diff options
Diffstat (limited to 'memdisk/setup.c')
| -rw-r--r-- | memdisk/setup.c | 45 |
1 files changed, 30 insertions, 15 deletions
diff --git a/memdisk/setup.c b/memdisk/setup.c index 7af16108..013f3dfa 100644 --- a/memdisk/setup.c +++ b/memdisk/setup.c @@ -81,8 +81,9 @@ struct edd_dpt { uint16_t bytespersec; /* Bytes/sector */ uint16_t dpte_off, dpte_seg; /* DPTE pointer */ uint16_t dpikey; /* Device Path Info magic */ + uint8_t dpilen; /* Device Path Info length */ uint8_t res1; /* Reserved */ - uint8_t res2; /* Reserved */ + uint16_t res2; /* Reserved */ uint8_t bustype[4]; /* Host bus type */ uint8_t inttype[8]; /* Interface type */ uint64_t intpath; /* Interface path */ @@ -717,6 +718,17 @@ static void relocate_rm_code(uint32_t newbase) sti(); } +static uint8_t checksum_buf(const void *buf, int count) +{ + const uint8_t *p = buf; + uint8_t c; + + while (count--) + c += *p++; + + return c; +} + #define STACK_NEEDED 512 /* Number of bytes of stack */ struct real_mode_args rm_args; @@ -896,20 +908,23 @@ void setup(const struct real_mode_args *rm_args_ptr) /* Set up an EDD drive parameter table */ if (do_edd) { - pptr->edd_dpt.sectors = geometry->sectors; - /* The EDD spec has this as <= 15482880 sectors (1024x240x63); - this seems to make very little sense. Try for something saner. */ - if (geometry->c <= 1024 && geometry->h <= 255 && geometry->s <= 63) { - pptr->edd_dpt.c = geometry->c; - pptr->edd_dpt.h = geometry->h; - pptr->edd_dpt.s = geometry->s; - pptr->edd_dpt.flags |= 0x0002; /* Geometry valid */ - } - if (!(geometry->driveno & 0x80)) { - /* Floppy drive. Mark it as a removable device with - media change notification; media is present. */ - pptr->edd_dpt.flags |= 0x0014; - } + pptr->edd_dpt.sectors = geometry->sectors; + /* The EDD spec has this as <= 15482880 sectors (1024x240x63); + this seems to make very little sense. Try for something saner. */ + if (geometry->c <= 1024 && geometry->h <= 255 && geometry->s <= 63) { + pptr->edd_dpt.c = geometry->c; + pptr->edd_dpt.h = geometry->h; + pptr->edd_dpt.s = geometry->s; + pptr->edd_dpt.flags |= 0x0002; /* Geometry valid */ + } + if (!(geometry->driveno & 0x80)) { + /* Floppy drive. Mark it as a removable device with + media change notification; media is present. */ + pptr->edd_dpt.flags |= 0x0014; + } + + pptr->edd_dpt.devpath[0] = pptr->diskbuf; + pptr->edd_dpt.chksum = -checksum_buf(&pptr->edd_dpt.dpikey, 73-30); } /* The size is given by hptr->total_size plus the size of the E820 |