[U-Boot-Users] [PATCH 1/8] ppc4xx: Consolidate 405 and 440 NAND booting code in start.S

Stefan Roese
2008-06-02T19:02:29Z

This patch consolidates the 405 and 440 parts of the NAND booting code
selected via CONFIG_NAND_SPL. Now common code is used to initialize the
SDRAM by calling initdram() and to "copy/relocate" to SDRAM/OCM/etc.
Only *after* running from this location, nand_boot() is called.

Please note that the initsdram() call is now moved from nand_boot.c
to start.S. I experienced problems with some boards like Kilauea
(405EX), which don't have internal SRAM (OCM) and relocation needs to
be done to SDRAM before the NAND controller can get accessed. When
initdram() is called later on in nand_boot(), this can lead to problems
with variables in the bss sections like nand_ecc_pos[].

Signed-off-by: Stefan Roese <sr@denx.de>
---
cpu/ppc4xx/start.S | 206 ++++++++++++++++++++--------------------------------
1 files changed, 80 insertions(+), 126 deletions(-)

diff --git a/cpu/ppc4xx/start.S b/cpu/ppc4xx/start.S
index a5d9ec9..25ee369 100644
--- a/cpu/ppc4xx/start.S
+++ b/cpu/ppc4xx/start.S
@@ -187,6 +187,10 @@
* at CFG_SDRAM_BASE and another 128MB cacheable instruction region covering
* NOR flash at CFG_FLASH_BASE. Disable all cacheable data regions.
*/
+#if !defined(CFG_FLASH_BASE)
+/* If not already defined, set it to the "last" 128MByte region */
+# define CFG_FLASH_BASE 0xf8000000
+#endif
#if !defined(CFG_ICACHE_SACR_VALUE)
# define CFG_ICACHE_SACR_VALUE \
(PPC_128MB_SACR_VALUE(CFG_SDRAM_BASE + ( 0 << 20)) | \
@@ -486,97 +490,6 @@ rsttlb: tlbwe r0,r1,0x0000 /* Invalidate all entries (V=0)*/
/* Continue from 'normal' start */
/*----------------------------------------------------------------*/
2:
-
-#if defined(CONFIG_NAND_SPL)
-#if defined(CONFIG_440EPX) || defined(CONFIG_440GRX) || \
- defined(CONFIG_460EX) || defined(CONFIG_460GT)
- /*
- * Enable internal SRAM (only on 440EPx/GRx, 440EP/GR have no OCM)
- */
- lis r2,0x7fff
- ori r2,r2,0xffff
- mfdcr r1,isram0_dpc
- and r1,r1,r2 /* Disable parity check */
- mtdcr isram0_dpc,r1
- mfdcr r1,isram0_pmeg
- and r1,r1,r2 /* Disable pwr mgmt */
- mtdcr isram0_pmeg,r1
-#if defined(CONFIG_460EX) || defined(CONFIG_460GT)
- lis r1,0x4000 /* BAS = 8000_0000 */
- ori r1,r1,0x4580 /* 16k */
- mtdcr isram0_sb0cr,r1
-#endif
-#endif
-#if defined(CONFIG_440EP)
- /*
- * On 440EP with no internal SRAM, we setup SDRAM very early
- * and copy the NAND_SPL to SDRAM and jump to it
- */
- /* Clear Dcache to use as RAM */
- addis r3,r0,CFG_INIT_RAM_ADDR at h
- ori r3,r3,CFG_INIT_RAM_ADDR at l
- addis r4,r0,CFG_INIT_RAM_END at h
- ori r4,r4,CFG_INIT_RAM_END at l
- rlwinm. r5,r4,0,27,31
- rlwinm r5,r4,27,5,31
- beq ..d_ran3
- addi r5,r5,0x0001
-..d_ran3:
- mtctr r5
-..d_ag3:
- dcbz r0,r3
- addi r3,r3,32
- bdnz ..d_ag3
- /*----------------------------------------------------------------*/
- /* Setup the stack in internal SRAM */
- /*----------------------------------------------------------------*/
- lis r1,CFG_INIT_RAM_ADDR at h
- ori r1,r1,CFG_INIT_SP_OFFSET at l
- li r0,0
- stwu r0,-4(r1)
- stwu r0,-4(r1) /* Terminate call chain */
-
- stwu r1,-8(r1) /* Save back chain and move SP */
- lis r0,RESET_VECTOR at h /* Address of reset vector */
- ori r0,r0, RESET_VECTOR@l
- stwu r1,-8(r1) /* Save back chain and move SP */
- stw r0,+12(r1) /* Save return addr (underflow vect) */
- sync
- bl early_sdram_init
- sync
-#endif /* CONFIG_440EP */
-
- /*
- * Copy SPL from cache into internal SRAM
- */
- li r4,(CFG_NAND_BOOT_SPL_SIZE >> 2) - 1
- mtctr r4
- lis r2,CFG_NAND_BOOT_SPL_SRC at h
- ori r2,r2,CFG_NAND_BOOT_SPL_SRC at l
- lis r3,CFG_NAND_BOOT_SPL_DST at h
- ori r3,r3,CFG_NAND_BOOT_SPL_DST at l
-spl_loop:
- lwzu r4,4(r2)
- stwu r4,4(r3)
- bdnz spl_loop
-
- /*
- * Jump to code in RAM
- */
- bl 00f
-00: mflr r10
- lis r3,(CFG_NAND_BOOT_SPL_SRC - CFG_NAND_BOOT_SPL_DST)@h
- ori r3,r3,(CFG_NAND_BOOT_SPL_SRC - CFG_NAND_BOOT_SPL_DST)@l
- sub r10,r10,r3
- addi r10,r10,28
- mtlr r10
- blr
-
-start_ram:
- sync
- isync
-#endif /* CONFIG_NAND_SPL */
-
bl 3f
b _start

