Hello Liu, That works -- but I think the addition of the next_symbol_value() function is over-kill, and it introduces an unnecessary (although presumably impossible) FATAL error. Why not simplify it to do something like this:

if ((string = pc->read_vmcoreinfo("CONFIG_ARM_LPAE"))) { machdep->flags |= PAE; free(string); } else if ((sp = next_symbol("swapper_pg_dir")) && (sp->value - symbol_value("swapper_pg_dir")) == 0x5000)) machdep->flags |= PAE; Thanks, Dave ----- Original Message ----- > Thanks to Dave's suggest, I impove the way to identify > LPAE enabled kernel for arm platform, for compatibility with > some old kernel. > > If a vmcore santisfy one of the following conditions, It must > be generated by a LPAE enabled kernel. > > (1) it has CONFIG_ARM_LPAE=y vmcore_info > (2) swapper_pg_dir and its next symbol value differ by 0x5000 > > Signed-off-by: Liu Hua <sdu.liu(a)huawei.com&gt; > --- > arm.c | 11 ++++++++++- > symbols.c | 10 ++++++++++ > 2 files changed, 20 insertions(+), 1 deletion(-) > > diff --git a/arm.c b/arm.c > index cb7d841..76ba699 100644 > --- a/arm.c > +++ b/arm.c > @@ -190,6 +190,8 @@ void > arm_init(int when) > { > ulong vaddr; > + char *string; > + ulong difference; > > #if defined(__i386__) || defined(__x86_64__) > if (ACTIVE()) > @@ -229,8 +231,15 @@ arm_init(int when) > * LPAE requires an additional page for the PGD, > * so PG_DIR_SIZE = 0x5000 for LPAE > */ > - if ((symbol_value("_text") - symbol_value("swapper_pg_dir")) == 0x5000) > + if ((string = pc->read_vmcoreinfo("CONFIG_ARM_LPAE"))) { > machdep->flags |= PAE; > + free(string); > + } else { > + difference = next_symbol_value("swapper_pg_dir", NULL) > + - symbol_value("swapper_pg_dir"); > + if (difference == 0x5000) > + machdep->flags |= PAE; > + } > machdep->kvbase = symbol_value("_stext") & ~KVBASE_MASK; > machdep->identity_map_base = machdep->kvbase; > machdep->is_kvaddr = arm_is_kvaddr; > diff --git a/symbols.c b/symbols.c > index a0f256e..b294cd2 100644 > --- a/symbols.c > +++ b/symbols.c > @@ -4936,6 +4936,16 @@ try_get_symbol_data(char *symbol, long size, void > *local) > return FALSE; > } > > +ulong > +next_symbol_value(char *symbol, struct syment *psb) > +{ > + struct syment *sp; > + > + if (!(sp = next_symbol(symbol, psb))) > + error(FATAL, "cannot resolve \"%s\"\n", symbol); > + return(sp->value); > +} > + > /* > * Return the value of a given symbol. > */ > -- > 1.9.0 > > .