Messages in this thread Patch in this message | | | Date | Sat, 21 Dec 2002 11:48:41 +0100 | From | (Alexander Achenbach) | Subject | Re: [PATCH] zero-size E820 memory (kernel start-up failure) |
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Hi again.
Dave Jones wrote: > > > The patch adds code to remove empty entries before sorting regions. It > > was generated for a 2.4.20 kernel. > > Looks good to me. Care to do a similar patch for 2.5 ?
This is it, to be applied against 2.5.52. I've tested the kernel on an EPOX 4BEA-R and it boots as it should.
Cheers, Alex diff -ru linux-2.5.52/arch/i386/kernel/setup.c linux-2.5.52-nullmem/arch/i386/kernel/setup.c --- linux-2.5.52/arch/i386/kernel/setup.c Mon Dec 16 03:07:56 2002 +++ linux-2.5.52-nullmem/arch/i386/kernel/setup.c Fri Dec 20 15:48:35 2002 @@ -14,6 +14,9 @@ * Moved CPU detection code to cpu/${cpu}.c * Patrick Mochel <mochel@osdl.org>, March 2002 * + * Provisions for empty E820 memory regions (reported by certain BIOSes). + * Alex Achenbach <xela@slit.de>, December 2002. + * */ /* @@ -275,7 +278,7 @@ int chgidx, still_changing; int overlap_entries; int new_bios_entry; - int old_nr, new_nr; + int old_nr, new_nr, chg_nr; int i; /* @@ -329,20 +332,24 @@ for (i=0; i < 2*old_nr; i++) change_point[i] = &change_point_list[i]; - /* record all known change-points (starting and ending addresses) */ + /* record all known change-points (starting and ending addresses), + omitting those that are for empty memory regions */ chgidx = 0; for (i=0; i < old_nr; i++) { - change_point[chgidx]->addr = biosmap[i].addr; - change_point[chgidx++]->pbios = &biosmap[i]; - change_point[chgidx]->addr = biosmap[i].addr + biosmap[i].size; - change_point[chgidx++]->pbios = &biosmap[i]; + if (biosmap[i].size != 0) { + change_point[chgidx]->addr = biosmap[i].addr; + change_point[chgidx++]->pbios = &biosmap[i]; + change_point[chgidx]->addr = biosmap[i].addr + biosmap[i].size; + change_point[chgidx++]->pbios = &biosmap[i]; + } } + chg_nr = chgidx; /* true number of change-points */ /* sort change-point list by memory addresses (low -> high) */ still_changing = 1; while (still_changing) { still_changing = 0; - for (i=1; i < 2*old_nr; i++) { + for (i=1; i < chg_nr; i++) { /* if <current_addr> > <last_addr>, swap */ /* or, if current=<start_addr> & last=<end_addr>, swap */ if ((change_point[i]->addr < change_point[i-1]->addr) || @@ -365,7 +372,7 @@ last_type = 0; /* start with undefined memory type */ last_addr = 0; /* start with 0 as last starting address */ /* loop through change-points, determining affect on the new bios map */ - for (chgidx=0; chgidx < 2*old_nr; chgidx++) + for (chgidx=0; chgidx < chg_nr; chgidx++) { /* keep track of all overlapping bios entries */ if (change_point[chgidx]->addr == change_point[chgidx]->pbios->addr) | |