[U-Boot-Users] [Patch 10/17 Try 2] U-Boot-V2:ARM:OMAP3: Add support for OMAP and Cortex A8

Menon, Nishanth x0nishan at ti.com
Wed Jun 4 07:06:26 CEST 2008


Sascha,
> -----Original Message-----
> From: Menon, Nishanth
> Sent: Tuesday, June 03, 2008 10:38 AM
> To: 'Laurent Desnogues'; u-boot-users at lists.sourceforge.net; dirk.behme at googlemail.com;
> philip.balister at gmail.com; Gopinath, Thara; Kamat, Nishant; Syed Mohammed, Khasim
> Subject: RE: [Patch 10/17] U-Boot-V2:ARM:OMAP3: Add support for OMAP and Cortex A8
>
> > -----Original Message-----
> > From: Laurent Desnogues [mailto:laurent.desnogues at gmail.com]
> > Sent: Tuesday, June 03, 2008 3:23 AM
> > To: Menon, Nishanth; u-boot-users at lists.sourceforge.net; Laurent Desnogues;
> > dirk.behme at googlemail.com; philip.balister at gmail.com; Gopinath, Thara; Kamat, Nishant; Syed
> > Subject: Re: [Patch 10/17] U-Boot-V2:ARM:OMAP3: Add support for OMAP and Cortex A8
> >
> > On Tue, Jun 3, 2008 at 10:12 AM, Sascha Hauer <s.hauer at pengutronix.de> wrote:
> > > Is this really ARMCORTEX specific or arm v7 specific?
> >
> > This is not Cortex A8 specific, it's v7-A (and hopefully will be the same
> > in upcoming ARM architectures).
> Probably ARM arch definitions need to be cleaned up a bit more? Granularity is restricted today to
> ARM CPU and not architecture..
>
> >
> > > Anyway, this looks
> > > like the start of another ifdef mess, we should create some generic hook
> > > here.
> >
> > You could perhaps mimic the way the Linux kernel handles cache stuff
> > for the various ARM architectures.
> Probably not the extent.. but yes to a lesser extent might be helpful. Common code will still exist,
> probably CP15 stuff can move out?

Keeping the current code, but resyncing based on MALLOC changes. Need clean up of ARM proc specific changes pretty soon I guess. ARMV4, V6, V7 support to be independent of common code.

Signed-off-by: Nishanth Menon<x0nishan at ti.com>

---
 arch/arm/Kconfig         |   23 +++++++++++++++++++-
 arch/arm/Makefile        |    6 +++++
 arch/arm/cpu/Makefile    |    1
 arch/arm/cpu/start-arm.S |   54 +++++++++++++++++++++++++++++++++++++++++++++++
 4 files changed, 83 insertions(+), 1 deletion(-)

Index: u-boot.v2/arch/arm/Kconfig
===================================================================
--- u-boot.v2.orig/arch/arm/Kconfig     2008-06-03 20:27:47.000000000 -0500
+++ u-boot.v2/arch/arm/Kconfig  2008-06-03 20:45:08.000000000 -0500
@@ -47,6 +47,9 @@
 config ARM926EJS
        bool

+config ARMCORTEXA8
+       bool
+
 # i.MX1, i.MXL, i.MX27 and i.MX31 are quite similar and thus
 # handled in one arch
 config ARCH_IMX
@@ -74,6 +77,10 @@
        bool
        select ARM926EJS

+config ARCH_OMAP
+       bool
+# ARM versions used varies on based on OMAP versions
+
 choice
        prompt "Select your board"

@@ -135,6 +142,12 @@
          Say Y here if your are using Phytec's phyCORE-i.MX31 (pcm037) equipped
          with a Freescale i.MX31 Processor

+config MACH_OMAP
+       bool "Texas Instruments' OMAP based platforms"
+       select ARCH_OMAP
+       help
+         Say Y if you are using Texas Instrument's OMAP based platforms
+
 endchoice

 config IMX_CLKO
@@ -144,8 +157,9 @@
          The i.MX SoCs have a Pin which can output different reference frequencies.
          Say y here if you want to have the clko command which lets you select the
          frequency to output on this pin.
-
+
 source arch/arm/mach-netx/Kconfig
+source arch/arm/mach-omap/Kconfig

 menu "Arm specific settings         "

@@ -168,6 +182,13 @@
          If you want to start a 2.6 kernel and use an
          initrd image say y here.

+config ARMCORTEXA8_DCACHE_SKIP
+       bool "Skip DCache Invlidate"
+       depends on ARMCORTEXA8
+       default n
+       help
+         If your architecture configuration uses some other method of disabling caches, enable this
+         So that the D-Cache invalidation logic is skipped
 endmenu

 source common/Kconfig
Index: u-boot.v2/arch/arm/Makefile
===================================================================
--- u-boot.v2.orig/arch/arm/Makefile    2008-06-03 20:28:20.000000000 -0500
+++ u-boot.v2/arch/arm/Makefile 2008-06-03 20:42:53.000000000 -0500
@@ -5,6 +5,7 @@
 machine-$(CONFIG_ARCH_IMX)        := imx
 machine-$(CONFIG_ARCH_NETX)       := netx
 machine-$(CONFIG_ARCH_AT91RM9200)  := at91rm9200
+machine-$(CONFIG_ARCH_OMAP)        := omap
 board-$(CONFIG_MACH_MX1ADS)       := mx1ads
 board-$(CONFIG_MACH_ECO920)       := eco920
 board-$(CONFIG_MACH_SCB9328)      := scb9328
@@ -12,6 +13,7 @@
 board-$(CONFIG_MACH_IMX27ADS)     := imx27ads
 board-$(CONFIG_MACH_NXDB500)       := netx
 board-$(CONFIG_MACH_PCM037)       := pcm037
+board-$(CONFIG_MACH_OMAP)         := omap
 # FIXME "cpu-y" never used on ARM!
 cpu-$(CONFIG_ARM920T)              := arm920t
 cpu-$(CONFIG_ARM926EJS)            := arm926ejs
@@ -70,6 +72,10 @@
 PHONY += maketools
 maketools: include/asm-arm/.arch

