jordan/rpi4-osdev
1
0
Fork 0
mirror of https://github.com/isometimes/rpi4-osdev synced 2024-11-08 19:30:39 +00:00
Code Issues Projects Releases Packages Wiki Activity

Tried to speed up wgt03.c FPS by booting into EL1 with simple caches, and setting ARM clock to 1.5Ghz

Browse source
This commit is contained in:
Adam Greenwood-Byrne 2021-03-10 22:41:52 +00:00
parent 065f413ea7
commit 8d10ff5cc0
5 changed files with 157 additions and 7 deletions
Show stats Download patch file Download diff file Expand all files Collapse all files

28
part12-wgt/boot/boot.S
View file

@ -1,3 +1,5 @@
#include "sysregs.h"
#define LOCAL_CONTROL 0xff800000
#define LOCAL_PRESCALER 0xff800008
#define OSC_FREQ 54000000
@ -40,10 +42,23 @@ _start:
br x4
b 1b
2: // We're on the main core!
ldr x0, =SCTLR_VALUE_MMU_DISABLED
msr sctlr_el1, x0
// Set stack to start somewhere safe
mov sp, #MAIN_STACK
ldr x0, =HCR_VALUE
msr hcr_el2, x0
ldr x0, =SCR_VALUE
msr scr_el3, x0
ldr x0, =SPSR_VALUE
msr spsr_el3, x0
adr x0, el1_entry
msr elr_el3, x0
eret
el1_entry:
// Clean the BSS section
ldr x1, =__bss_start // Start address
ldr w2, =__bss_size // Size of the section
@ -52,6 +67,9 @@ _start:
sub w2, w2, #1
cbnz w2, 3b // Loop if non-zero
// Set stack to start somewhere safe
mov sp, #MAIN_STACK
// Jump to our main() routine in C (make sure it doesn't return)
4: bl main
// In case it does return, halt the master core too
@ -78,3 +96,9 @@ spin_cpu2:
.globl spin_cpu3
spin_cpu3:
.quad 0
.globl get_el
get_el:
mrs x0, CurrentEL
lsr x0, x0, #2
ret

44
part12-wgt/boot/sysregs.h Normal file
View file

@ -0,0 +1,44 @@
#ifndef _SYSREGS_H
#define _SYSREGS_H
// ***************************************
// SCTLR_EL1, System Control Register (EL1), Page 2654 of AArch64-Reference-Manual.
// ***************************************
#define SCTLR_RESERVED (3 << 28) | (3 << 22) | (1 << 20) | (1 << 11)
#define SCTLR_EE_LITTLE_ENDIAN (0 << 25)
#define SCTLR_EOE_LITTLE_ENDIAN (0 << 24)
#define SCTLR_I_CACHE_DISABLED (0 << 12)
#define SCTLR_D_CACHE_DISABLED (0 << 2)
#define SCTLR_I_CACHE_ENABLED (1 << 12)
#define SCTLR_D_CACHE_ENABLED (1 << 2)
#define SCTLR_MMU_DISABLED (0 << 0)
#define SCTLR_MMU_ENABLED (1 << 0)
#define SCTLR_VALUE_MMU_DISABLED (SCTLR_RESERVED | SCTLR_EE_LITTLE_ENDIAN | SCTLR_I_CACHE_ENABLED | SCTLR_D_CACHE_ENABLED | SCTLR_MMU_DISABLED)
// ***************************************
// HCR_EL2, Hypervisor Configuration Register (EL2), Page 2487 of AArch64-Reference-Manual.
// ***************************************
#define HCR_RW (1 << 31)
#define HCR_VALUE HCR_RW
// ***************************************
// SCR_EL3, Secure Configuration Register (EL3), Page 2648 of AArch64-Reference-Manual.
// ***************************************
#define SCR_RESERVED (3 << 4)
#define SCR_RW (1 << 10)
#define SCR_NS (1 << 0)
#define SCR_VALUE (SCR_RESERVED | SCR_RW | SCR_NS)
// ***************************************
// SPSR_EL3, Saved Program Status Register (EL3) Page 389 of AArch64-Reference-Manual.
// ***************************************
#define SPSR_MASK_ALL (7 << 6)
#define SPSR_EL1h (5 << 0)
#define SPSR_VALUE (SPSR_MASK_ALL | SPSR_EL1h)
#endif

