A cdrom boot image could be over 64K in size, but the low level
drivers may not support very large reads. If a large cdrom image is
found, issue multiple reads so that a read request over 64K is never
issued.
Signed-off-by: Kevin O'Connor <kevin(a)koconnor.net>
---
src/cdrom.c | 17 +++++++++++++----
1 file changed, 13 insertions(+), 4 deletions(-)
diff --git a/src/cdrom.c b/src/cdrom.c
index de0e7de..92f34f4 100644
--- a/src/cdrom.c
+++ b/src/cdrom.c
@@ -212,12 +212,21 @@ cdrom_boot(struct drive_s *drive)
CDEmu.device_spec = drive->cntl_id % 2;
// And we read the image in memory
+ nbsectors = DIV_ROUND_UP(nbsectors, 4);
dop.lba = lba;
- dop.count = DIV_ROUND_UP(nbsectors, 4);
dop.buf_fl = MAKE_FLATPTR(boot_segment, 0);
- ret = scsi_process_op(&dop);
- if (ret)
- return 12;
+ while (nbsectors) {
+ int count = nbsectors;
+ if (count > 64*1024/CDROM_SECTOR_SIZE)
+ count = 64*1024/CDROM_SECTOR_SIZE;
+ dop.count = count;
+ ret = scsi_process_op(&dop);
+ if (ret)
+ return 12;
+ nbsectors -= count;
+ dop.lba += count;
+ dop.buf_fl += count*CDROM_SECTOR_SIZE;
+ }
if (media == 0) {
// No emulation requested - return success.
--
1.9.3
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The standard BIOS disk read/write request interface should never get a
request for more than 64K of data. Explicitly check for overly large
requests and reject them. This way, the low-level drivers do not need
to check for or attempt to handle very large requests.
Signed-off-by: Kevin O'Connor <kevin(a)koconnor.net>
---
src/block.c | 4 ++++
src/disk.c | 2 ++
2 files changed, 6 insertions(+)
diff --git a/src/block.c b/src/block.c
index 43af305..3f7ecb1 100644
--- a/src/block.c
+++ b/src/block.c
@@ -485,6 +485,10 @@ process_op(struct disk_op_s *op)
{
ASSERT16();
int ret, origcount = op->count;
+ if (origcount * GET_GLOBALFLAT(op->drive_gf->blksize) > 64*1024) {
+ op->count = 0;
+ return DISK_RET_EBOUNDARY;
+ }
u8 type = GET_GLOBALFLAT(op->drive_gf->type);
switch (type) {
case DTYPE_FLOPPY:
diff --git a/src/disk.c b/src/disk.c
index fe2e2c3..0e0af24 100644
--- a/src/disk.c
+++ b/src/disk.c
@@ -173,6 +173,7 @@ disk_1300(struct bregs *regs, struct drive_s *drive_gf)
struct disk_op_s dop;
dop.drive_gf = drive_gf;
dop.command = CMD_RESET;
+ dop.count = 0;
int status = send_disk_op(&dop);
disk_ret(regs, status);
}
@@ -322,6 +323,7 @@ disk_1310(struct bregs *regs, struct drive_s *drive_gf)
struct disk_op_s dop;
dop.drive_gf = drive_gf;
dop.command = CMD_ISREADY;
+ dop.count = 0;
int status = send_disk_op(&dop);
disk_ret(regs, status);
}
--
1.9.3