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

[Gleb Natapov]

Use PIO to get configuration info between qemu process and guest BIOS.

Signed-off-by: Gleb Natapov <address@hidden>
---

 hw/pc.c |   51 +++++++++++++++++++++++++++++++++++++++++++++++++++
 1 files changed, 51 insertions(+), 0 deletions(-)

diff --git a/hw/pc.c b/hw/pc.c
index 213ead8..ccbe4b3 100644
--- a/hw/pc.c
+++ b/hw/pc.c
@@ -44,6 +44,7 @@
 
 /* Leave a chunk of memory at the top of RAM for the BIOS ACPI tables.  */
 #define ACPI_DATA_SIZE       0x10000
+#define BIOS_CFG_IOPORT 0x1234
 
 #define MAX_IDE_BUS 2
 
@@ -53,6 +54,24 @@ static PITState *pit;
 static IOAPICState *ioapic;
 static PCIDevice *i440fx_state;
 
+typedef struct _BIOSCfgEntry {
+    uint16_t len;
+    uint8_t *data;
+} BIOSCfgEntry;
+
+typedef enum _BIOSCfgEntryNum{
+    BIOS_CFG_SIGNATURE,
+    BIOS_CFG_MAX_ENTRY
+} BIOSCfgEntryNum;
+
+typedef struct _BIOSCfgState {
+    BIOSCfgEntry entries[BIOS_CFG_MAX_ENTRY];
+    BIOSCfgEntryNum entry;
+    uint16_t cur_offset;
+} BIOSCfgState;
+
+static BIOSCfgState bios_params;
+
 static void ioport80_write(void *opaque, uint32_t addr, uint32_t data)
 {
 }
@@ -716,6 +735,33 @@ static void pc_init_ne2k_isa(NICInfo *nd, qemu_irq *pic)
     nb_ne2k++;
 }
 
+static uint32_t bios_cfg_read(void *opaque, uint32_t addr)
+{
+    BIOSCfgEntry *e = &bios_params.entries[bios_params.entry];
+
+    if (!e->data)
+        return 0;
+
+    return e->data[bios_params.cur_offset++ % e->len];
+}
+
+static void bios_cfg_write(void *opaque, uint32_t addr, uint32_t value)
+{
+    bios_params.entry = value % BIOS_CFG_MAX_ENTRY;
+    bios_params.cur_offset = 0;
+}
+
+static int bios_cfg_add_data(BIOSCfgEntryNum entry, uint8_t *data, uint16_t 
len)
+{
+    if(entry >=  BIOS_CFG_MAX_ENTRY)
+        return 0;
+
+    bios_params.entries[entry].data = data;
+    bios_params.entries[entry].len = len;
+
+    return 1;
+}
+
 /* PC hardware initialisation */
 static void pc_init1(ram_addr_t ram_size, int vga_ram_size,
                      const char *boot_device, DisplayState *ds,
@@ -871,6 +917,11 @@ static void pc_init1(ram_addr_t ram_size, int vga_ram_size,
     cpu_register_physical_memory((uint32_t)(-bios_size),
                                  bios_size, bios_offset | IO_MEM_ROM);
 
+    register_ioport_read(BIOS_CFG_IOPORT, 1, 1, bios_cfg_read, NULL);
+    register_ioport_write(BIOS_CFG_IOPORT, 1, 1, bios_cfg_write, NULL);
+
+    bios_cfg_add_data(BIOS_CFG_SIGNATURE, "QEMU", 4);
+
     bochs_bios_init();
 
     if (linux_boot)