[Qemu-devel] [PATCH v2] add resolutions via command-line

[G 3]

Add the ability to add resolutions from the command-line. This patch  
works by
looking for a property called 'resolutions' in the options node of  
OpenBIOS.
If it is found all the resolutions are parsed and loaded.

Example command-line:

-prom-env resolutions=512x342,640x480,800x600,1024x600,1200x700,1440x900

Signed-off-by: John Arbuckle <address@hidden>
---
Implemented my own malloc(), strlen(), pow(), and atoi() functions.
Removed free() calls.
Changed get_set_count() to get_resolution_set_count().

 QemuVGADriver/src/QemuVga.c | 285 ++++++++++++++++++++++++++++++++++ 
+++++++++-
 1 file changed, 283 insertions(+), 2 deletions(-)

diff --git a/QemuVGADriver/src/QemuVga.c b/QemuVGADriver/src/QemuVga.c
index 4584242..cba65ba 100644
--- a/QemuVGADriver/src/QemuVga.c
+++ b/QemuVGADriver/src/QemuVga.c
@@ -18,7 +18,19 @@ static struct vMode vModes[] =  {
        { 1600, 1200 },
        { 1920, 1080 },
        { 1920, 1200 },
-       { 0,0 }
+       { 0,0 },
+       { 0,0 },
+       { 0,0 },
+       { 0,0 },
+       { 0,0 },
+       { 0,0 },
+       { 0,0 },
+       { 0,0 },
+       { 0,0 },
+       { 0,0 },
+       { 0,0 },
+       { 0,0 },
+       { 0,0 },
 };

 static void VgaWriteB(UInt16 port, UInt8 val)
@@ -148,11 +160,280 @@ static InterruptMemberNumber  
PCIInterruptHandler(InterruptSetMember ISTmember,
 #endif


