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[Qemu-devel] Better floppy disk support
From: |
Mark Jonckheere |
Subject: |
[Qemu-devel] Better floppy disk support |
Date: |
Tue, 11 May 2004 16:21:33 +0200 |
User-agent: |
Mozilla/5.0 (X11; U; Linux i686; en-US; rv:0.9.9) Gecko/20020408 |
I propose some patches for better floppy disk support:
1. To make "tomsrtbt-2.0.103.ElTorito.288.img" bootable.
The first one is in fdc.c. It removes the test in fd_init(), since it
always forces the disk type to 1.44 MB, It is better to give the first
call to fd_revalidate() a chance to decide if it is a 1.44 or 2.88 drive.
2. To make my standalone chntpw-disk bootable (google for bd000607.zip).
Booting from bd000607.img gives a segmentation error. It seems that the
bootcode on this floppy (syslinux-ldlinux) does a word-length (16-bit)
INW at address 0x80 which was translated by function default_ioport_readw()
in a call to default_ioport_readb(NULL, 0x80) and read_page(NULL, 0x81).
The second function (in dma.c) needs a (dma_cont *) pointer as its first
parameter and segfaults when it tries to dereference the NULL-pointer.
To avoid this problem with word-length io-reads to two adjacent io-ports
from different or undefined devices it is best to translate it into two
readb calls each with its own opaque value. The function default_ioport_readw()
is not the most logical place for doing this, it is better to do this
upstream in the function cpu_inw().
I modified cpu_inw() and cpu_outw(), but the same problem could also
happen with cpu_inl() and cpu_outl().
3. To accept "--nics 0" as a legal argument.
Sometimes it can be usefull to install software without ethernet support.
I made a minor modification to accept 0 as a legal value for the argument
--nics. Since the default value remains 1, nothing changes for current usage.
greetings,
Mark.
diffs from cvs sources downloaded at 2004-05-10 11:41 (UTC) start here
---8<-------------------------------------------------------->8---
diff -wurb qemu/hw/fdc.c qemu-patched/hw/fdc.c
--- qemu/hw/fdc.c Sat May 8 23:01:23 2004
+++ qemu-patched/hw/fdc.c Mon May 10 18:18:35 2004
@@ -94,9 +94,9 @@
{
/* Drive */
drv->bs = bs;
- if (bs)
- drv->drive = FDRIVE_DRV_144;
- else
+// if (bs)
+// drv->drive = FDRIVE_DRV_144;
+// else
drv->drive = FDRIVE_DRV_NONE;
drv->drflags = 0;
drv->perpendicular = 0;
diff -wurb qemu/vl.c qemu-patched/vl.c
--- qemu/vl.c Thu Apr 29 00:26:05 2004
+++ qemu-patched/vl.c Tue May 11 14:49:07 2004
@@ -133,19 +133,19 @@
#endif
}
-/* default is to make two byte accesses */
uint32_t default_ioport_readw(void *opaque, uint32_t address)
{
- uint32_t data;
- data = ioport_read_table[0][address & (MAX_IOPORTS - 1)](opaque, address);
- data |= ioport_read_table[0][(address + 1) & (MAX_IOPORTS - 1)](opaque, address
+ 1) << 8;
- return data;
+#ifdef DEBUG_UNUSED_IOPORT
+ fprintf(stderr, "inw: port=0x%04x\n", address);
+#endif
+ return 0xffff;
}
void default_ioport_writew(void *opaque, uint32_t address, uint32_t data)
{
- ioport_write_table[0][address & (MAX_IOPORTS - 1)](opaque, address, data &
0xff);
- ioport_write_table[0][(address + 1) & (MAX_IOPORTS - 1)](opaque, address + 1, (data
>> 8) & 0xff);
+#ifdef DEBUG_UNUSED_IOPORT
+ fprintf(stderr, "outw: port=0x%04x data=0x%04x\n", address, data);
+#endif
}
uint32_t default_ioport_readl(void *opaque, uint32_t address)
@@ -159,7 +159,7 @@
void default_ioport_writel(void *opaque, uint32_t address, uint32_t data)
{
#ifdef DEBUG_UNUSED_IOPORT
- fprintf(stderr, "outl: port=0x%04x data=0x%02x\n", address, data);
+ fprintf(stderr, "outl: port=0x%04x data=0x%08x\n", address, data);
#endif
}
@@ -279,8 +279,18 @@
void cpu_outw(CPUState *env, int addr, int val)
{
+ IOPortWriteFunc *writefunc;
+
addr &= (MAX_IOPORTS - 1);
- ioport_write_table[1][addr](ioport_opaque[addr], addr, val);
+ writefunc = ioport_write_table[1][addr];
+ if ( writefunc != default_ioport_writew &&
+ (ioport_write_table[0][addr] == ioport_write_table[0][addr + 1]))
+ writefunc(ioport_opaque[addr], addr, val);
+ else {
+ ioport_write_table[0][addr](ioport_opaque[addr], addr, val & 0xff);
+ ioport_write_table[0][addr + 1](ioport_opaque[addr + 1],
+ addr + 1, (val >> 8 ) & 0xff);
+ }
}
void cpu_outl(CPUState *env, int addr, int val)
@@ -297,8 +307,16 @@
int cpu_inw(CPUState *env, int addr)
{
+ IOPortReadFunc *readfunc;
+
addr &= (MAX_IOPORTS - 1);
- return ioport_read_table[1][addr](ioport_opaque[addr], addr);
+ readfunc = ioport_read_table[1][addr];
+ if ( readfunc != default_ioport_readw &&
+ (ioport_read_table[0][addr] == ioport_read_table[0][addr + 1]))
+ return readfunc(ioport_opaque[addr], addr);
+ else
+ return ioport_read_table[0][addr](ioport_opaque[addr], addr) |
+ (ioport_read_table[0][addr+1](ioport_opaque[addr+1], addr+1) << 8);
}
int cpu_inl(CPUState *env, int addr)
@@ -2008,7 +2026,7 @@
break;
case 16:
nb_nics = atoi(optarg);
- if (nb_nics < 1 || nb_nics > MAX_NICS) {
+ if (nb_nics < 0 || nb_nics > MAX_NICS) {
fprintf(stderr, "qemu: invalid number of network
interfaces\n");
exit(1);
}
---8<-------------------------------------------------------->8---
- [Qemu-devel] Better floppy disk support,
Mark Jonckheere <=