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rpi400: request maximum clock speed at startup

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This commit is contained in:
K. Lange 2022-02-16 19:43:25 +09:00
parent 7fc07996d1
commit 4c13c92180
1 changed files with 52 additions and 1 deletions
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53
kernel/arch/aarch64/rpi400/main.c
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@ -46,9 +46,9 @@ void * malloc(size_t x) {
while (1);
}
#define MB(j) mbox[i++] = j
int rpi_fb_init(void) {
int i = 0;
#define MB(j) mbox[i++] = j
MB(35 * 4);
MB(MBOX_REQUEST);
@ -122,6 +122,55 @@ int rpi_fb_init(void) {
return 1;
}
void rpi_cpu_freq(void) {
int max_rate = 0;
{
int i = 0;
MB(13 * 4);
MB(MBOX_REQUEST);
MB(0x30004);
MB(8);
MB(0);
MB(3); /* arm core */
int max_hz = i;
MB(0);
MB(0x30047);
MB(8);
MB(0);
MB(3); /* arm core */
int cur_hz = i;
MB(0);
MB(0);
mbox_call(8);
printf("bootstub: max clock rate is %u Hz, current is %u Hz\n", mbox[max_hz], mbox[cur_hz]);
max_rate = mbox[max_hz];
}
if (max_rate) {
int i = 0;
MB(9 * 4);
MB(MBOX_REQUEST);
MB(0x38002);
MB(12);
MB(0);
MB(3);
int rate = i;
MB(max_rate);
MB(0); /* do not skip turbo setting */
MB(0);
mbox_call(8);
printf("bootstub: clock rate set to %u Hz\n", mbox[rate]);
}
}
extern char _kernel_start[];
extern char _kernel_end[];
extern char _ramdisk_start[];
@ -351,6 +400,8 @@ void kmain(uint32_t dtb_address, uint32_t base_addr) {
(uintptr_t)&_ramdisk_start,
(size_t)((uintptr_t)&_ramdisk_end - (uintptr_t)&_ramdisk_start));
rpi_cpu_freq();
bootstub_exit_el2();
bootstub_mmu_init();