication with the Axis flash map driver (axisflashmap),
+; and for setting up memory in arch/cris/kernel/setup.c .
+
+; romfs_start is set to the start of the root file system, if it exists
+; in directly accessible memory (i.e. NOR Flash when booting from Flash,
+; or RAM when booting directly from a network-downloaded RAM image)
romfs_start:
.dword 0
+
+; romfs_length is set to the size of the root file system image, if it exists
+; in directly accessible memory (see romfs_start). Otherwise it is set to 0.
romfs_length:
.dword 0
+
+; romfs_in_flash is set to 1 if the root file system resides in directly
+; accessible flash memory (i.e. NOR flash). It is set to 0 for RAM boot
+; or NAND flash boot.
romfs_in_flash:
.dword 0
-crisv32_nand_boot:
- .dword 0
-crisv32_nand_cramfs_offset:
+
+; nand_boot is set to 1 when the kernel has been booted from NAND flash
+nand_boot:
.dword 0

swapper_pg_dir = 0xc0002000

.section ".init.data", "aw"

-#include "../lib/hw_settings.S"
+#include "../mach/hw_settings.S"
--
1.5.3.6.970.gd25430