X-Git-Url: https://gerrit.opnfv.org/gerrit/gitweb?a=blobdiff_plain;f=qemu%2Froms%2Fopenbios%2Farch%2Famd64%2Fsegment.c;fp=qemu%2Froms%2Fopenbios%2Farch%2Famd64%2Fsegment.c;h=09763bd144c8851b1405419899d36a0c662f2831;hb=e44e3482bdb4d0ebde2d8b41830ac2cdb07948fb;hp=0000000000000000000000000000000000000000;hpb=9ca8dbcc65cfc63d6f5ef3312a33184e1d726e00;p=kvmfornfv.git

diff --git a/qemu/roms/openbios/arch/amd64/segment.c b/qemu/roms/openbios/arch/amd64/segment.c
new file mode 100644
index 000000000..09763bd14
--- /dev/null
+++ b/qemu/roms/openbios/arch/amd64/segment.c
@@ -0,0 +1,134 @@
+/* Segmentation of the AMD64 architecture.
+ *
+ * 2003-07 by SONE Takeshi
+ */
+
+#include "config.h"
+#include "kernel/kernel.h"
+#include "libopenbios/sys_info.h"
+#include "relocate.h"
+#include "segment.h"
+
+#define printf printk
+#ifdef CONFIG_DEBUG_BOOT
+#define debug printk
+#else
+#define debug(x...)
+#endif
+
+/* i386 lgdt argument */
+struct gdtarg {
+    unsigned short limit;
+    unsigned int base;
+} __attribute__((packed));
+
+/* How far the virtual address (used in C) is different from physical
+ * address. Since we start in flat mode, the initial value is zero. */
+unsigned long virt_offset = 0;
+
+/* GDT, the global descriptor table */
+struct segment_desc gdt[NUM_SEG] = {
+    /* 0x00: null segment */
+    {0, 0, 0, 0, 0, 0},
+    /* 0x08: flat code segment */
+    {0xffff, 0, 0, 0x9f, 0xcf, 0},
+    /* 0x10: flat data segment */
+    {0xffff, 0, 0, 0x93, 0xcf, 0},
+    /* 0x18: code segment for relocated execution */
+    {0xffff, 0, 0, 0x9f, 0xcf, 0},
+    /* 0x20: data segment for relocated execution */
+    {0xffff, 0, 0, 0x93, 0xcf, 0},
+};
+
+extern char _start[], _end[];
+
+void relocate(struct sys_info *info)
+{
+    int i;
+    unsigned long prog_addr;
+    unsigned long prog_size;
+    unsigned long addr, new_base;
+    unsigned long long segsize;
+    unsigned long new_offset;
+    unsigned d0, d1, d2;
+    struct gdtarg gdtarg;
+#define ALIGNMENT 16
+
+    prog_addr = virt_to_phys(&_start);
+    prog_size = virt_to_phys(&_end) - virt_to_phys(&_start);
+    debug("Current location: %#lx-%#lx\n", prog_addr, prog_addr+prog_size-1);
+
+    new_base = 0;
+    for (i = 0; i < info->n_memranges; i++) {
+	if (info->memrange[i].base >= 1ULL<<32)
+	    continue;
+	segsize = info->memrange[i].size;
+	if (info->memrange[i].base + segsize > 1ULL<<32)
+	    segsize = (1ULL<<32) - info->memrange[i].base;
+	if (segsize < prog_size+ALIGNMENT)
+	    continue;
+	addr = info->memrange[i].base + segsize - prog_size;
+	addr &= ~(ALIGNMENT-1);
+	if (addr >= prog_addr && addr < prog_addr + prog_size)
+	    continue;
+	if (prog_addr >= addr && prog_addr < addr + prog_size)
+	    continue;
+	if (addr > new_base)
+	    new_base = addr;
+    }
+    if (new_base == 0) {
+	printf("Can't find address to relocate\n");
+	return;
+    }
+
+    debug("Relocating to %#lx-%#lx... ",
+	    new_base, new_base + prog_size - 1);
+
+    /* New virtual address offset */
+    new_offset = new_base - (unsigned long) &_start;
+
+    /* Tweak the GDT */
+    gdt[RELOC_CODE].base_0 = (unsigned short) new_offset;
+    gdt[RELOC_CODE].base_16 = (unsigned char) (new_offset>>16);
+    gdt[RELOC_CODE].base_24 = (unsigned char) (new_offset>>24);
+    gdt[RELOC_DATA].base_0 = (unsigned short) new_offset;
+    gdt[RELOC_DATA].base_16 = (unsigned char) (new_offset>>16);
+    gdt[RELOC_DATA].base_24 = (unsigned char) (new_offset>>24);
+
+    /* Load new GDT and reload segments */
+    gdtarg.base = new_offset + (unsigned long) gdt;
+    gdtarg.limit = GDT_LIMIT;
+    __asm__ __volatile__ (
+	    "rep; movsb\n\t" /* copy everything */
+	    "lgdt %3\n\t"
+	    "ljmp %4, $1f\n1:\t"
+	    "movw %5, %%ds\n\t"
+	    "movw %5, %%es\n\t"
+	    "movw %5, %%fs\n\t"
+	    "movw %5, %%gs\n\t"
+	    "movw %5, %%ss\n"
+	    : "=&S" (d0), "=&D" (d1), "=&c" (d2)
+	    : "m" (gdtarg), "n" (RELOC_CS), "q" ((unsigned short) RELOC_DS),
+	    "0" (&_start), "1" (new_base), "2" (prog_size));
+
+    virt_offset = new_offset;
+    debug("ok\n");
+}
+
+#if 0
+/* Copy GDT to new location and reload it */
+void move_gdt(unsigned long newgdt)
+{
+    struct gdtarg gdtarg;
+
+    debug("Moving GDT to %#lx...", newgdt);
+    memcpy(phys_to_virt(newgdt), gdt, sizeof gdt);
+    gdtarg.base = newgdt;
+    gdtarg.limit = GDT_LIMIT;
+    debug("reloading GDT...");
+    __asm__ __volatile__ ("lgdt %0\n\t" : : "m" (gdtarg));
+    debug("reloading CS for fun...");
+    __asm__ __volatile__ ("ljmp %0, $1f\n1:" : : "n" (RELOC_CS));
+    debug("ok\n");
+}
+#endif