+/* Returns the number of resolutions */
+static int get_number_of_resolutions()
+{
+       int size_of_array, num_of_resolutions, index;
+       
+       num_of_resolutions = 0;
+       size_of_array = sizeof(vModes) / sizeof(struct vMode);
+       
+       for(index = 0; index < size_of_array; index++)
+       {
+               if (vModes[index].width != 0) {
+                       num_of_resolutions++;
+               }
+       }
+       
+       return num_of_resolutions;
+}
+
+
+/* strlen() implementation */
+static int strlen(const char *str)
+{
+       int count = 0;
+       
+       for( ; *str != '\0'; str++) {
+               count++;        
+       }
+       
+       return count;
+}
+
+
+/* output = base^power */
+static int pow(int base, int power)
+{
+       int i, output;
+       output = 1;
+       for (i = 0; i < power; i++) {
+               output = output * base;
+       }
+       return output;
+}
+
+
+/* convert ascii string to number */
+static int atoi(const char *str)
+{
+       int result = 0, multiplier;
+
+       multiplier = strlen(str) - 1;
+       for ( ; *str != '\0'; str++) {
+               result += (*str - '0') * pow(10, multiplier);
+               multiplier--;
+               if (multiplier < 0)  /* Something might be wrong if returning 
here */
+                       return result;
+       }
+
+       return result;
+}
+
+
+/* An interesting way of emulating memory allocation. */
+static char *malloc(int size)
+{
+       const int max_buffer_size = 2000;
+       static char buffer[max_buffer_size];
+       static int free_mem_pointer = 0;
+       static Boolean first_alloc = true;
+       
+       free_mem_pointer += size;
+       if (free_mem_pointer >= max_buffer_size) {
+               return NULL;
+       }
+       
+       /* For getting the very beginning of the buffer */
+       if (first_alloc == true) {
+               first_alloc = false;
+               return buffer;
+       }
+
+       return (buffer + free_mem_pointer);
+}
+
+
+/* Get the resolution set at the specified index. */
+static char *get_resolution_set(const char *resolution_set_str, int  
set_number)
+{
+       const int max_buf_size = 100;
+       char c, *buffer;
+       int index, comma_count;
+
+       buffer = (char *) malloc(max_buf_size);
+       comma_count = 0;
+       index = 0;
+       set_number++; /* Makes things easier to understand */
+
+       c = *(resolution_set_str++);
+       while (c != '\0') {
+               buffer[index++] = c;
+               c = *(resolution_set_str++);
+               if (c == ',') {
+                       comma_count++;
+                       if (comma_count == set_number || index >= max_buf_size) 
{
+                               buffer[index] = '\0';
+                               return buffer;
+                       }
+                       
+                       else {
+                               /* reset the buffer */
+                               index = 0;
+                               c = *(resolution_set_str++);
+                       }
+               }
+       }
+       
+       buffer[index] = '\0';
+
+       return buffer;
+}
+
+
+/* Get the number of resolution sets - a set is a width by height  
pair */
+static int get_resolution_set_count(const char *resolution_sets_str)
+{
+       char c;
+       int count;
+       
+       /* Count the number of commas */
+       count = 0;
+       c = *(resolution_sets_str++);
+       while (c != '\0') {
+               if (c == ',') {
+                       count++;
+               }
+               c = *(resolution_sets_str++);
+       }
+
+       return count + 1;
+}
+
+
+/*
+ * Returns the width value of a resolution set
+ * Example:
+ * input: 16000x9000
+ * output: 16000
+ */
+static int get_width(const char *resolution_str)
+{
+       int index;
+       char c;
+       const int max_buf_size = 25;
+       char buffer[max_buf_size];
+       c = *(resolution_str++);
+       index = 0;
+       while (c != 'x' && index < max_buf_size) {
+               buffer[index++] = c;
+               c = *(resolution_str++);
+       }
+       
+       /* Terminate string */
+       buffer[index] = '\0';
+       
+       return atoi(buffer);
+}
+
+
+/*
+ * Returns the height value of a resolution set
+ * Example
+ * input: 16000x9000
+ * output: 9000
+ */
+static int get_height(const char *resolution_str)
+{
+       int index;
+       char c;
+       const int max_buf_size = 25;
+       char buffer[max_buf_size];
+       
+       /* skip to character after x */
+       while (*resolution_str != 'x') {
+               resolution_str++;
+       }
+       resolution_str++;
+       
+       /* Add digits of the height to the buffer */
+       index = 0;
+       c = *(resolution_str++);
+       while (c != '\0') {
+               buffer[index++] = c;
+               c = *(resolution_str++);
+               if(index >= max_buf_size) {
+                       break;
+               }
+       }
+       
+       /* Terminate string */
+       buffer[index] = '\0';
+       
+       return atoi(buffer);
+}
+
+
+/* Looks in the /options node for the value of the resolutions  
property */
+static int add_user_resolutions(void)
+{      
+       RegEntryID *entry_id;
+       OSErr err;
+       OSStatus os_status = noErr;
+       Boolean is_done;
+       void *value;
+       RegPropertyValueSize property_size = -1;
+       int index, res_set_count;
+       char *set_str;
+
+       #define PROPERTY_NAME "resolutions"
+       #define NODE_PATH "Devices:device-tree:options"
+
+       /* init the entry variable */
+       err = RegistryEntryIDInit(entry_id);
+       if (err != noErr) {
+               lprintf("Error: Failed to init entry variable! (Error: %d)\n", 
err);
+               return err;
+       }
+       is_done = false;
+
+       /* Get the entry ID value */
+	err = RegistryCStrEntryLookup(NULL /* start root */, NODE_PATH,  
entry_id);
+       if (err != noErr) {
+               lprintf("RegistryCStrEntryLookup() failure (Error: %d)\n", err);
+               return err;
+       }
+
+       /* Get the size of the property */
+	os_status = RegistryPropertyGetSize(entry_id, PROPERTY_NAME,  
&property_size);
+       if (os_status != noErr) {
+		lprintf("Error: Failed to get property size! (Error: %d)\n",  
os_status);
+               return os_status;
+       }
+
+       /* allocate memory to the value variable */
+       value = (void *) malloc(property_size);
+
+       /* Get the value of the property */
+	err = RegistryPropertyGet(entry_id, PROPERTY_NAME, value,  
&property_size);
+       if (err != noErr) {
+		lprintf("Error: Failed to find property value %s! (Error: %d)\n",  
PROPERTY_NAME, err);
+               return err;
+       }
+       
+	/* Limit the number of resolutions to number of available slots in  
vMode */
+       #define available_slots 20
+       res_set_count = get_resolution_set_count(value);
+	res_set_count = (res_set_count > available_slots ?  
available_slots : res_set_count);
+
+       /* Add each resolution set */
+       for(index = 0; index < res_set_count; index++) {
+               set_str = get_resolution_set(value, index);
+               vModes[index].width = get_width(set_str);
+               vModes[index].height = get_height(set_str);
+       }
+
+       return 0;
+}
+
+
 OSStatus QemuVga_Init(void)
 {
        UInt16 id, i;
        UInt32 mem, width, height, depth;

+       add_user_resolutions();
+
        lprintf("First MMIO read...\n");
        id = DispiReadW(VBE_DISPI_INDEX_ID);
        mem = DispiReadW(VBE_DISPI_INDEX_VIDEO_MEMORY_64K);
@@ -183,7 +464,7 @@ OSStatus QemuVga_Init(void)
                i = 0;
        }
        GLOBAL.bootMode = i;
-       GLOBAL.numModes = sizeof(vModes) / sizeof(struct vMode) - 1;
+       GLOBAL.numModes = get_number_of_resolutions();

        QemuVga_SetMode(GLOBAL.bootMode, depth, 0);

--
2.6.0