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-rw-r--r--sys/amd64/amd64/machdep.c124
-rw-r--r--sys/i386/i386/machdep.c124
2 files changed, 156 insertions, 92 deletions
diff --git a/sys/amd64/amd64/machdep.c b/sys/amd64/amd64/machdep.c
index 4e09e32..181463e 100644
--- a/sys/amd64/amd64/machdep.c
+++ b/sys/amd64/amd64/machdep.c
@@ -1467,6 +1467,7 @@ static void
getmemsize(int first)
{
int i, physmap_idx, pa_indx;
+ int hasbrokenint12;
u_int basemem, extmem;
struct vm86frame vmf;
struct vm86context vmc;
@@ -1475,11 +1476,66 @@ getmemsize(int first)
char *cp;
struct bios_smap *smap;
+ hasbrokenint12 = 0;
+ TUNABLE_INT_FETCH("hw.hasbrokenint12", &hasbrokenint12);
bzero(&vmf, sizeof(struct vm86frame));
bzero(physmap, sizeof(physmap));
basemem = 0;
/*
+ * Some newer BIOSes has broken INT 12H implementation which cause
+ * kernel panic immediately. In this case, we need to scan SMAP
+ * with INT 15:E820 first, then determine base memory size.
+ */
+ if (hasbrokenint12) {
+ goto int15e820;
+ }
+
+ /*
+ * Perform "base memory" related probes & setup
+ */
+ vm86_intcall(0x12, &vmf);
+ basemem = vmf.vmf_ax;
+ if (basemem > 640) {
+ printf("Preposterous BIOS basemem of %uK, truncating to 640K\n",
+ basemem);
+ basemem = 640;
+ }
+
+ /*
+ * XXX if biosbasemem is now < 640, there is a `hole'
+ * between the end of base memory and the start of
+ * ISA memory. The hole may be empty or it may
+ * contain BIOS code or data. Map it read/write so
+ * that the BIOS can write to it. (Memory from 0 to
+ * the physical end of the kernel is mapped read-only
+ * to begin with and then parts of it are remapped.
+ * The parts that aren't remapped form holes that
+ * remain read-only and are unused by the kernel.
+ * The base memory area is below the physical end of
+ * the kernel and right now forms a read-only hole.
+ * The part of it from PAGE_SIZE to
+ * (trunc_page(biosbasemem * 1024) - 1) will be
+ * remapped and used by the kernel later.)
+ *
+ * This code is similar to the code used in
+ * pmap_mapdev, but since no memory needs to be
+ * allocated we simply change the mapping.
+ */
+ for (pa = trunc_page(basemem * 1024);
+ pa < ISA_HOLE_START; pa += PAGE_SIZE)
+ pmap_kenter(KERNBASE + pa, pa);
+
+ /*
+ * if basemem != 640, map pages r/w into vm86 page table so
+ * that the bios can scribble on it.
+ */
+ pte = (pt_entry_t *)vm86paddr;
+ for (i = basemem / 4; i < 160; i++)
+ pte[i] = (i << PAGE_SHIFT) | PG_V | PG_RW | PG_U;
+
+int15e820:
+ /*
* map page 1 R/W into the kernel page table so we can use it
* as a buffer. The kernel will unmap this page later.
*/
@@ -1547,58 +1603,34 @@ next_run: ;
} while (vmf.vmf_ebx != 0);
/*
- * Perform "base memory" related probes & setup
+ * Perform "base memory" related probes & setup based on SMAP
*/
- for (i = 0; i <= physmap_idx; i += 2) {
- if (physmap[i] == 0x00000000) {
- basemem = physmap[i + 1] / 1024;
- break;
+ if (basemem == 0) {
+ for (i = 0; i <= physmap_idx; i += 2) {
+ if (physmap[i] == 0x00000000) {
+ basemem = physmap[i + 1] / 1024;
+ break;
+ }
}
- }
- /* Fall back to the old compatibility function for base memory */
- if (basemem == 0) {
- vm86_intcall(0x12, &vmf);
- basemem = vmf.vmf_ax;
- }
+ if (basemem == 0) {
+ basemem = 640;
+ }
- if (basemem > 640) {
- printf("Preposterous BIOS basemem of %uK, truncating to 640K\n",
- basemem);
- basemem = 640;
- }
+ if (basemem > 640) {
+ printf("Preposterous BIOS basemem of %uK, truncating to 640K\n",
+ basemem);
+ basemem = 640;
+ }
- /*
- * XXX if biosbasemem is now < 640, there is a `hole'
- * between the end of base memory and the start of
- * ISA memory. The hole may be empty or it may
- * contain BIOS code or data. Map it read/write so
- * that the BIOS can write to it. (Memory from 0 to
- * the physical end of the kernel is mapped read-only
- * to begin with and then parts of it are remapped.
