BALATON Zoltan <bala...@eik.bme.hu> writes: > Hello, > > On Mon, 18 Feb 2019, Markus Armbruster wrote: >> Machine "sam460ex" maps its flash memory at address 0xFFF00000. When >> no image is supplied, its size is 1MiB (0x100000). Else, it's the >> size of the image rounded up to the next multiple of 64KiB. >> >> The rounding is actually useless: pflash_cfi01_realize() fails with >> "failed to read the initial flash content" unless it's a no-op. >> >> I have no idea what happens when the pflash's size exceeds 1MiB. >> Useful outcomes seem unlikely. >> >> I guess memory at the end of the address space remains unmapped when >> it's smaller than 1MiB. Again, useful outcomes seem unlikely. > > I'm not sure where this was coming from but it predates my changes so > no idea either. > >> Set the flash memory size to 1MiB regardless of image size, to match >> the physical hardware. > > Actually the real hardware seems to have a 512 kB flash chip: > https://eu.mouser.com/datasheet/2/268/atmel_AT49BV040B-1180330.pdf
Fascinating. <http://www.sam4x0.com/sam460ex.html> confirms. > so while you're at it you could change FLASH_SIZE to match that. Leads to more questions, below. >> Cc: BALATON Zoltan <bala...@eik.bme.hu> >> Signed-off-by: Markus Armbruster <arm...@redhat.com> >> --- >> hw/ppc/sam460ex.c | 23 ++++++++--------------- >> 1 file changed, 8 insertions(+), 15 deletions(-) >> >> diff --git a/hw/ppc/sam460ex.c b/hw/ppc/sam460ex.c >> index 75250d49e4..ca8d7ab9c6 100644 >> --- a/hw/ppc/sam460ex.c >> +++ b/hw/ppc/sam460ex.c >> @@ -92,31 +92,24 @@ struct boot_info { >> static int sam460ex_load_uboot(void) >> { >> DriveInfo *dinfo; >> - BlockBackend *blk = NULL; >> - hwaddr base = FLASH_BASE | ((hwaddr)FLASH_BASE_H << 32); >> - long bios_size = FLASH_SIZE; >> - int fl_sectors; >> >> dinfo = drive_get(IF_PFLASH, 0, 0); >> - if (dinfo) { >> - blk = blk_by_legacy_dinfo(dinfo); >> - bios_size = blk_getlength(blk); > > After this maybe the > #include "sysemu/block-backend.h" > can also be dropped from the includes? I'll try. >> - } >> - fl_sectors = (bios_size + 65535) >> 16; >> - >> - if (!pflash_cfi01_register(base, NULL, "sam460ex.flash", bios_size, >> - blk, 64 * KiB, fl_sectors, >> + if (!pflash_cfi01_register(FLASH_BASE | ((hwaddr)FLASH_BASE_H << 32), >> + NULL, "sam460ex.flash", FLASH_SIZE, >> + dinfo ? blk_by_legacy_dinfo(dinfo) : NULL, >> + 65536, FLASH_SIZE / 65536, > > Could you keep 64 * KiB instead of 65536 here to match other places? Sure (editing accident). > Regards, > BALATON Zoltan > >> 1, 0x89, 0x18, 0x0000, 0x0, 1)) { >> error_report("Error registering flash memory"); >> /* XXX: return an error instead? */ >> exit(1); >> } >> >> - if (!blk) { >> + if (!dinfo) { >> /*error_report("No flash image given with the 'pflash' parameter," >> " using default u-boot image");*/ >> - base = UBOOT_LOAD_BASE | ((hwaddr)FLASH_BASE_H << 32); >> - rom_add_file_fixed(UBOOT_FILENAME, base, -1); >> + rom_add_file_fixed(UBOOT_FILENAME, >> + UBOOT_LOAD_BASE | ((hwaddr)FLASH_BASE_H << 32), >> + -1); >> } >> >> return 0; Let's have a look at the resulting function: static int sam460ex_load_uboot(void) { DriveInfo *dinfo; dinfo = drive_get(IF_PFLASH, 0, 0); if (!pflash_cfi01_register(FLASH_BASE | ((hwaddr)FLASH_BASE_H << 32), "sam460ex.flash", FLASH_SIZE, dinfo ? blk_by_legacy_dinfo(dinfo) : NULL, 65536, 1, 0x89, 0x18, 0x0000, 0x0, 1)) { error_report("Error registering flash memory"); /* XXX: return an error instead? */ exit(1); } if (!dinfo) { /*error_report("No flash image given with the 'pflash' parameter," " using default u-boot image");*/ rom_add_file_fixed(UBOOT_FILENAME, UBOOT_LOAD_BASE | ((hwaddr)FLASH_BASE_H << 32), -1); } return 0; } This first creates 1MiB of flash memory mapped at the end of the 32-bit address space (0xFFF00000..0xFFFFFFFF). If_PFLASH unit 0 is defined, the flash memory is initialized from that block backend. Else, it's initialized to zero. And then 512KiB of ROM gets mapped on top of its second half (0xFFF80000..0xFFFFFFFF), initialized from u-boot-sam460-20100605.bin (which we build). This doesn't smell right. I propose to do the following: if IF_PFLASH unit 0 is defined, create 512KiB of flash memory mapped at the end of the 32-bit address space, else, create 512KiB of ROM there. Okay?
