toolchain/49725: pxeboot_ia32.bin built with amd64 toolchain crashes on some i386 CPUs

[jdbaker%mylinuxisp.com@localhost]

>Number:         49725
>Category:       toolchain
>Synopsis:       pxeboot_ia32.bin built with amd64 toolchain crashes on some i386 CPUs
>Confidential:   no
>Severity:       non-critical
>Priority:       medium
>Responsible:    toolchain-manager
>State:          open
>Class:          sw-bug
>Submitter-Id:   net
>Arrival-Date:   Fri Mar 06 03:10:01 +0000 2015
>Originator:     John D. Baker
>Release:        NetBSD/amd64-7.99.5
>Organization:
>Environment:
NetBSD net4501d.technoskunk.fur 7.0_BETA NetBSD 7.0_BETA (NET4501) #7: Thu Feb 26 17:26:53 CST 2015  sysop%skuld.technoskunk.fur@localhost:/d0/build/netbsd-7/obj/i386/sys/arch/i386/compile/NET4501 i386

NetBSD neoware 7.99.5 NetBSD 7.99.5 (NEOWARE) #6: Tue Mar  3 18:59:50 CST 2015  sysop%skuld.technoskunk.fur@localhost:/d0/build/current/obj/i386/sys/arch/i386/compile/NEOWARE i386

>Description:
On some i386-class systems such as Soekris net4501 with:

$ cpuctl identify 0                 
cpu0: highest basic info 00000001
cpu0: AMD Am5x86 W/B 133/160 (486-class)
cpu0: family 0x4 model 0xf stepping 0x4 (id 0x4f4)
cpu0: features 0x1<FPU>
cpu0: Initial APIC ID 0

and NeoWare thin client with:

$ cpuctl identify 0
cpu0: highest basic info 00000001
cpu0: highest extended info 80000006
cpu0: "VIA Samuel 2"
cpu0: VIA C3 Samuel 2/Ezra (686-class), 400.04 MHz
cpu0: family 0x6 model 0x7 stepping 0x3 (id 0x673)
cpu0: features 0x803035<FPU,DE,TSC,MSR,MTRR,PGE,MMX>
cpu0: features2 0x80803035<3DNOW>
cpu0: I-cache 64KB 32B/line 4-way, D-cache 64KB 32B/line 4-way
cpu0: L2 cache 64KB 32B/line 4-way
cpu0: ITLB 128 4KB entries 8-way
cpu0: DTLB 128 4KB entries 8-way
cpu0: Initial APIC ID 0

Using "pxeboot_ia32.bin" built with the amd64 toolchain crashes and
reboots the client system immediately.

>How-To-Repeat:
Attempt to boot real i[45]86 or some 686-class systems using
pxeboot_ia32.bin from amd64 release.
>Fix:
Workaround:  Always use pxeboot_ia32.bin from i386 build in mixed
i386/amd64 diskless environment.