- * The parts that aren't remapped form holes that
- * remain read-only and are unused by the kernel.
- * The base memory area is below the physical end of
- * the kernel and right now forms a read-only hole.
- * The part of it from PAGE_SIZE to
- * (trunc_page(biosbasemem * 1024) - 1) will be
- * remapped and used by the kernel later.)
- *
- * This code is similar to the code used in
- * pmap_mapdev, but since no memory needs to be
- * allocated we simply change the mapping.
- */
- for (pa = trunc_page(basemem * 1024);
- pa < ISA_HOLE_START; pa += PAGE_SIZE)
- pmap_kenter(KERNBASE + pa, pa);
+ for (pa = trunc_page(basemem * 1024);
+ pa < ISA_HOLE_START; pa += PAGE_SIZE)
+ pmap_kenter(KERNBASE + pa, pa);
- /*
- * if basemem != 640, map pages r/w into vm86 page table so
- * that the bios can scribble on it.
- */
- pte = (pt_entry_t *)vm86paddr;
- for (i = basemem / 4; i < 160; i++)
- pte[i] = (i << PAGE_SHIFT) | PG_V | PG_RW | PG_U;
+ pte = (pt_entry_t *)vm86paddr;
+ for (i = basemem / 4; i < 160; i++)
+ pte[i] = (i << PAGE_SHIFT) | PG_V | PG_RW | PG_U;
+ }
if (physmap[1] != 0)
goto physmap_done;
diff --git a/sys/i386/i386/machdep.c b/sys/i386/i386/machdep.c
index 4e09e32..181463e 100644
--- a/sys/i386/i386/machdep.c
+++ b/sys/i386/i386/machdep.c
@@ -1467,6 +1467,7 @@ static void
getmemsize(int first)
{
int i, physmap_idx, pa_indx;
+ int hasbrokenint12;
u_int basemem, extmem;
struct vm86frame vmf;
struct vm86context vmc;
@@ -1475,11 +1476,66 @@ getmemsize(int first)
char *cp;
struct bios_smap *smap;
+ hasbrokenint12 = 0;
+ TUNABLE_INT_FETCH("hw.hasbrokenint12", &hasbrokenint12);
bzero(&vmf, sizeof(struct vm86frame));
bzero(physmap, sizeof(physmap));
basemem = 0;
/*
+ * Some newer BIOSes has broken INT 12H implementation which cause
+ * kernel panic immediately. In this case, we need to scan SMAP
+ * with INT 15:E820 first, then determine base memory size.
+ */
+ if (hasbrokenint12) {
+ goto int15e820;
+ }
+
+ /*
+ * Perform "base memory" related probes & setup
+ */
+ vm86_intcall(0x12, &vmf);
+ basemem = vmf.vmf_ax;
+ if (basemem > 640) {
+ printf("Preposterous BIOS basemem of %uK, truncating to 640K\n",
+ basemem);
+ basemem = 640;
+ }
+
+ /*
+ * XXX if biosbasemem is now < 640, there is a `hole'
+ * between the end of base memory and the start of
+ * ISA memory. The hole may be empty or it may
+ * contain BIOS code or data. Map it read/write so
+ * that the BIOS can write to it. (Memory from 0 to
+ * the physical end of the kernel is mapped read-only
+ * to begin with and then parts of it are remapped.
+ * The parts that aren't remapped form holes that
+ * remain read-only and are unused by the kernel.
