[PATCH 1/1] i386: Add support for AMD new-style boot mechanism.

[Danny Milosavljevic <danny.milo@datacom.wien>]

This introduces a new generic-loader setting "csbaseaddr" that
allows you to set the segment base address of CS.

Signed-off-by: Danny Milosavljevic <danny.milo@datacom.wien>
---
 hw/core/generic-loader.c         |  5 ++++-
 include/hw/core/cpu.h            |  1 +
 include/hw/core/generic-loader.h |  1 +
 target/i386/cpu.c                | 11 +++++++++++
 4 files changed, 17 insertions(+), 1 deletion(-)

diff --git a/hw/core/generic-loader.c b/hw/core/generic-loader.c
index 2b2a7b5e9a..a151dcdd89 100644
--- a/hw/core/generic-loader.c
+++ b/hw/core/generic-loader.c
@@ -53,6 +53,8 @@ static void generic_loader_reset(void *opaque)
         cpu_reset(s->cpu);
         if (cc) {
             cc->set_pc(s->cpu, s->addr);
+            if (cc->set_csbase)
+                cc->set_csbase(s->cpu, s->csbaseaddr);
         }
     }
 
@@ -103,7 +105,7 @@ static void generic_loader_realize(DeviceState *dev, Error **errp)
         if (s->cpu_num != CPU_NONE) {
             s->set_pc = true;
         }
-    } else if (s->addr) {
+    } else if (s->addr || s->csbaseaddr) {
         /* User is setting the PC */
         if (s->data || s->data_len || s->data_be) {
             error_setg(errp, "data can not be specified when setting a "
@@ -180,6 +182,7 @@ static void generic_loader_unrealize(DeviceState *dev)
 }
 
 static Property generic_loader_props[] = {
+    DEFINE_PROP_UINT64("csbaseaddr", GenericLoaderState, csbaseaddr, 0xffff0000),
     DEFINE_PROP_UINT64("addr", GenericLoaderState, addr, 0),
     DEFINE_PROP_UINT64("data", GenericLoaderState, data, 0),
     DEFINE_PROP_UINT8("data-len", GenericLoaderState, data_len, 0),
diff --git a/include/hw/core/cpu.h b/include/hw/core/cpu.h
index c005d3dc2d..9998b6b986 100644
--- a/include/hw/core/cpu.h
+++ b/include/hw/core/cpu.h
@@ -161,6 +161,7 @@ struct CPUClass {
     void (*get_memory_mapping)(CPUState *cpu, MemoryMappingList *list,
                                Error **errp);
     void (*set_pc)(CPUState *cpu, vaddr value);
+    void (*set_csbase)(CPUState *cpu, vaddr value);
     hwaddr (*get_phys_page_debug)(CPUState *cpu, vaddr addr);
     hwaddr (*get_phys_page_attrs_debug)(CPUState *cpu, vaddr addr,
                                         MemTxAttrs *attrs);
diff --git a/include/hw/core/generic-loader.h b/include/hw/core/generic-loader.h
index 19d87b39c8..b407d8e8e9 100644
--- a/include/hw/core/generic-loader.h
+++ b/include/hw/core/generic-loader.h
@@ -29,6 +29,7 @@ struct GenericLoaderState {
     /* <public> */
     CPUState *cpu;
 
+    uint64_t csbaseaddr;
     uint64_t addr;
     uint64_t data;
     uint8_t data_len;
diff --git a/target/i386/cpu.c b/target/i386/cpu.c
index 6a53446e6a..7cb4634e18 100644
--- a/target/i386/cpu.c
+++ b/target/i386/cpu.c
@@ -7171,6 +7171,16 @@ static void x86_cpu_set_pc(CPUState *cs, vaddr value)
     cpu->env.eip = value;
 }
 
+static void x86_cpu_set_csbase(CPUState *cs, vaddr value)
+{
+    X86CPU *cpu = X86_CPU(cs);
+    CPUX86State *env = &cpu->env;
+
+    cpu_x86_load_seg_cache(env, R_CS, 0xf000, value, 0xffff,
+                            DESC_P_MASK | DESC_S_MASK | DESC_CS_MASK |
+                            DESC_R_MASK | DESC_A_MASK);
+}
+
 int x86_cpu_pending_interrupt(CPUState *cs, int interrupt_request)
 {
     X86CPU *cpu = X86_CPU(cs);
@@ -7412,6 +7422,7 @@ static void x86_cpu_common_class_init(ObjectClass *oc, void *data)
 
     cc->dump_state = x86_cpu_dump_state;
     cc->set_pc = x86_cpu_set_pc;
+    cc->set_csbase = x86_cpu_set_csbase;
     cc->gdb_read_register = x86_cpu_gdb_read_register;
     cc->gdb_write_register = x86_cpu_gdb_write_register;
     cc->get_arch_id = x86_cpu_get_arch_id;
-- 
2.29.2