I have a problem with U-Boot on the 405EP eval. board. Everything works fine until the kernel takes control and the system hangs: ------------------------------------------------------------------------------------ U-Boot 0.2.0 (May 6 2003 - 12:04:15)
CPU: IBM PowerPC 405EP Rev. A at 266.666 MHz (PLB=133, OPB=66, EBC=66 MHz) PCI async ext clock used (sync mode not supported), internal PCI arbd 16 kB I-Cache 16 kB D-Cache Board: ### No HW ID - assuming WALNUT405 I2C: ready DRAM: 128 MB Top of RAM usable for U-Boot at: 08000000 Reserving 192k for U-Boot at: 07fd0000 Reserving 132k for malloc() at: 07faf000 Reserving 112 Bytes for Board Info at: 07faef90 Reserving 44 Bytes for Global Data at: 07faef64 Stack Pointer at: 07faef48 New Stack Pointer is: 07faef48 Now running in RAM - U-Boot at: 07fd0000 FLASH: 512 kB [board.c, 767] Calling env_relocate ... env_relocate[203] offset = 0x8050000 env_relocate[221] malloced ENV at 07faf008 In: serial Out: serial Err: serial KGDB: kgdb ready ready U-Boot relocated to 07fd0000 [board.c, 913] Calling interrupt_init ... ### main_loop entered: bootdelay=3
### main_loop: bootcmd="tftpboot 0x400000 vmlinux.PPCBoot" Hit any key to stop autoboot: 0 ENET Speed is 10 Mbps - HALF duplex connection TX_BUFF 0 @ 0x07fb0228 RX_BUFF 0 @ 0x07ff3fc0 RX_BUFF 1 @ 0x07ff45c0 RX_BUFF 2 @ 0x07ff4bc0 RX_BUFF 3 @ 0x07ff51c0 Install interrupt for vector 9 ==> 07fd49c0 Install interrupt for vector 10 ==> 07fd49c0 Install interrupt for vector 11 ==> 07fd49c0 Install interrupt for vector 12 ==> 07fd49c0 Install interrupt for vector 13 ==> 07fd49c0 Install interrupt for vector 14 ==> 07fd49c0 Install interrupt for vector 15 ==> 07fd49c0 ARP broadcast 1 Got good ARP - start TFTP TFTP from server 192.168.10.6; our IP address is 192.168.10.203 Filename 'vmlinux.PPCBoot'. Load address: 0x400000 Loading: ################################################################# ######################################### done Bytes transferred = 539758 (83c6e hex) Automatic boot of image at addr 0x00400000 ... ## Booting image at 00400000 ... Image Name: Linux-2.4.21-pre5 Created: 2003-05-06 11:42:31 UTC Image Type: PowerPC Linux Kernel Image (gzip compressed) Data Size: 539694 Bytes = 527 kB Load Address: 00000000 Entry Point: 00000000 Verifying Checksum ... OK Uncompressing Kernel Image ... OK ## Current stack ends at 0x07FAE5B8 => set upper limit to 0x00800000 ## cmdline at 0x007FFC00 ... 0x007FFC16 bd address = 0x07FAEF90 memstart = 0x00000000 memsize = 0x08000000 flashstart = 0xFFF80000 flashsize = 0x00080000 flashoffset = 0x00030000 sramstart = 0x00000000 sramsize = 0x00000000 bootflags = 0x6BBA3A55 procfreq = 266.666 MHz plb_busfreq = 133.333 MHz pci_busfreq = 33.333 MHz ethaddr = 00:50:C2:1E:AF:FE IP addr = 192.168.10.203 baudrate = 115200 bps No initrd ## Transferring control to Linux (at address 00000000) ... ------------------------------------------------------------------------------------
I found that the function memset_io, invoked by early_init, corrupts the memory region where the function identify_cpu is located. This is the disassembled produced by objdump:
c0006774 <identify_cpu>: c0006774: 3d 03 c0 12 addis r8,r3,-16366 c0006778: 39 08 e1 40 addi r8,r8,-7872 c000677c: 7c ff 42 a6 mfpvr r7 c0006780: 80 a8 00 00 lwz r5,0(r8) c0006784: 7c a5 38 38 and r5,r5,r7 c0006788: 80 c8 00 04 lwz r6,4(r8) c000678c: 7c 06 28 40 cmplw r6,r5 c0006790: 41 82 00 0c beq- c000679c <identify_cpu+0x28> c0006794: 39 08 00 20 addi r8,r8,32 c0006798: 4b ff ff e8 b c0006780 <identify_cpu+0xc> c000679c: 3c c3 c0 14 addis r6,r3,-16364 c00067a0: 38 c6 f0 bc addi r6,r6,-3908 c00067a4: 54 84 10 3a rlwinm r4,r4,2,0,29 c00067a8: 7d 03 40 50 subf r8,r3,r8 c00067ac: 7d 04 31 2e stwx r8,r4,r6 c00067b0: 4e 80 00 20 blr
This is what I see in memory before executing the memset_io:
PPC405EP>go - TARGET: target has entered debug mode PPC405EP>md 0xc0006774 8 c0006774 : 0x3d03c012 1023655954 =... c0006778 : 0x3908e140 956883264 9..@ c000677c : 0x7cff42a6 2097103526 |.B. c0006780 : 0x80a80000 -2136473600 .... c0006784 : 0x7ca53838 2091202616 |.88 c0006788 : 0x80c80004 -2134376444 .... c000678c : 0x7c062840 2080778304 |.(@ c0006790 : 0x4182000c 1099038732 A... PPC405EP>go - TARGET: target has entered debug mode
This is what I see in memory after executing the memset_io:
PPC405EP>md 0xc0006774 8 c0006774 : 0xff03ffff - 16515073 .... c0006778 : 0xff08ffff - 16187393 .... c000677c : 0xff08ffff - 16187393 .... c0006780 : 0x80a80000 -2136473600 .... c0006784 : 0x7ca53838 2091202616 |.88 c0006788 : 0x80c80004 -2134376444 .... c000678c : 0x3c060840 1007028288 <..@ c0006790 : 0x7c062840 2080778304 |.(@ PPC405EP>
Anybody have already seen something like that? Is it possible that this has to do with an erroneous cache initialization?
Many thanks in advance.
llandre