+ * The base memory area is below the physical end of
+ * the kernel and right now forms a read-only hole.
+ * The part of it from PAGE_SIZE to
+ * (trunc_page(biosbasemem * 1024) - 1) will be
+ * remapped and used by the kernel later.)
+ *
+ * This code is similar to the code used in
+ * pmap_mapdev, but since no memory needs to be
+ * allocated we simply change the mapping.
+ */
+ for (pa = trunc_page(basemem * 1024);
+ pa < ISA_HOLE_START; pa += PAGE_SIZE)
+ pmap_kenter(KERNBASE + pa, pa);
+
+ /*
+ * if basemem != 640, map pages r/w into vm86 page table so
+ * that the bios can scribble on it.
+ */
+ pte = (pt_entry_t *)vm86paddr;
+ for (i = basemem / 4; i < 160; i++)
+ pte[i] = (i << PAGE_SHIFT) | PG_V | PG_RW | PG_U;
+
+int15e820:
+ /*
* map page 1 R/W into the kernel page table so we can use it
* as a buffer. The kernel will unmap this page later.
*/
@@ -1547,58 +1603,34 @@ next_run: ;
} while (vmf.vmf_ebx != 0);
/*
- * Perform "base memory" related probes & setup
+ * Perform "base memory" related probes & setup based on SMAP
*/
- for (i = 0; i <= physmap_idx; i += 2) {
- if (physmap[i] == 0x00000000) {
- basemem = physmap[i + 1] / 1024;
- break;
+ if (basemem == 0) {
+ for (i = 0; i <= physmap_idx; i += 2) {
+ if (physmap[i] == 0x00000000) {
+ basemem = physmap[i + 1] / 1024;
+ break;
+ }
}
- }
- /* Fall back to the old compatibility function for base memory */
- if (basemem == 0) {
- vm86_intcall(0x12, &vmf);
- basemem = vmf.vmf_ax;
- }
+ if (basemem == 0) {
+ basemem = 640;
+ }
- if (basemem > 640) {
- printf("Preposterous BIOS basemem of %uK, truncating to 640K\n",
- basemem);
- basemem = 640;
- }
+ if (basemem > 640) {
+ printf("Preposterous BIOS basemem of %uK, truncating to 640K\n",
+ basemem);
+ basemem = 640;
+ }
- /*
- * XXX if biosbasemem is now < 640, there is a `hole'
- * between the end of base memory and the start of
- * ISA memory. The hole may be empty or it may
- * contain BIOS code or data. Map it read/write so
- * that the BIOS can write to it. (Memory from 0 to
- * the physical end of the kernel is mapped read-only
- * to begin with and then parts of it are remapped.
- * The parts that aren't remapped form holes that
- * remain read-only and are unused by the kernel.
- * The base memory area is below the physical end of
- * the kernel and right now forms a read-only hole.
- * The part of it from PAGE_SIZE to
- * (trunc_page(biosbasemem * 1024) - 1) will be
- * remapped and used by the kernel later.)
- *
- * This code is similar to the code used in
- * pmap_mapdev, but since no memory needs to be
- * allocated we simply change the mapping.
- */
- for (pa = trunc_page(basemem * 1024);
- pa < ISA_HOLE_START; pa += PAGE_SIZE)
- pmap_kenter(KERNBASE + pa, pa);
+ for (pa = trunc_page(basemem * 1024);
+ pa < ISA_HOLE_START; pa += PAGE_SIZE)
+ pmap_kenter(KERNBASE + pa, pa);
- /*
- * if basemem != 640, map pages r/w into vm86 page table so
- * that the bios can scribble on it.
- */
- pte = (pt_entry_t *)vm86paddr;
- for (i = basemem / 4; i < 160; i++)
- pte[i] = (i << PAGE_SHIFT) | PG_V | PG_RW | PG_U;
+ pte = (pt_entry_t *)vm86paddr;
+ for (i = basemem / 4; i < 160; i++)
+ pte[i] = (i << PAGE_SHIFT) | PG_V | PG_RW | PG_U;
+ }
if (physmap[1] != 0)
goto physmap_done;
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