More elegant bios replacement

2 files changed, 26 insertions, 28 deletions

diff --git a/nvbiosemu.c b/nvbiosemu.c
index c8e0309..96c89ce 100644
--- a/nvbiosemu.c
+++ b/nvbiosemu.c
@@ -20,6 +20,8 @@
 #define TRUE true
 #define FALSE false
 #define ScrnInfoPtr void *
+
+#define VBIOS_ROM    0xc0000
 #define NV_PROM_SIZE 0x10000
 
 static uint32_t *PMC;
@@ -47,14 +49,14 @@ static void unmap_dev_mem (unsigned long Base, unsigned long Size)
 	munmap((caddr_t)(Base - alignOff), (Size + alignOff));
 }
 
-static Bool nv_cksum(const uint8_t *data, unsigned int offset, unsigned int length)
+static Bool nv_cksum(const uint8_t *data, unsigned int length)
 {
 	/* there's a few checksums in the BIOS, so here's a generic checking function */
 	int i;
 	uint8_t sum = 0;
 
 	for (i = 0; i < length; i++)
-		sum += data[offset + i];
+		sum += data[i];
 
 	if (sum)
 		return TRUE;
@@ -70,7 +72,7 @@ static Bool NVValidVBIOS(ScrnInfoPtr pScrn, const uint8_t *data)
 		return FALSE;
 	}
 
-	if (nv_cksum(data, 0, data[2] * 512)) {
+	if (nv_cksum(data, data[2] * 512)) {
 		printf("... BIOS checksum invalid\n");
 		return FALSE;
 	} else
@@ -139,27 +141,23 @@ static Bool NVShadowVBIOS(ScrnInfoPtr pScrn, uint32_t *data)
 	return FALSE;
 }
 
-int fake_bios(int fd, uint8_t *bios)
+int mmap_in_bios(uint8_t *bios)
 {
-	uint8_t *emumem, *sysmem;
-	int i;
+	int zfd, i;
 
-	/* this does not get free'd until exit */
-	if (!(emumem = malloc(1024 * 1024))) {
-		printf("Couldn't allocate fake system memory\n");
+	if ((zfd = open("/dev/zero", O_RDWR)) == -1) {
+		printf("Can't open /dev/zero\n");
 		return 1;
 	}
 
-	sysmem = map_dev_mem(fd, 0, 1024*1024);
+	mmap((void *)VBIOS_ROM, NV_PROM_SIZE,
+	     PROT_READ | PROT_WRITE | PROT_EXEC,
+	     MAP_FIXED | MAP_SHARED, zfd, 0);
 
-	for (i = 0; i < 1024*1024; i++)
-		emumem[i] = sysmem[i];
-	for (i = 0; i < NV_PROM_SIZE; i++)
-		emumem[0xc0000 + i] = bios[i];
+	close(zfd);
 
-	unmap_dev_mem((unsigned long)sysmem, 1024*1024);
-
-	M.mem_base = (uintptr_t)emumem;
+	for (i = 0; i < NV_PROM_SIZE; i++)
+		*((uint8_t *)VBIOS_ROM + i) = bios[i];
 
 	return 0;
 }
@@ -169,27 +167,27 @@ int reload_nv_bios(uintptr_t pcimemaddr)
 	int fd;
 	uint8_t bios[NV_PROM_SIZE];
 
-	if( (fd = open("/dev/mem", O_RDWR)) == -1 ) {
+	if ((fd = open("/dev/mem", O_RDWR)) == -1) {
 		printf("Can't open /dev/mem\n");
 		return 0;
 	}
 
 	printf("Using card memory region at %p\n", (void *)pcimemaddr);
 
-	PMC = map_dev_mem(fd, pcimemaddr + 0x000000, 0xffff);
+	PMC = map_dev_mem(fd, pcimemaddr + 0x000000, 0x2000);
 	PRAMIN = map_dev_mem(fd, pcimemaddr + 0x700000, NV_PROM_SIZE);
 	PROM = map_dev_mem(fd, pcimemaddr + 0x300000, NV_PROM_SIZE);
 	PNV50 = map_dev_mem(fd, pcimemaddr + 0x610000, 0xffff);
 
+	close(fd);
+
 	if (NVShadowVBIOS(NULL, (uint32_t *)bios)) {
-		if (fake_bios(fd, bios))
+		if (mmap_in_bios(bios))
 			return 1;
 	} else
 		return 1;
 
-	close(fd);
-
-	unmap_dev_mem((unsigned long)PMC, NV_PROM_SIZE);
+	unmap_dev_mem((unsigned long)PMC, 0x2000);
 	unmap_dev_mem((unsigned long)PRAMIN, NV_PROM_SIZE);
 	unmap_dev_mem((unsigned long)PROM, NV_PROM_SIZE);
 	unmap_dev_mem((unsigned long)PNV50, 0xffff);
diff --git a/thunk.c b/thunk.c
index a1c7fd3..868d597 100644
--- a/thunk.c
+++ b/thunk.c
@@ -161,20 +161,20 @@ int LRMI_init() {
 	
 	X86_EFLAGS = X86_IF_MASK | X86_IOPL_MASK;
 
-	M.mem_base = 0;
-	M.mem_size = 1024*1024;
-
 	/*
 	 * Allocate a 64k stack.
 	 */
 	stack = LRMI_alloc_real(64 * 1024);
 	X86_SS = (unsigned long)stack >> 4;
 	X86_ESP = 0xFFF9;
-	memset (M.mem_base + stack, 0, 64*1024);
+	memset (stack, 0, 64*1024);
 
 	*((char *)0) = 0x4f; /* Make sure that we end up jumping back to a
 				halt instruction */
 
+	M.mem_base = 0;
+	M.mem_size = 1024*1024;
+
 	return 1;
 }
 
@@ -210,7 +210,7 @@ int real_call(struct LRMI_regs *registers) {
 	  	X86_ESP = 0xFFF9;
 	}
 	  
-	memset (M.mem_base + stack, 0, 64*1024);
+	memset (stack, 0, 64*1024);
 
 	X86EMU_exec();