@@ -831,7 +744,7 @@ _start:
stw r0,+12(r1) /* Save return addr (underflow vect) */

#ifdef CONFIG_NAND_SPL
- bl nand_boot /* will not return */
+ bl nand_boot_common /* will not return */
#else
GET_GOT

@@ -992,12 +905,13 @@ _start:
ori r4, r4, CFG_DCACHE_SACR_VALUE at l
mtdccr r4

-#if !(defined(CFG_EBC_PB0AP) && defined(CFG_EBC_PB0CR)) || defined(CONFIG_405EX)
+#if !(defined(CFG_EBC_PB0AP) && defined(CFG_EBC_PB0CR))
/*----------------------------------------------------------------------- */
/* Tune the speed and size for flash CS0 */
/*----------------------------------------------------------------------- */
bl ext_bus_cntlr_init
#endif
+
#if !(defined(CFG_INIT_DCACHE_CS) || defined(CFG_TEMP_STACK_OCM))
/*
* For boards that don't have OCM and can't use the data cache
@@ -1085,38 +999,6 @@ _start:
#endif /* CONFIG_405EZ */
#endif

-#ifdef CONFIG_NAND_SPL
- /*
- * Copy SPL from cache into internal SRAM
- */
- li r4,(CFG_NAND_BOOT_SPL_SIZE >> 2) - 1
- mtctr r4
- lis r2,CFG_NAND_BOOT_SPL_SRC at h
- ori r2,r2,CFG_NAND_BOOT_SPL_SRC at l
- lis r3,CFG_NAND_BOOT_SPL_DST at h
- ori r3,r3,CFG_NAND_BOOT_SPL_DST at l
-spl_loop:
- lwzu r4,4(r2)
- stwu r4,4(r3)
- bdnz spl_loop
-
- /*
- * Jump to code in RAM
- */
- bl 00f
-00: mflr r10
- lis r3,(CFG_NAND_BOOT_SPL_SRC - CFG_NAND_BOOT_SPL_DST)@h
- ori r3,r3,(CFG_NAND_BOOT_SPL_SRC - CFG_NAND_BOOT_SPL_DST)@l
- sub r10,r10,r3
- addi r10,r10,28
- mtlr r10
- blr
-
-start_ram:
- sync
- isync
-#endif /* CONFIG_NAND_SPL */
-
/*----------------------------------------------------------------------- */
/* Setup temporary stack in DCACHE or OCM if needed for SDRAM SPD. */
/*----------------------------------------------------------------------- */
@@ -1243,7 +1125,7 @@ start_ram:
bl sdram_init

#ifdef CONFIG_NAND_SPL
- bl nand_boot /* will not return */
+ bl nand_boot_common /* will not return */
#else
GET_GOT /* initialize GOT access */

@@ -2180,3 +2062,75 @@ pll_wait:
blr
function_epilog(mftlb1)
#endif /* CONFIG_440 */
+
+#if defined(CONFIG_NAND_SPL)
+/*
+ * void nand_boot_relocate(dst, src, bytes)
+ *
+ * r3 = Destination address to copy code to (in SDRAM)
+ * r4 = Source address to copy code from
+ * r5 = size to copy in bytes
+ */
+nand_boot_relocate:
+ mr r6,r3
+ mr r7,r4
+ mflr r8
+
+ /*
+ * Copy SPL from icache into SDRAM
+ */
+ subi r3,r3,4
+ subi r4,r4,4
+ srwi r5,r5,2
+ mtctr r5
+..spl_loop:
+ lwzu r0,4(r4)
+ stwu r0,4(r3)
+ bdnz ..spl_loop
+
+ /*
+ * Calculate "corrected" link register, so that we "continue"
+ * in execution in destination range
+ */
+ sub r3,r7,r6 /* r3 = src - dst */
+ sub r8,r8,r3 /* r8 = link-reg - (src - dst) */
+ mtlr r8
+ blr
+
+nand_boot_common:
+ /*
+ * First initialize SDRAM. It has to be available *before* calling
+ * nand_boot().
+ */
+ lis r3,CFG_SDRAM_BASE at h
+ ori r3,r3,CFG_SDRAM_BASE at l
+ bl initdram
+
+ /*
+ * Now copy the 4k SPL code into SDRAM and continue execution
+ * from there.
+ */
+ lis r3,CFG_NAND_BOOT_SPL_DST at h
+ ori r3,r3,CFG_NAND_BOOT_SPL_DST at l
+ lis r4,CFG_NAND_BOOT_SPL_SRC at h
+ ori r4,r4,CFG_NAND_BOOT_SPL_SRC at l
+ lis r5,CFG_NAND_BOOT_SPL_SIZE at h
+ ori r5,r5,CFG_NAND_BOOT_SPL_SIZE at l
+ bl nand_boot_relocate
+
+ /*
+ * We're running from SDRAM now!!!
+ *
+ * It is necessary for 4xx systems to relocate from running at
+ * the original location (0xfffffxxx) to somewhere else (SDRAM
+ * preferably). This is because CS0 needs to be reconfigured for
+ * NAND access. And we can't reconfigure this CS when currently
+ * "running" from it.
+ */
+
+ /*
+ * Finally call nand_boot() to load main NAND U-Boot image from
+ * NAND and jump to it.
+ */
+ bl nand_boot /* will not return */
+#endif /* CONFIG_NAND_SPL */
--
1.5.5.3