Re: [Qemu-devel] [PATCH v2 1/6] Use IO port for qemu<->guest BIOS communication.

[Gleb Natapov]

On Tue, Aug 26, 2008 at 07:46:20PM +0300, Blue Swirl wrote:
> > Is the patch below what you mean? (not tested, but compiles)
> 
> Yes, but I'd still put the code from the .h file and pc.c to a new .c
> file, only the keys and function prototypes to .h.
> 
Okey, here is updated one (compiled only)

---
    Use IO port for qemu<->guest BIOS communication.
    
    Use PIO to get configuration info between qemu process and guest BIOS.
    
    Signed-off-by: Gleb Natapov <address@hidden>

diff --git a/Makefile.target b/Makefile.target
index 2464484..4d7a1ef 100644
--- a/Makefile.target
+++ b/Makefile.target
@@ -537,7 +537,7 @@ OBJS += e1000.o
 ifeq ($(TARGET_BASE_ARCH), i386)
 # Hardware support
 OBJS+= ide.o pckbd.o ps2.o vga.o $(SOUND_HW) dma.o
-OBJS+= fdc.o mc146818rtc.o serial.o i8259.o i8254.o pcspk.o pc.o
+OBJS+= fdc.o mc146818rtc.o serial.o i8259.o i8254.o pcspk.o pc.o fw_channel.o
 OBJS+= cirrus_vga.o apic.o parallel.o acpi.o piix_pci.o
 OBJS+= usb-uhci.o vmmouse.o vmport.o vmware_vga.o
 CPPFLAGS += -DHAS_AUDIO -DHAS_AUDIO_CHOICE
diff --git a/hw/fw_channel.c b/hw/fw_channel.c
new file mode 100644
index 0000000..581a83c
--- /dev/null
+++ b/hw/fw_channel.c
@@ -0,0 +1,54 @@
+#include "hw.h"
+#include <hw/fw_channel.h>
+
+int firmware_cfg_add(FWCfgState *s, uint16_t key, uint8_t *data, uint16_t len)
+{
+    int arch = !!(key & FW_CFG_ARCH_LOCAL);
+
+    key &= (~FW_CFG_ARCH_LOCAL);
+
+    if (key >= FW_CFG_MAX_ENTRY)
+        return 0;
+
+    s->entries[arch][key].data = data;
+    s->entries[arch][key].len = len;
+
+    return 1;
+}
+
+int firmware_cfg_select(FWCfgState *s, uint16_t key)
+{
+    int arch = !!(key & FW_CFG_ARCH_LOCAL);
+
+    key &= (~FW_CFG_ARCH_LOCAL);
+
+    s->cur_offset = 0;
+    if (key >= FW_CFG_MAX_ENTRY) {
+        s->cur_entry = NULL;
+        return 0;
+    }
+
+    s->cur_entry = &s->entries[arch][key];
+
+    return 1;
+}
+
+uint8_t firmware_cfg_read(FWCfgState *s)
+{
+    FWCfgEntry *e = s->cur_entry;
+
+    if (!e || !e->data || s->cur_offset >= e->len)
+        return 0;
+
+    return e->data[s->cur_offset++];
+}
+
+uint32_t firmware_io_cfg_read(void *opaque, uint32_t addr)
+{
+    return firmware_cfg_read(opaque);
+}
+
+void firmware_io_cfg_write(void *opaque, uint32_t addr, uint32_t value)
+{
+    firmware_cfg_select(opaque, (uint16_t)value);
+}
diff --git a/hw/fw_channel.h b/hw/fw_channel.h
new file mode 100644
index 0000000..841c1dd
--- /dev/null
+++ b/hw/fw_channel.h
@@ -0,0 +1,32 @@
+#ifndef FW_CHANNEL_H
+#define FW_CHANNEL_H
+
+#define FW_CFG_SIGNATURE        0x00
+#define FW_CFG_ID               0x01
+#define FW_CFG_MAX_ENTRY        0x10
+
+#define FW_CFG_ARCH_LOCAL       0x8000
+
+#ifndef __ASSEMBLY__
+
+typedef struct _FWCfgEntry {
+    uint16_t len;
+    uint8_t *data;
+} FWCfgEntry;
+
+typedef struct _FWCfgState {
+    FWCfgEntry entries[2][FW_CFG_MAX_ENTRY];
+    FWCfgEntry *cur_entry;
+    uint16_t cur_offset;
+} FWCfgState;
+
+int firmware_cfg_add(FWCfgState *s, uint16_t key, uint8_t *data, uint16_t len);
+int firmware_cfg_select(FWCfgState *s, uint16_t key);
+uint8_t firmware_cfg_read(FWCfgState *s);
+
+uint32_t firmware_io_cfg_read(void *opaque, uint32_t addr);
+void firmware_io_cfg_write(void *opaque, uint32_t addr, uint32_t value);
+
+#endif /* __ASSEMBLY__ */
+
+#endif
diff --git a/hw/pc.c b/hw/pc.c
index 213ead8..f7deab5 100644
--- a/hw/pc.c
+++ b/hw/pc.c
@@ -32,6 +32,7 @@
 #include "smbus.h"
 #include "boards.h"
 #include "console.h"
+#include "hw/fw_channel.h"
 
 /* output Bochs bios info messages */
 //#define DEBUG_BIOS
@@ -44,6 +45,7 @@
 
 /* Leave a chunk of memory at the top of RAM for the BIOS ACPI tables.  */
 #define ACPI_DATA_SIZE       0x10000
+#define BIOS_CFG_IOPORT 0x510
 
 #define MAX_IDE_BUS 2
 
@@ -53,6 +55,8 @@ static PITState *pit;
 static IOAPICState *ioapic;
 static PCIDevice *i440fx_state;
 
+static uint32_t bios_cfg_id = 1;
+
 static void ioport80_write(void *opaque, uint32_t addr, uint32_t data)
 {
 }
@@ -416,6 +420,8 @@ static void bochs_bios_write(void *opaque, uint32_t addr, 
uint32_t val)
 
 static void bochs_bios_init(void)
 {
+    FWCfgState *bios_params;
+
     register_ioport_write(0x400, 1, 2, bochs_bios_write, NULL);
     register_ioport_write(0x401, 1, 2, bochs_bios_write, NULL);
     register_ioport_write(0x402, 1, 1, bochs_bios_write, NULL);
@@ -426,6 +432,16 @@ static void bochs_bios_init(void)
     register_ioport_write(0x502, 1, 2, bochs_bios_write, NULL);
     register_ioport_write(0x500, 1, 1, bochs_bios_write, NULL);
     register_ioport_write(0x503, 1, 1, bochs_bios_write, NULL);
+
+    bios_params = qemu_mallocz(sizeof(FWCfgState));
+
+    register_ioport_read(BIOS_CFG_IOPORT, 1, 1, firmware_io_cfg_read,
+            bios_params);
+    register_ioport_write(BIOS_CFG_IOPORT, 1, 1, firmware_io_cfg_write,
+            bios_params);
+
+    firmware_cfg_add(bios_params, FW_CFG_SIGNATURE, "QEMU", 4);
+    firmware_cfg_add(bios_params, FW_CFG_ID, (uint8_t*)&bios_cfg_id, 4);
 }
 
 /* Generate an initial boot sector which sets state and jump to
--
                        Gleb.