[U-Boot] [PATCH] mpc8[5/6]xx: Ensure POST word does not get reset

From: John Schmoller jschmoller@xes-inc.com
The POST word is stored in a spare register in the PIC on MPC8[5/6]xx processors. When interrupt_init() is called, this register gets reset which resulted in all POST_RAM POSTs not being ran due to the corrupted POST word. To resolve this, store off POST word before the PIC is reset, and restore it after the PIC has been initialized.
Signed-off-by: John Schmoller jschmoller@xes-inc.com Signed-off-by: Peter Tyser ptyser@xes-inc.com --- This is a bugfix, so it'd be nice if it made it into the upcoming release if possible.
arch/powerpc/cpu/mpc85xx/interrupts.c | 16 ++++++++++++++++ arch/powerpc/cpu/mpc86xx/interrupts.c | 16 ++++++++++++++++ 2 files changed, 32 insertions(+), 0 deletions(-)
diff --git a/arch/powerpc/cpu/mpc85xx/interrupts.c b/arch/powerpc/cpu/mpc85xx/interrupts.c index a62b031..7ab7113 100644 --- a/arch/powerpc/cpu/mpc85xx/interrupts.c +++ b/arch/powerpc/cpu/mpc85xx/interrupts.c @@ -32,11 +32,23 @@ #include <command.h> #include <asm/processor.h> #include <asm/io.h> +#ifdef CONFIG_POST +#include <post.h> +#endif
int interrupt_init_cpu(unsigned int *decrementer_count) { ccsr_pic_t __iomem *pic = (void *)CONFIG_SYS_MPC8xxx_PIC_ADDR;
+#ifdef CONFIG_POST + /* + * The POST word is stored in the PIC's TFRR register which gets + * cleared when the PIC is reset. Save it off so we can restore it + * later. + */ + ulong post_word = post_word_load(); +#endif + out_be32(&pic->gcr, MPC85xx_PICGCR_RST); while (in_be32(&pic->gcr) & MPC85xx_PICGCR_RST) ; @@ -78,6 +90,10 @@ int interrupt_init_cpu(unsigned int *decrementer_count) pic->ctpr=0; /* 40080 clear current task priority register */ #endif
+#ifdef CONFIG_POST + post_word_store(post_word); +#endif + return (0); }
diff --git a/arch/powerpc/cpu/mpc86xx/interrupts.c b/arch/powerpc/cpu/mpc86xx/interrupts.c index d8ad6d3..14821f4 100644 --- a/arch/powerpc/cpu/mpc86xx/interrupts.c +++ b/arch/powerpc/cpu/mpc86xx/interrupts.c @@ -35,12 +35,24 @@ #include <mpc86xx.h> #include <command.h> #include <asm/processor.h> +#ifdef CONFIG_POST +#include <post.h> +#endif
int interrupt_init_cpu(unsigned long *decrementer_count) { volatile immap_t *immr = (immap_t *)CONFIG_SYS_IMMR; volatile ccsr_pic_t *pic = &immr->im_pic;
+#ifdef CONFIG_POST + /* + * The POST word is stored in the PIC's TFRR register which gets + * cleared when the PIC is reset. Save it off so we can restore it + * later. + */ + ulong post_word = post_word_load(); +#endif + pic->gcr = MPC86xx_PICGCR_RST; while (pic->gcr & MPC86xx_PICGCR_RST) ; @@ -74,6 +86,10 @@ int interrupt_init_cpu(unsigned long *decrementer_count) pic->ctpr = 0; /* 40080 clear current task priority register */ #endif
+#ifdef CONFIG_POST + post_word_store(post_word); +#endif + return 0; }

On Mar 10, 2011, at 4:09 PM, Peter Tyser wrote:
From: John Schmoller jschmoller@xes-inc.com
The POST word is stored in a spare register in the PIC on MPC8[5/6]xx processors. When interrupt_init() is called, this register gets reset which resulted in all POST_RAM POSTs not being ran due to the corrupted POST word. To resolve this, store off POST word before the PIC is reset, and restore it after the PIC has been initialized.
Signed-off-by: John Schmoller jschmoller@xes-inc.com Signed-off-by: Peter Tyser ptyser@xes-inc.com
This is a bugfix, so it'd be nice if it made it into the upcoming release if possible.
arch/powerpc/cpu/mpc85xx/interrupts.c | 16 ++++++++++++++++ arch/powerpc/cpu/mpc86xx/interrupts.c | 16 ++++++++++++++++ 2 files changed, 32 insertions(+), 0 deletions(-)
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participants (2)
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Kumar Gala
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Peter Tyser