blob: df176ee48146ab805193625f046613e5021eb0da [file] [log] [blame]
// SPDX-License-Identifier: GPL-2.0+
/*
* Check RISC-V boot hart ID
*
* Copyright 2022, Heinrich Schuchardt <xypron.glpk@gmx.de>
*
* This test program reads the boot HART ID both from the device-tree from the
* RISCV_EFI_BOOT_PROTOCOL and writes both values to the console.
*/
#include <efi_api.h>
#include <efi_riscv.h>
#include <linux/libfdt.h>
static const efi_guid_t riscv_efi_boot_protocol_guid =
RISCV_EFI_BOOT_PROTOCOL_GUID;
static const efi_guid_t fdt_guid = EFI_FDT_GUID;
static struct efi_system_table *systable;
static struct efi_boot_services *boottime;
static struct efi_simple_text_output_protocol *con_out;
static const char *fdt;
/**
* Print an unsigned 32bit value as decimal number to an u16 string
*
* @value: value to be printed
* @buf: pointer to buffer address
*/
static void uint2dec(u32 value, u16 *buf)
{
u16 *pos = buf;
int i;
u16 c;
u64 f;
/*
* Increment by .5 and multiply with
* (2 << 60) / 1,000,000,000 = 0x44B82FA0.9B5A52CC
* to move the first digit to bit 60-63.
*/
f = 0x225C17D0;
f += (0x9B5A52DULL * value) >> 28;
f += 0x44B82FA0ULL * value;
for (i = 0; i < 10; ++i) {
/* Write current digit */
c = f >> 60;
if (c || pos != buf)
*pos++ = c + '0';
/* Eliminate current digit */
f &= 0xfffffffffffffff;
/* Get next digit */
f *= 0xaULL;
}
if (pos == buf)
*pos++ = '0';
*pos = 0;
}
/**
* f2h() - convert FDT value to host endianness.
*
* UEFI code is always low endian. The FDT is big endian.
*
* @val: FDT value
* Return: converted value
*/
static uint32_t f2h(fdt32_t val)
{
char *buf = (char *)&val;
char i;
/* Swap the bytes */
i = buf[0]; buf[0] = buf[3]; buf[3] = i;
i = buf[1]; buf[1] = buf[2]; buf[2] = i;
return val;
}
/**
* memcomp() - compare two memory buffers
*
* s1: first buffer
* s2: second buffer
* n: size of buffers
* Return: 0 if both buffers have the same content
*/
static int memcomp(const void *s1, const void *s2, size_t n)
{
const char *pos1 = s1, *pos2 = s2;
for (size_t count = 0; count < n ; ++pos1, ++pos2, --count) {
if (*pos1 != *pos2)
return *pos1 - *pos2;
}
return 0;
}
/**
* strcomp() - compare to strings
*
* @buf1: first string
* @buf2: second string
* Return: 0 if both strings are the same
*/
static int strcomp(const char *buf1, const char *buf2)
{
for (; *buf1 || *buf2; ++buf1, ++buf2) {
if (*buf1 != *buf2)
return *buf1 - *buf2;
}
return 0;
}
/**
* get_property() - return value of a property of an FDT node
*
* A property of the root node or one of its direct children can be
* retrieved.
*
* @property name of the property
* @node name of the node or NULL for root node
* Return: value of the property
*/
static char *get_property(const char *property, const char *node)
{
struct fdt_header *header = (struct fdt_header *)fdt;
const fdt32_t *end;
const fdt32_t *pos;
const char *strings;
size_t level = 0;
const char *nodelabel = NULL;
if (!header) {
con_out->output_string(con_out, u"Missing device tree\r\n");
return NULL;
}
if (f2h(header->magic) != FDT_MAGIC) {
con_out->output_string(con_out, u"Wrong device tree magic\r\n");
return NULL;
}
pos = (fdt32_t *)(fdt + f2h(header->off_dt_struct));
end = &pos[f2h(header->totalsize) >> 2];
strings = fdt + f2h(header->off_dt_strings);
for (; pos < end;) {
switch (f2h(pos[0])) {
case FDT_BEGIN_NODE: {
const char *c = (char *)&pos[1];
size_t i;
if (level == 1)
nodelabel = c;
++level;
for (i = 0; c[i]; ++i)
;
pos = &pos[2 + (i >> 2)];
break;
}
case FDT_PROP: {
struct fdt_property *prop = (struct fdt_property *)pos;
const char *label = &strings[f2h(prop->nameoff)];
efi_status_t ret;
/* Check if this is the property to be returned */
if (!strcomp(property, label) &&
((level == 1 && !node) ||
(level == 2 && node &&
!strcomp(node, nodelabel)))) {
char *str;
efi_uintn_t len = f2h(prop->len);
if (!len)
return NULL;
/*
* The string might not be 0 terminated.