82
part12-wgt/examples/wgt03.c
View file

@ -1,4 +1,6 @@
#include "wgt.h"
#include "include/mem.h"
#include "include/mb.h"
// ######## REQUIRED FUNCTIONS ########
@ -57,6 +59,8 @@ int clearcount; /* Counts the number of screen clears. */
int curx = 0;
int cury = 0;
extern int get_el(void);
void debugstr(char *str) {
if (curx + (strlen(str) * 8) >= 1920) {
curx = 0; cury += 8;
@ -96,6 +100,64 @@ void debughex(unsigned int d) {
debugstr(" ");
}
int get_max_clock()
{
mbox[0] = 8*4; // Length of message in bytes
mbox[1] = MBOX_REQUEST;
mbox[2] = MBOX_TAG_GETCLKMAXM; // Tag identifier
mbox[3] = 8; // Value size in bytes
mbox[4] = 0; // Value size in bytes
mbox[5] = 0x3; // Value
mbox[6] = 0; // Rate
mbox[7] = MBOX_TAG_LAST;
if (mbox_call(MBOX_CH_PROP)) {
if (mbox[5] == 0x3) {
return mbox[6];
}
}
return 0;
}
int get_clock_rate()
{
mbox[0] = 8*4; // Length of message in bytes
mbox[1] = MBOX_REQUEST;
mbox[2] = MBOX_TAG_GETCLKRATE; // Tag identifier
mbox[3] = 8; // Value size in bytes
mbox[4] = 0; // Value size in bytes
mbox[5] = 0x3; // Value
mbox[6] = 0; // Rate
mbox[7] = MBOX_TAG_LAST;
if (mbox_call(MBOX_CH_PROP)) {
if (mbox[5] == 0x3) {
return mbox[6];
}
}
return 0;
}
int set_clock_rate(unsigned int rate)
{
mbox[0] = 9*4; // Length of message in bytes
mbox[1] = MBOX_REQUEST;
mbox[2] = MBOX_TAG_SETCLKRATE; // Tag identifier
mbox[3] = 12; // Value size in bytes
mbox[4] = 0; // Value size in bytes
mbox[5] = 0x3; // Value
mbox[6] = rate; // Rate
mbox[7] = 0; // Rate
mbox[8] = MBOX_TAG_LAST;
if (mbox_call(MBOX_CH_PROP)) {
if (mbox[5] == 0x3 && mbox[6] == rate) {
return 1;
}
}
return 0;
}
void timer_routine (void)
{
timer++;
@ -103,13 +165,20 @@ void timer_routine (void)
void wgt03()
{
mem_init();
vga256 (); /* Initialize WGT system */
debugstr ("WGT Example #3"); debugcrlf(); debugcrlf();
debugstr ("This program will use the wcls routine to clear the screen"); debugcrlf();
debugstr ("using random colors as fast as it can until you press a key."); debugcrlf();
debugstr ("It will then report the highest frame rate possible on your computer."); debugcrlf(); debugcrlf(); debugcrlf();
debugstr ("Press any key to continue."); debugcrlf();
int el = get_el();
debugstr("Exception level: "); debughex(el); debugcrlf();
int setter = set_clock_rate(get_max_clock());
debugstr("Set clock returned "); debughex(setter); debugcrlf(); debugcrlf(); debugcrlf();
debugstr ("Press any key to continue.");
getch ();
clearcount = 0;
@ -134,10 +203,17 @@ void wgt03()
wcls(vgapal[0]);
int clock = get_clock_rate();
debugstr("Clock rate: "); debughex(clock); debugcrlf();
int maxclock = get_max_clock();
debugstr("Max clock rate: "); debughex(maxclock); debugcrlf();
unsigned int fps = clearcount / (timer / TIMERSPEED);
debughex(fps); debugstr("frames per second"); debugcrlf();
debughex(fps); debugstr("frames per second"); debugcrlf(); debugcrlf(); debugcrlf();
debugstr ("This is the highest frame rate your computer can produce for full screen\n"); debugcrlf();
debugstr ("animation."); debugcrlf();
debugstr ("animation.");
}
void main()

5
part12-wgt/include/mb.h
View file

@ -1,3 +1,5 @@
#pragma once
extern volatile unsigned int mbox[36];
enum {
@ -18,6 +20,9 @@ enum {
enum {
MBOX_TAG_SETPOWER = 0x28001,
MBOX_TAG_GETCLKRATE = 0x30002,
MBOX_TAG_GETCLKMAXM = 0x30004,
MBOX_TAG_SETCLKRATE = 0x38002,
MBOX_TAG_SETPHYWH = 0x48003,

5
part12-wgt/lib/mem.c
View file

@ -2,8 +2,9 @@ extern unsigned char _end[];
// Define the heap
unsigned char *HEAP_START = &_end[0];
unsigned int HEAP_SIZE = 0x30000000; // Max heap size is 768Mb
// unsigned char *HEAP_START = &_end[0]; // End of kernel
unsigned char *HEAP_START = (unsigned char *)0x400000; // Top of stack
unsigned int HEAP_SIZE = 0x30000000; // Max heap size is 764Mb
unsigned char *HEAP_END;
// Set up some globals