Hi,
I noticed some strange behavior when using the ELDK4 gcc for compiling U-Boot for a (new) 405 target based on the current PMC405 board.
The code needs to read-modify-write a memory mapped FPGA internal register. But the FPGA access does not appear in the object and therefore it is never done.
Here are some code snippets:
1) my 'fifo' BSP command:
int do_fifo(cmd_tbl_t *cmdtp, int flag, int argc, char *argv[]) { struct pmc405v2_fpga_s *fpga = (struct pmc405v2_fpga_s *)FPGA_BA; int i; int n = 0; u32 ctrl, data, f; char str[] = "\|/-"; int abort = 0; int count = 0; int count2 = 0;
switch(argc) { case 2: /* completely read out fifo 'n' */ if (!strcmp(argv[1],"read")) { printf(" # fifo level data\n"); printf("__________________________________\n");
for (i=0; i<FIFO_COUNT; i++) { dump_fifo(fpga, i, &n); } } else if (!strcmp(argv[1],"wait")) { got_fifoirq = 0;
irq_install_handler (FPGA_IRQ, (interrupt_handler_t *)fpga_interrupt, (void*)fpga);
printf(" # fifo level data\n"); printf("__________________________________\n");
fpga->ctrl |= CTRL_FIFO_IE; for (i=0; i<FIFO_COUNT; i++) { /* enable interrupts from all fifos */ printf("DEBUG1: %p:%08x\n", &(fpga->fifo[i].ctrl), fpga->fifo[i].ctrl); --> These RMW-ops do not appear in the object and is never done! --> fpga->fifo[i].ctrl |= 0x8000; printf("DEBUG2: %p:%08x\n", &(fpga->fifo[i].ctrl), fpga->fifo[i].ctrl); }
while (1) { /* wait loop */ while(!got_fifoirq) { ...
2) Here are the used structs for the fpga variable: struct pmc405v2_fifo_s { volatile u32 data; volatile u32 ctrl; };
/* fifo ctrl register */ #define FIFO_OVERFLOW 0x00000400 #define FIFO_EMPTY 0x00000200 #define FIFO_FULL 0x00000100 #define FIFO_IE 0x00008000 #define FIFO_LEVEL_MASK 0x000000ff
#define FIFO_COUNT 4
struct pmc405v2_fpga_s { volatile u32 ctrl; volatile u32 status; volatile u32 test1; volatile u32 test2; u32 pad1[0x60 / sizeof(u32) - 4]; volatile u32 hostctrl; /* 0x0060 */ u32 pad2[0x20 / sizeof(u32) - 1]; struct pmc405v2_fifo_s fifo[FIFO_COUNT]; /* 0x0080..0x009f */ };
3) Here are some lines from the objectdump. I do not find anything from the RMW-op to the FPGA register (fpga->fifo[i].ctrl |= 0x8000;).
/data/home/matthias/projects/pmc405/V2_u-boot.git/board/esd/pmc405v2/cmd_pmc405v2.c:556 dd8: 48 00 00 01 bl dd8 <do_fifo+0x178> dd8: R_PPC_PLTREL24 printf /data/home/matthias/projects/pmc405/V2_u-boot.git/board/esd/pmc405v2/cmd_pmc405v2.c:558 ddc: 3d 20 ef 00 lis r9,-4352 de0: 80 09 00 00 lwz r0,0(r9) de4: 3b 40 00 00 li r26,0 de8: 60 00 02 00 ori r0,r0,512 dec: 90 09 00 00 stw r0,0(r9) df0: 7f 7f db 78 mr r31,r27 /data/home/matthias/projects/pmc405/V2_u-boot.git/board/esd/pmc405v2/cmd_pmc405v2.c:561 for (i=0; i<FIFO_COUNT; i++) { /* enable interrupts from all fifos */ printf("DEBUG1: %p:%08x\n", df4: 83 9b 00 00 lwz r28,0(r27) df8: 80 7e 80 cc lwz r3,-32564(r30) dfc: 7f e4 fb 78 mr r4,r31 e00: 7f 85 e3 78 mr r5,r28 e04: 48 00 00 01 bl e04 <do_fifo+0x1a4> e04: R_PPC_PLTREL24 printf /data/home/matthias/projects/pmc405/V2_u-boot.git/board/esd/pmc405v2/cmd_pmc405v2.c:564 &(fpga->fifo[i].ctrl), fpga->fifo[i].ctrl); fpga->fifo[i].ctrl |= 0x8000; printf("DEBUG2: %p:%08x\n", e08: 80 7e 80 d0 lwz r3,-32560(r30) e0c: 7f e4 fb 78 mr r4,r31 e10: 7f 85 e3 78 mr r5,r28 e14: 48 00 00 01 bl e14 <do_fifo+0x1b4> e14: R_PPC_PLTREL24 printf /data/home/matthias/projects/pmc405/V2_u-boot.git/board/esd/pmc405v2/cmd_pmc405v2.c:559 e18: 2f 9a 00 03 cmpwi cr7,r26,3 e1c: 3b ff 00 08 addi r31,r31,8 e20: 3b 7b 00 08 addi r27,r27,8 e24: 3b 5a 00 01 addi r26,r26,1 e28: 40 9e ff cc bne+ cr7,df4 <do_fifo+0x194> e2c: 3b e0 00 00 li r31,0 e30: 48 00 00 6c b e9c <do_fifo+0x23c> /data/home/matthias/projects/pmc405/V2_u-boot.git/board/esd/pmc405v2/cmd_pmc405v2.c:571 &(fpga->fifo[i].ctrl), fpga->fifo[i].ctrl); }
while (1) { /* wait loop */ while(!got_fifoirq) { count++; e34: 3b ff 00 01 addi r31,r31,1 /data/home/matthias/projects/pmc405/V2_u-boot.git/board/esd/pmc405v2/cmd_pmc405v2.c:572
4) This is how the compiler is called for the code file: ppc_4xx-gcc -g -Os -fPIC -ffixed-r14 -meabi -fno-strict-aliasing -D__KERNEL__ -DTEXT_BASE=0xFFF80000 -I/data/home/matthias/projects/pmc405/V2_u-boot.git/include -fno-builtin -ffreestanding -nostdinc -isystem /opt/eldk_400/usr/bin/../lib/gcc/powerpc-linux/4.0.0/include -pipe -DCONFIG_PPC -D__powerpc__ -DCONFIG_4xx -ffixed-r2 -ffixed-r29 -mstring -Wa,-m405 -mcpu=405 -msoft-float -Wall -Wstrict-prototypes -c -o cmd_pmc405v2.o cmd_pmc405v2.c
Any idea about what I am doing wrong?
BTW: Using -O0 instead of -Os makes everything fine - at least for the code above.
Matthias