* It is safer to make a copy.
*/
ret = boottime->allocate_pool(
EFI_LOADER_DATA, len + 1,
(void **)&str);
if (ret != EFI_SUCCESS) {
con_out->output_string(
con_out,
u"AllocatePool failed\r\n");
return NULL;
}
boottime->copy_mem(str, &pos[3], len);
str[len] = 0;
return str;
}
pos = &pos[3 + ((f2h(prop->len) + 3) >> 2)];
break;
}
case FDT_NOP:
++pos;
break;
case FDT_END_NODE:
--level;
++pos;
break;
case FDT_END:
return NULL;
default:
con_out->output_string(
con_out, u"Invalid device tree token\r\n");
return NULL;
}
}
con_out->output_string(
con_out, u"Missing FDT_END token\r\n");
return NULL;
}
/**
* get_config_table() - get configuration table
*
* @guid: table GUID
* Return: pointer to table or NULL
*/
static void *get_config_table(const efi_guid_t *guid)
{
size_t i;
for (i = 0; i < systable->nr_tables; i++) {
if (!memcomp(guid, &systable->tables[i].guid, 16))
return systable->tables[i].table;
}
return NULL;
}
/**
* fdt_get_hart() - get hart ID via RISC-V device-tree
*
* @hartid: boot hart ID
* Return: status code
*/
static efi_status_t fdt_get_hart(efi_uintn_t *hartid)
{
char *str;
fdt = get_config_table(&fdt_guid);
if (!fdt) {
con_out->output_string(con_out, u"Missing device tree\r\n");
return EFI_NOT_FOUND;
}
str = get_property("boot-hartid", "chosen");
if (!str) {
con_out->output_string(con_out,
u"/chosen/boot-hartid missing\r\n");
return EFI_NOT_FOUND;
}
*hartid = f2h(*(fdt32_t *)str);
boottime->free_pool(str);
return EFI_SUCCESS;
}
/**
* prot_get_hart() - get hart ID via RISC-V Boot Protocol
*
* @hartid: boot hart ID
* Return: status code
*/
static efi_status_t prot_get_hart(efi_uintn_t *hartid)
{
efi_status_t ret;
struct riscv_efi_boot_protocol *prot;
/* Get RISC-V boot protocol */
ret = boottime->locate_protocol(&riscv_efi_boot_protocol_guid, NULL,
(void **)&prot);
if (ret != EFI_SUCCESS) {
con_out->output_string(
con_out, u"RISC-V Boot Protocol not available\r\n");
return ret;
}
/* Get boot hart ID from EFI protocol */
ret = prot->get_boot_hartid(prot, hartid);
if (ret != EFI_SUCCESS)
con_out->output_string(con_out,
u"Could not retrieve boot hart ID\r\n");
return ret;
}
/**
* efi_main() - entry point of the EFI application.
*
* @handle: handle of the loaded image
* @systab: system table
* Return: status code
*/
efi_status_t EFIAPI efi_main(efi_handle_t handle,
struct efi_system_table *systab)
{
efi_status_t ret;
efi_uintn_t hartid;
u16 buf[16];
systable = systab;
boottime = systable->boottime;
con_out = systable->con_out;
con_out->output_string(con_out,
u"\r\nBoot hart ID\r\n------------\r\n\r\n");
ret = fdt_get_hart(&hartid);
if (ret == EFI_SUCCESS) {
con_out->output_string(con_out, u"Device-tree: ");
uint2dec(hartid, buf);
con_out->output_string(con_out, buf);
con_out->output_string(con_out, u"\r\n");
}
ret = prot_get_hart(&hartid);
if (ret == EFI_SUCCESS) {
con_out->output_string(con_out, u"RISCV_EFI_BOOT_PROTOCOL: ");
uint2dec(hartid, buf);
con_out->output_string(con_out, buf);
con_out->output_string(con_out, u"\r\n");
}
con_out->output_string(con_out, u"\r\n");
boottime->exit(handle, EFI_SUCCESS, 0, NULL);
/* We should never arrive here */
return EFI_SUCCESS;
}