Import sources from 2011-03-30 iso image

1 files changed, 155 insertions, 0 deletions

diff --git a/sys/src/9/pc/bios32.c b/sys/src/9/pc/bios32.c
new file mode 100755
index 000000000..e0858b9ab
--- /dev/null
+++ b/sys/src/9/pc/bios32.c
@@ -0,0 +1,155 @@
+#include "u.h"
+#include "../port/lib.h"
+#include "mem.h"
+#include "dat.h"
+#include "fns.h"
+#include "io.h"
+
+#define VFLAG(...)	if(vflag) print(__VA_ARGS__)
+
+#define BIOSSEG(a)	KADDR(((uint)(a))<<4)
+#define UPTR2INT(p)	((uintptr)(p))
+
+#define l16get(p)	(((p)[1]<<8)|(p)[0])
+#define l32get(p)	(((u32int)l16get(p+2)<<16)|l16get(p))
+
+static int vflag = 0;
+
+typedef struct BIOS32sdh {		/* BIOS32 Service Directory Header */
+	u8int	signature[4];		/* "_32_" */
+	u8int	physaddr[4];		/* physical address of entry point */
+	u8int	revision;
+	u8int	length;			/* of header in paragraphs */
+	u8int	checksum;		/* */
+	u8int	reserved[5];
+} BIOS32sdh;
+
+typedef struct BIOS32si {		/* BIOS32 Service Interface */
+	u8int*	base;			/* base address of service */
+	int	length;			/* length of service */
+	u32int	offset;			/* service entry-point from base */
+
+	u16int	ptr[3];			/* far pointer m16:32 */
+} BIOS32si;
+
+static Lock bios32lock;
+static u16int bios32ptr[3];
+static void* bios32entry;
+
+int
+bios32ci(BIOS32si* si, BIOS32ci* ci)
+{
+	int r;
+
+	lock(&bios32lock);
+	r = bios32call(ci, si->ptr);
+	unlock(&bios32lock);
+
+	return r;
+}
+
+static void*
+rsdchecksum(void* addr, int length)
+{
+	u8int *p, sum;
+
+	sum = 0;
+	for(p = addr; length-- > 0; p++)
+		sum += *p;
+	if(sum == 0)
+		return addr;
+
+	return nil;
+}
+
+static void*
+rsdscan(u8int* addr, int len, char* signature)
+{
+	int sl;
+	u8int *e, *p;
+
+	e = addr+len;
+	sl = strlen(signature);
+	for(p = addr; p+sl < e; p += 16){
+		if(memcmp(p, signature, sl))
+			continue;
+		return p;
+	}
+
+	return nil;
+}
+
+static int
+bios32locate(void)
+{
+	uintptr ptr;
+	BIOS32sdh *sdh;
+
+	VFLAG("bios32link\n");
+	if((sdh = rsdscan(BIOSSEG(0xE000), 0x20000, "_32_")) == nil)
+		return -1;
+	if(rsdchecksum(sdh, sizeof(BIOS32sdh)) == nil)
+		return -1;
+	VFLAG("sdh @ %#p, entry %#ux\n", sdh, l32get(sdh->physaddr));
+
+	bios32entry = vmap(l32get(sdh->physaddr), 4096+1);
+	VFLAG("entry @ %#p\n", bios32entry);
+	ptr = UPTR2INT(bios32entry);
+	bios32ptr[0] = ptr & 0xffff;
+	bios32ptr[1] = (ptr>>16) & 0xffff;
+	bios32ptr[2] = KESEL;
+	VFLAG("bios32link: ptr %ux %ux %ux\n",
+		bios32ptr[0], bios32ptr[1], bios32ptr[2]);
+
+	return 0;
+}
+
+void
+BIOS32close(BIOS32si* si)
+{
+	vunmap(si->base, si->length);
+	free(si);
+}
+
+BIOS32si*
+bios32open(char* id)
+{
+	uint ptr;
+	BIOS32ci ci;
+	BIOS32si *si;
+
+	lock(&bios32lock);
+	if(bios32ptr[2] == 0 && bios32locate() < 0){
+		unlock(&bios32lock);
+		return nil;
+	}
+
+	VFLAG("bios32si: %s\n", id);
+	memset(&ci, 0, sizeof(BIOS32ci));
+	ci.eax = (id[3]<<24|(id[2]<<16)|(id[1]<<8)|id[0]);
+
+	bios32call(&ci, bios32ptr);
+	unlock(&bios32lock);
+
+	VFLAG("bios32si: eax %ux\n", ci.eax);
+	if(ci.eax & 0xff)
+		return nil;
+	VFLAG("bios32si: base %#ux length %#ux offset %#ux\n",
+		ci.ebx, ci.ecx, ci.edx);
+
+	if((si = malloc(sizeof(BIOS32si))) == nil)
+		return nil;
+	if((si->base = vmap(ci.ebx, ci.ecx)) == nil){
+		free(si);
+		return nil;
+	}
+	si->length = ci.ecx;
+
+	ptr = UPTR2INT(si->base)+ci.edx;
+	si->ptr[0] = ptr & 0xffff;
+	si->ptr[1] = (ptr>>16) & 0xffff;
+	si->ptr[2] = KESEL;
+	VFLAG("bios32si: eax entry %ux\n", ptr);
+
+	return si;
+}