Quoting York Sun <york....@nxp.com>:

On 04/04/2016 03:01 AM, Mario Six wrote:

Quoting York Sun <york....@nxp.com>:

On 04/01/2016 01:13 AM, Mario Six wrote:
To enable DM on MPC85xx, we need pre-relocation malloc, which is
implemented in this patch.

We also make sure that the IVORs are always 4-aligned on e500 to prevent
alignment exceptions caused by code changes in start.S.

Signed-off-by: Mario Six <mario....@gdsys.cc>
Cc: York Sun <york....@nxp.com>
Cc: Simon Glass <s...@chromium.org>
---

v2:
 - Correct IVOR alignment and remove nop hack
 - Add sanity check for length of malloc area


 arch/powerpc/cpu/mpc85xx/cpu_init_early.c |  8 --------
arch/powerpc/cpu/mpc85xx/start.S | 28 ++++++++++++++++++++++++++++
 include/ppc_asm.tmpl                      |  3 +++
 3 files changed, 31 insertions(+), 8 deletions(-)

diff --git a/arch/powerpc/cpu/mpc85xx/cpu_init_early.c
b/arch/powerpc/cpu/mpc85xx/cpu_init_early.c
index 235a635..e6e1688 100644
--- a/arch/powerpc/cpu/mpc85xx/cpu_init_early.c
+++ b/arch/powerpc/cpu/mpc85xx/cpu_init_early.c
@@ -82,7 +82,6 @@ void setup_ifc(void)
 void cpu_init_early_f(void *fdt)
 {
        u32 mas0, mas1, mas2, mas3, mas7;
-       int i;
 #ifdef CONFIG_SYS_FSL_ERRATUM_P1010_A003549
        ccsr_gur_t *gur = (void *)(CONFIG_SYS_MPC85xx_GUTS_ADDR);
 #endif
@@ -95,13 +94,6 @@ void cpu_init_early_f(void *fdt)
        /* Pointer is writable since we allocated a register for it */
        gd = (gd_t *) (CONFIG_SYS_INIT_RAM_ADDR + CONFIG_SYS_GBL_DATA_OFFSET);

-       /*
-        * Clear initial global data
-        *   we don't use memset so we can share this code with NAND_SPL
-        */
-       for (i = 0; i < sizeof(gd_t); i++)
-               ((char *)gd)[i] = 0;
-

I would appreciate a comment here to explain GD had been zeroed by ...


Sure, will add in v3.

 #ifdef CONFIG_QEMU_E500
        /*
         * CONFIG_SYS_CCSRBAR_PHYS below may use gd->fdt_blob on ePAPR systems,
diff --git a/arch/powerpc/cpu/mpc85xx/start.S
b/arch/powerpc/cpu/mpc85xx/start.S
index d867e2a..cc4cf5f 100644
--- a/arch/powerpc/cpu/mpc85xx/start.S
+++ b/arch/powerpc/cpu/mpc85xx/start.S
@@ -1152,6 +1152,34 @@ _start_cont:
        /* Setup the stack in initial RAM,could be L2-as-SRAM or L1 dcache*/
        lis     r3,(CONFIG_SYS_INIT_RAM_ADDR)@h
        ori     r3,r3,((CONFIG_SYS_INIT_SP_OFFSET-16)&~0xf)@l /* Align to 16 */
+
+#ifdef CONFIG_SYS_MALLOC_F_LEN
+
+#if CONFIG_SYS_MALLOC_F_LEN + GENERATED_GBL_DATA_SIZE >
CONFIG_SYS_INIT_RAM_SIZE
+#error "CONFIG_SYS_MALLOC_F_LEN too large to fit into initial RAM."
+#endif

I am not an expert on linking. I wonder if there can be a way to
determine the
max depth of stack. If we can, a check here would be great. If we
can't, we have
to live with it.

+
+       /* Leave 16+ byte for back chain termination and NULL return address */
+       subi    r3,r3,((CONFIG_SYS_MALLOC_F_LEN+16+15)&~0xf)
+
+       /* End of RAM */
+       lis     r4,(CONFIG_SYS_INIT_RAM_ADDR)@h
+       ori     r4,r4,(CONFIG_SYS_INIT_RAM_SIZE)@l
+
+       li      r0,0
+
+1:     subi    r4,r4,4
+       stw     r0,0(r4)
+       cmplw   r4,r3
+       bne     1b
+
+       lis     r4,(CONFIG_SYS_INIT_RAM_ADDR)@h
+       ori     r4,r4,(CONFIG_SYS_GBL_DATA_OFFSET)@l
+
+       addi    r3,r3,16        /* Pre-relocation malloc area */
+       stw     r3,GD_MALLOC_BASE(r4)
+       subi    r3,r3,16
+#endif
        li      r0,0
        stw     r0,0(r3)        /* Terminate Back Chain */
        stw     r0,+4(r3)       /* NULL return address. */

I was thinking to add .align 4 before the start of exception vectors.


I tried

diff --git a/arch/powerpc/cpu/mpc85xx/start.S
b/arch/powerpc/cpu/mpc85xx/start.S
index d867e2a..921c6f5 100644
--- a/arch/powerpc/cpu/mpc85xx/start.S
+++ b/arch/powerpc/cpu/mpc85xx/start.S
@@ -1177,6 +1177,7 @@ _start_cont:
        /* NOTREACHED - board_init_f() does not return */

  #ifndef MINIMAL_SPL
+       .align 4
        .globl  _start_of_vectors
  _start_of_vectors:

without the aligns in ppc_asm.tmpl, and that crashes the board, I'm afraid.


Actually it is correct to add the alignment in ppc_asm.tmpl. It wasn't correct
before but we were lucky to run this far.

York

OK, I'll keep the aligns in ppc_asm.tmpl.

Also, I noticed a mistake on my part: The RAM has to be zeroed in start.S,
regardless of whether CONFIG_SYS_MALLOC_F_LEN is defined or not, since I
removed the zeroing from cpu_init_early.c. I'll fix that in v3, too.

Best regards,

Mario

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