HelenOS sources
This source file includes following definitions.
- rsdp_check
- acpi_sdt_check
- map_sdt
- configure_via_rsdt
- configure_via_xsdt
- search_rsdp
- acpi_init
#include <genarch/acpi/acpi.h>
#include <genarch/acpi/madt.h>
#include <arch/bios/bios.h>
#include <debug.h>
#include <mm/page.h>
#include <mm/km.h>
#include <log.h>
#include <memw.h>
#define RSDP_SIGNATURE      "RSD PTR "
#define RSDP_REVISION_OFFS  15
#define CMP_SIGNATURE(left, right) \
        (((left)[0] == (right)[0]) && \
        ((left)[1] == (right)[1]) && \
        ((left)[2] == (right)[2]) && \
        ((left)[3] == (right)[3]))
struct acpi_rsdp *acpi_rsdp = NULL;
struct acpi_rsdt *acpi_rsdt = NULL;
struct acpi_xsdt *acpi_xsdt = NULL;
struct acpi_signature_map signature_map[] = {
        {
                (uint8_t *) "APIC",
                (void *) &acpi_madt,
                "Multiple APIC Description Table"
        }
};
static int rsdp_check(uint8_t *_rsdp)
{
        struct acpi_rsdp *rsdp = (struct acpi_rsdp *) _rsdp;
        uint8_t sum = 0;
        uint32_t i;
        for (i = 0; i < 20; i++)
                sum = (uint8_t) (sum + _rsdp[i]);
        if (sum)
                return 0; 
        if (rsdp->revision == 0)
                return 1; 
        for (; i < rsdp->length; i++)
                sum = (uint8_t) (sum + _rsdp[i]);
        return !sum;
}
int acpi_sdt_check(uint8_t *sdt)
{
        struct acpi_sdt_header *hdr = (struct acpi_sdt_header *) sdt;
        uint8_t sum = 0;
        unsigned int i;
        for (i = 0; i < hdr->length; i++)
                sum = (uint8_t) (sum + sdt[i]);
        return !sum;
}
static struct acpi_sdt_header *map_sdt(struct acpi_sdt_header *psdt)
{
        struct acpi_sdt_header *vhdr;
        struct acpi_sdt_header *vsdt;
        
        vhdr = (struct acpi_sdt_header *) km_map((uintptr_t) psdt,
            sizeof(struct acpi_sdt_header), KM_NATURAL_ALIGNMENT,
            PAGE_READ | PAGE_NOT_CACHEABLE);
        
        vsdt = (struct acpi_sdt_header *) km_map((uintptr_t) psdt,
            vhdr->length, KM_NATURAL_ALIGNMENT,
            PAGE_WRITE | PAGE_NOT_CACHEABLE);
        
        return vsdt;
}
static void configure_via_rsdt(void)
{
        size_t i;
        size_t j;
        size_t cnt = (acpi_rsdt->header.length - sizeof(struct acpi_sdt_header)) /
            sizeof(uint32_t);
        for (i = 0; i < cnt; i++) {
                for (j = 0; j < sizeof(signature_map) /
                    sizeof(struct acpi_signature_map); j++) {
                        struct acpi_sdt_header *hdr =
                            (struct acpi_sdt_header *) (sysarg_t) acpi_rsdt->entry[i];
                        struct acpi_sdt_header *vhdr = map_sdt(hdr);
                        if (CMP_SIGNATURE(vhdr->signature, signature_map[j].signature)) {
                                if (!acpi_sdt_check((uint8_t *) vhdr))
                                        break;
                                *signature_map[j].sdt_ptr = vhdr;
                                LOG("%p: ACPI %s", *signature_map[j].sdt_ptr,
                                    signature_map[j].description);
                        }
                }
        }
}
static void configure_via_xsdt(void)
{
        size_t i;
        size_t j;
        size_t cnt = (acpi_xsdt->header.length - sizeof(struct acpi_sdt_header)) /
            sizeof(uint64_t);
        for (i = 0; i < cnt; i++) {
                for (j = 0; j < sizeof(signature_map) /
                    sizeof(struct acpi_signature_map); j++) {
                        struct acpi_sdt_header *hdr =
                            (struct acpi_sdt_header *) ((uintptr_t) acpi_xsdt->entry[i]);
                        struct acpi_sdt_header *vhdr = map_sdt(hdr);
                        if (CMP_SIGNATURE(vhdr->signature, signature_map[j].signature)) {
                                if (!acpi_sdt_check((uint8_t *) vhdr))
                                        break;
                                *signature_map[j].sdt_ptr = vhdr;
                                LOG("%p: ACPI %s", *signature_map[j].sdt_ptr,
                                    signature_map[j].description);
                        }
                }
        }
}
static uint8_t *search_rsdp(uint8_t *base, size_t len)
{
        for (size_t i = 0; i < len; i += 16) {
                if (!__builtin_memcmp(&base[i], RSDP_SIGNATURE, 8) &&
                    rsdp_check(&base[i]))
                        return &base[i];
        }
        return NULL;
}
void acpi_init(void)
{
        
        uint8_t *rsdp = NULL;
        if (ebda)
                rsdp = search_rsdp((uint8_t *) PA2KA(ebda), 1024);
        if (!rsdp)
                rsdp = search_rsdp((uint8_t *) PA2KA(0xe0000), 128 * 1024);
        if (!rsdp)
                return;
        acpi_rsdp = (struct acpi_rsdp *) rsdp;
        LOG("%p: ACPI Root System Description Pointer", acpi_rsdp);
        uintptr_t acpi_rsdt_p = (uintptr_t) acpi_rsdp->rsdt_address;
        uintptr_t acpi_xsdt_p = 0;
        if (acpi_rsdp->revision)
                acpi_xsdt_p = (uintptr_t) acpi_rsdp->xsdt_address;
        if (acpi_rsdt_p)
                acpi_rsdt = (struct acpi_rsdt *) map_sdt(
                    (struct acpi_sdt_header *) acpi_rsdt_p);
        if (acpi_xsdt_p)
                acpi_xsdt = (struct acpi_xsdt *) map_sdt(
                    (struct acpi_sdt_header *) acpi_xsdt_p);
        if ((acpi_rsdt) && (!acpi_sdt_check((uint8_t *) acpi_rsdt))) {
                log(LF_ARCH, LVL_ERROR, "RSDT: bad checksum");
                return;
        }
        if ((acpi_xsdt) && (!acpi_sdt_check((uint8_t *) acpi_xsdt))) {
                log(LF_ARCH, LVL_ERROR, "XSDT: bad checksum");
                return;
        }
        if (acpi_xsdt)
                configure_via_xsdt();
        else if (acpi_rsdt)
                configure_via_rsdt();
}
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