+# Add architecture specific flags
+ifeq ($(CONFIG_ARMCORTEXA8),y)
+CPPFLAGS += -march=armv7a
+endif

 ifneq ($(board-y),)
 BOARD  := board/$(board-y)/
Index: u-boot.v2/arch/arm/cpu/Makefile
===================================================================
--- u-boot.v2.orig/arch/arm/cpu/Makefile        2008-06-03 20:27:44.000000000 -0500
+++ u-boot.v2/arch/arm/cpu/Makefile     2008-06-03 20:42:53.000000000 -0500
@@ -6,4 +6,5 @@
 #
 obj-$(CONFIG_ARM920T) += start-arm.o
 obj-$(CONFIG_ARM926EJS) += start-arm.o
+obj-$(CONFIG_ARMCORTEXA8) += start-arm.o
 obj-$(CONFIG_ARCH_IMX31) += start-arm.o
Index: u-boot.v2/arch/arm/cpu/start-arm.S
===================================================================
--- u-boot.v2.orig/arch/arm/cpu/start-arm.S     2008-06-03 20:42:42.000000000 -0500
+++ u-boot.v2/arch/arm/cpu/start-arm.S  2008-06-03 20:42:53.000000000 -0500
@@ -157,12 +157,66 @@
 #ifdef CONFIG_ARCH_HAS_LOWLEVEL_INIT
        bl arch_init_lowlevel
 #endif
+
+#ifdef CONFIG_ARMCORTEXA8
+       /*
+        * Invalidate v7 I/D caches
+        */
+       mov     r0, #0                 /* set up for MCR */
+       mcr     p15, 0, r0, c8, c7, 0  /* invalidate TLBs */
+       mcr     p15, 0, r0, c7, c5, 0  /* invalidate icache */
+       /* Invalidate all Dcaches */
+#ifndef CONFIG_ARMCORTEXA8_DCACHE_SKIP
+       /* If Arch specific ROM code SMI handling does not exist */
+       mrc     p15, 1, r0, c0, c0, 1   /* read clidr */
+       ands    r3, r0, #0x7000000      /* extract loc from clidr */
+       mov     r3, r3, lsr #23         /* left align loc bit field */
+       beq     finished_inval  /* if loc is 0, then no need to clean */
+       mov     r10, #0                 /* start clean at cache level 0 */
+inval_loop1:
+       add     r2, r10, r10, lsr #1    /* work out 3x current cache level */
+       mov     r1, r0, lsr r2  /* extract cache type bits from clidr */
+       and     r1, r1, #7      /* mask of the bits for current cache only */
+       cmp     r1, #2          /* see what cache we have at this level */
+       blt     skip_inval              /* skip if no cache, or just i-cache */
+       mcr     p15, 2, r10, c0, c0, 0  /* select current cache level in cssr */
+       isb                             /* isb to sych the new cssr&csidr */
+       mrc     p15, 1, r1, c0, c0, 0   /* read the new csidr */
+       and     r2, r1, #7        /* extract the length of the cache lines */
+       add     r2, r2, #4              /* add 4 (line length offset) */
+       ldr     r4, =0x3ff
+       ands    r4, r4, r1, lsr #3      /* find maximum number on the way size*/
+       clz     r5, r4          /* find bit position of way size increment */
+       ldr     r7, =0x7fff
+       ands    r7, r7, r1, lsr #13 /* extract max number of the index size */
+inval_loop2:
+       mov     r9, r4          /* create working copy of max way size */
+inval_loop3:
+       orr     r11, r10, r9, lsl r5  /* factor way and cache number into r11*/
+       orr     r11, r11, r7, lsl r2    /* factor index number into r11 */
+       mcr     p15, 0, r11, c7, c6, 2  /* invalidate by set/way */
+       subs    r9, r9, #1              /* decrement the way */
+       bge     inval_loop3
+       subs    r7, r7, #1              /* decrement the index */
+       bge     inval_loop2
+skip_inval:
+       add     r10, r10, #2            /* increment cache number */
+       cmp     r3, r10
+       bgt     inval_loop1
+finished_inval:
+       mov     r10, #0                 /* swith back to cache level 0 */
+       mcr     p15, 2, r10, c0, c0, 0  /* select current cache level in cssr */
+       isb
+#endif /* CONFIG_ARMCORTEXA8_DCACHE_SKIP */
+
+#else
        /*
         * flush v4 I/D caches
         */
        mov     r0, #0
        mcr     p15, 0, r0, c7, c7, 0   /* flush v3/v4 cache */
        mcr     p15, 0, r0, c8, c7, 0   /* flush v4 TLB */
+#endif

        /*
         * disable MMU stuff and caches





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