Same boot SSD: 8GByte PowerMac G5 Dual boots fine; 12GByte and 16GByte PowerMac G5 Quad cores usually hang...

[Mark Millard]

Context: a boot SSD with

FreeBSD FBSDG5S1 10.1-PRERELEASE FreeBSD 10.1-PRERELEASE #0 r271243: Mon Sep  8 06:28:03 UTC 2014     root at releng1.nyi.freebsd.org:/usr/obj/powerpc.powerpc64/usr/src/sys/GENERIC64  powerpc

moved between PowerMacs. One PowerMac kind has no boot problems. The other kind frequently ends up hung with a blank screen just before the Copyright would normally show up: the start of the FreeBSD boot messages never show up. (The fans eventually speed up.)

The working PowerMac is the Dual Processor (single core each) PCI-X based one:

FreeBSD 10.1-PRERELEASE #0 r271243: Mon Sep  8 06:28:03 UTC 2014
    root at releng1.nyi.freebsd.org:/usr/obj/powerpc.powerpc64/usr/src/sys/GENERIC64 powerpc
gcc version 4.2.1 20070831 patched [FreeBSD]
VT: running with driver "ofwfb".
cpu0: IBM PowerPC 970 revision 2.2, 2000.23 MHz
cpu0: Features dc000000<PPC32,PPC64,ALTIVEC,FPU,MMU>
cpu0: HID0 511081<NAP,DPM,NHR,TBEN,ENATTN>
real memory  = 8569122816 (8172 MB)
avail memory = 8148094976 (7770 MB)
FreeBSD/SMP: Multiprocessor System Detected: 2 CPUs
cpu0: dev=ff887e10 (BSP)
cpu1: dev=ff889150

[   277.833] (--) RADEON(0): Chipset: "ATI Radeon 9800PRO NH (AGP)" (ChipID = 0x4e48)


An example of the frequently failing-boot kind of PowerMac Quad core G5 PCI-Express context is:

FreeBSD 10.1-PRERELEASE #0 r271278: Mon Sep  8 12:40:56 PDT 2014
    root at FBSDG5S0:/usr/obj/usr/src/sys/GENERIC64 powerpc
gcc version 4.2.1 20070831 patched [FreeBSD]
VT: running with driver "ofwfb".
cpu0: IBM PowerPC 970MP revision 1.1, 2500.34 MHz
cpu0: Features dc000000<PPC32,PPC64,ALTIVEC,FPU,MMU>
cpu0: HID0 1511081<DEEPNAP,NAP,DPM,NHR,TBEN,ENATTN>
real memory  = 17152716800 (16358 MB)
avail memory = 16374759424 (15616 MB)
FreeBSD/SMP: Multiprocessor System Detected: 4 CPUs
cpu0: dev=ff89d680 (BSP)
cpu1: dev=ff89eb70
cpu2: dev=ff89f248
cpu3: dev=ff89f920

(The other example I have access to has 12 GBytes of RAM instead. Both examples behave the same.)

[  3310.669] (--) NV(0): Chipset: "GeForce 7800 GT"



Some of the differences are (working context on left of "vs.", failing on right):

PowerPC 970 rev 2.2 vs. PowerPC 970MP rev 1.1
(I.e., two single-core processors vs. two dual-core processors)
8 GBytes RAM vs. 12 or 16 GBytes RAM (and slower vs. faster RAM)
ATI Radeon 9800PRO NH (AGP) vs. GeForce 7800 GT
clock rate: 2GHz vs. 2.5 GHz
PCI-X vs. PCI-Express
gem ethernet vs. bge ethernet
Whatever the OpenFirmware and such details are for the two kinds of PowerMacs.



Merely having more than 2 GBytes RAM or 4 GBytes RAM is not enough context for there to be a boot-hang problem.





===
Mark Millard
markmi at dsl-only.net