lk/platform/bcm28xx/platform.c

/*
 * Copyright (c) 2015 Travis Geiselbrecht
 *
 * Use of this source code is governed by a MIT-style
 * license that can be found in the LICENSE file or at
 * https://opensource.org/licenses/MIT
 */
#include <lk/reg.h>
#include <lk/err.h>
#include <lk/debug.h>
#include <lk/trace.h>

#include <dev/uart.h>
#include <arch.h>
#include <lk/init.h>
#include <kernel/vm.h>
#include <kernel/spinlock.h>
#include <dev/timer/arm_generic.h>
#include <platform.h>
#include <platform/interrupts.h>
#include <platform/bcm28xx.h>

#if BCM2836
#include <arch/arm.h>
#include <arch/arm/mmu.h>

/* initial memory mappings. parsed by start.S */
struct mmu_initial_mapping mmu_initial_mappings[] = {
    /* 1GB of sdram space */
    {
        .phys = SDRAM_BASE,
        .virt = KERNEL_BASE,
        .size = MEMSIZE,
        .flags = 0,
        .name = "memory"
    },

    /* peripherals */
    {
        .phys = BCM_PERIPH_BASE_PHYS,
        .virt = BCM_PERIPH_BASE_VIRT,
        .size = BCM_PERIPH_SIZE,
        .flags = MMU_INITIAL_MAPPING_FLAG_DEVICE,
        .name = "bcm peripherals"
    },

    /* identity map to let the boot code run */
    {
        .phys = SDRAM_BASE,
        .virt = SDRAM_BASE,
        .size = 16*1024*1024,
        .flags = MMU_INITIAL_MAPPING_TEMPORARY
    },
    /* null entry to terminate the list */
    { 0 }
};

extern void arm_reset(void);

#define DEBUG_UART 0

#elif BCM2837
#include <libfdt.h>
#include <arch/arm64.h>
#include <arch/arm64/mmu.h>
#include <platform/mailbox.h>

/* initial memory mappings. parsed by start.S */
struct mmu_initial_mapping mmu_initial_mappings[] = {
    /* 1GB of sdram space */
    {
        .phys = SDRAM_BASE,
        .virt = KERNEL_BASE,
        .size = MEMORY_APERTURE_SIZE,
        .flags = 0,
        .name = "memory"
    },

    /* peripherals */
    {
        .phys = BCM_PERIPH_BASE_PHYS,
        .virt = BCM_PERIPH_BASE_VIRT,
        .size = BCM_PERIPH_SIZE,
        .flags = MMU_INITIAL_MAPPING_FLAG_DEVICE,
        .name = "bcm peripherals"
    },

    /* null entry to terminate the list */
    { 0 }
};

#define DEBUG_UART 1

extern void arm64_reset(void);

#else
#error Unknown BCM28XX Variant
#endif

extern void intc_init(void);

static pmm_arena_t arena = {
    .name = "sdram",
    .base = SDRAM_BASE,
    .size = MEMSIZE,
    .flags = PMM_ARENA_FLAG_KMAP,
};

void platform_init_mmu_mappings(void) {
}

void platform_early_init(void) {
    uart_init_early();

    intc_init();

#if BCM2837
    arm_generic_timer_init(INTERRUPT_ARM_LOCAL_CNTPNSIRQ, 0);

    /* look for a flattened device tree just before the kernel */
    const void *fdt = (void *)KERNEL_BASE;
    int err = fdt_check_header(fdt);
    if (err >= 0) {
        /* walk the nodes, looking for 'memory' */
        int depth = 0;
        int offset = 0;
        for (;;) {
            offset = fdt_next_node(fdt, offset, &depth);
            if (offset < 0)
                break;

            /* get the name */
            const char *name = fdt_get_name(fdt, offset, NULL);
            if (!name)
                continue;

            /* look for the 'memory' property */
            if (strcmp(name, "memory") == 0) {
                printf("Found memory in fdt\n");
                int lenp;
                const void *prop_ptr = fdt_getprop(fdt, offset, "reg", &lenp);
                if (prop_ptr && lenp == 0x10) {
                    /* we're looking at a memory descriptor */
                    //uint64_t base = fdt64_to_cpu(*(uint64_t *)prop_ptr);
                    uint64_t len = fdt64_to_cpu(*((const uint64_t *)prop_ptr + 1));

                    /* trim size on certain platforms */
#if ARCH_ARM
                    if (len > 1024*1024*1024U) {
                        len = 1024*1024*1024; /* only use the first 1GB on ARM32 */
                        printf("trimming memory to 1GB\n");
                    }
#endif

                    /* set the size in the pmm arena */
                    arena.size = len;
                }
            }
        }
    }

#elif BCM2836
    arm_generic_timer_init(INTERRUPT_ARM_LOCAL_CNTPNSIRQ, 1000000);
#else
#error Unknown BCM28XX Variant
#endif

    /* add the main memory arena */
    pmm_add_arena(&arena);

#if BCM2837
    /* reserve the first 64k of ram, which should be holding the fdt */
    struct list_node list = LIST_INITIAL_VALUE(list);
    pmm_alloc_range(MEMBASE, 0x80000 / PAGE_SIZE, &list);
#endif

#if WITH_SMP
#if BCM2837
    // Secondary entry point for arm64 is 4 bytes into the kernel image
    uintptr_t sec_entry = (uintptr_t)(&arm64_reset) - KERNEL_ASPACE_BASE + 4;
    unsigned long long *spin_table = (void *)(KERNEL_ASPACE_BASE + 0xd8);

    for (uint i = 1; i <= 3; i++) {
        spin_table[i] = sec_entry;
        __asm__ __volatile__ ("" : : : "memory");
        arch_clean_cache_range(0xffff000000000000,256);
        __asm__ __volatile__("sev");
    }
#else
    /* start the other cpus */
    uintptr_t sec_entry = (uintptr_t)&arm_reset;
    sec_entry -= (KERNEL_BASE - MEMBASE);
    for (uint i = 1; i <= 3; i++) {
        *REG32(ARM_LOCAL_BASE + 0x8c + 0x10 * i) = sec_entry;
    }
#endif
#endif
}

void platform_init(void) {
    uart_init();
#if BCM2837
    init_framebuffer();
#endif
}

void platform_dputc(char c) {
    if (c == '\n')
        uart_putc(DEBUG_UART, '\r');
    uart_putc(DEBUG_UART, c);
}

int platform_dgetc(char *c, bool wait) {
    int ret = uart_getc(DEBUG_UART, wait);
    if (ret == -1)
        return -1;
    *c = ret;
    return 0;
}