[Qemu-devel] [PATCH] ide: Enable byte&word access to DMA address register

[Jan Kiszka <jan.kiszka@siemens.com>]

According to the specs, also byte- and word-wise access to the busmaster
DMA address register is allowed. Patch below fixes the IDE emulation
in this regard (avoiding to touch the existing common case of 32-bit
access) and makes our guest happy.

Signed-off-by: Jan Kiszka <jan.kiszka@siemens.com>
---
 hw/ide.c |   25 +++++++++++++++++++++++++
 1 file changed, 25 insertions(+)

Index: b/hw/ide.c
===================================================================
--- a/hw/ide.c
+++ b/hw/ide.c
@@ -2838,6 +2838,29 @@ static void bmdma_writeb(void *opaque, u
     }
 }
 
+static uint32_t bmdma_addr_readb(void *opaque, uint32_t addr)
+{
+    BMDMAState *bm = opaque;
+    uint32_t val;
+    val = (bm->addr >> ((addr & 3) * 8)) & 0xff;
+#ifdef DEBUG_IDE
+    printf("%s: 0x%08x\n", __func__, val);
+#endif
+    return val;
+}
+
+static void bmdma_addr_writeb(void *opaque, uint32_t addr, uint32_t val)
+{
+    BMDMAState *bm = opaque;
+    int shift = (addr & 3) * 8;
+#ifdef DEBUG_IDE
+    printf("%s: 0x%08x\n", __func__, val);
+#endif
+    bm->addr &= ~(0xFF << shift);
+    bm->addr |= (val & 0xfc) << shift;
+    bm->cur_addr = bm->addr;
+}
+
 static uint32_t bmdma_addr_readl(void *opaque, uint32_t addr)
 {
     BMDMAState *bm = opaque;
@@ -2876,6 +2899,8 @@ static void bmdma_map(PCIDevice *pci_dev
         register_ioport_write(addr + 1, 3, 1, bmdma_writeb, bm);
         register_ioport_read(addr, 4, 1, bmdma_readb, bm);
 
+        register_ioport_write(addr + 4, 4, 1, bmdma_addr_writeb, bm);
+        register_ioport_read(addr + 4, 4, 1, bmdma_addr_readb, bm);
         register_ioport_write(addr + 4, 4, 4, bmdma_addr_writel, bm);
         register_ioport_read(addr + 4, 4, 4, bmdma_addr_readl, bm);
         addr += 8;

-- 
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Corporate Competence Center Embedded Linux