@@ -279,23 +279,39 @@ bool exception_rflags_rf(void)
static char intr_alt_stack[4096];
-#ifndef __x86_64__
-void set_gdt_entry(int sel, u32 base, u32 limit, u8 access, u8 gran)
+static void __set_gdt_entry(int sel, uintptr_t base, u32 limit, u8 access,
+ u8 gran, gdt_entry_t *gdt)
{
int num = sel >> 3;
/* Setup the descriptor base address */
- gdt32[num].base_low = (base & 0xFFFF);
- gdt32[num].base_middle = (base >> 16) & 0xFF;
- gdt32[num].base_high = (base >> 24) & 0xFF;
+ gdt[num].base_low = (base & 0xFFFF);
+ gdt[num].base_middle = (base >> 16) & 0xFF;
+ gdt[num].base_high = (base >> 24) & 0xFF;
/* Setup the descriptor limits */
- gdt32[num].limit_low = (limit & 0xFFFF);
- gdt32[num].granularity = ((limit >> 16) & 0x0F);
+ gdt[num].limit_low = (limit & 0xFFFF);
+ gdt[num].granularity = ((limit >> 16) & 0x0F);
+
+ /* Penultimately, set up the granularity and access flags */
+ gdt[num].granularity |= (gran & 0xF0);
+ gdt[num].access = access;
+
+#ifdef __x86_64__
+ /* 64-bit system descriptors take up two slots */
+ if (!(access & 0x10000)) {
+ u32 *p = (u32 *)&gdt[num + 1];
- /* Finally, set up the granularity and access flags */
- gdt32[num].granularity |= (gran & 0xF0);
- gdt32[num].access = access;
+ p[0] = base >> 32;
+ p[1] = 0;
+ }
+#endif
+}
+
+#ifndef __x86_64__
+void set_gdt_entry(int sel, uintptr_t base, u32 limit, u8 access, u8 gran)
+{
+ __set_gdt_entry(sel, base, limit, access, gran, gdt32);
}
void set_gdt_task_gate(u16 sel, u16 tss_sel)
@@ -366,6 +382,11 @@ void print_current_tss_info(void)
tr, tr ? "interrupt" : "main", tss.prev, tss_intr.prev);
}
#else
+void set_gdt_entry(int sel, uintptr_t base, u32 limit, u8 access, u8 gran)
+{
+ __set_gdt_entry(sel, base, limit, access, gran, gdt64);
+}
+
void set_intr_alt_stack(int e, void *addr)
{
set_idt_entry(e, addr, 0);
@@ -208,6 +208,7 @@ void set_idt_task_gate(int vec, u16 sel);
void set_intr_task_gate(int vec, void *fn);
void setup_tss32(void);
#else
+extern gdt_entry_t gdt64[];
extern tss64_t tss;
#endif
@@ -218,7 +219,7 @@ bool exception_rflags_rf(void);
void set_idt_entry(int vec, void *addr, int dpl);
void set_idt_sel(int vec, u16 sel);
void set_idt_dpl(int vec, u16 dpl);
-void set_gdt_entry(int sel, u32 base, u32 limit, u8 access, u8 gran);
+void set_gdt_entry(int sel, uintptr_t base, u32 limit, u8 access, u8 gran);
void set_intr_alt_stack(int e, void *fn);
void print_current_tss_info(void);
handler handle_exception(u8 v, handler fn);
@@ -62,6 +62,7 @@ gdt64_desc:
.word gdt64_end - gdt64 - 1
.quad gdt64
+.globl gdt64
gdt64:
.quad 0
.quad 0x00af9b000000ffff // 64-bit code segment
The omission of a 64-bit implementation of set_gdt_entry was probably just an oversight, since the declaration is in scope. Signed-off-by: Jim Mattson <jmattson@google.com> --- lib/x86/desc.c | 41 +++++++++++++++++++++++++++++++---------- lib/x86/desc.h | 3 ++- x86/cstart64.S | 1 + 3 files changed, 34 insertions(+), 11 deletions(-)