diff options
| -rw-r--r-- | configure.ac | 11 | ||||
| -rw-r--r-- | utils/Makefile.am | 9 | ||||
| -rw-r--r-- | utils/hooks/30-add-offb.c | 492 |
3 files changed, 512 insertions, 0 deletions
diff --git a/configure.ac b/configure.ac index c9f587e..08685ec 100644 --- a/configure.ac +++ b/configure.ac @@ -57,6 +57,16 @@ AC_CHECK_LIB([udev], [udev_new], [AC_MSG_FAILURE([The libudev development library is required by petitboot. Try installing the package libudev-dev or libudev-devel.])] ) +AC_ARG_WITH([fdt], + AS_HELP_STRING([--without-fdt], + [Build without libfdt (default: no)])) + +AS_IF([test "x$with_fdt" != "xno"], + AC_CHECK_LIB([fdt], [fdt_check_header], + [FDT_LIBS=-lfdt; have_libfdt=yes])) + +AM_CONDITIONAL([HAVE_LIBFDT], [test x"$have_libfdt" = xyes]) + AC_CHECK_HEADERS([stdarg.h]) AC_CHECK_HEADERS([varargs.h]) @@ -275,6 +285,7 @@ AS_IF( ) AC_SUBST([UDEV_LIBS]) +AC_SUBST([FDT_LIBS]) AC_SUBST([LIBTOOL_DEPS]) AC_SUBST([DESTDIR]) AC_SUBST([pkgsysconfdir], ["${sysconfdir}/${package}"]) diff --git a/utils/Makefile.am b/utils/Makefile.am index 9b36619..403f46d 100644 --- a/utils/Makefile.am +++ b/utils/Makefile.am @@ -19,6 +19,15 @@ sbin_PROGRAMS += utils/pb-event utils/pb-config utils_pb_config_LDADD = $(top_builddir)/lib/libpbcore.la \ $(top_builddir)/discover/platform.ro +utils_hooks_30_add_offb_SOURCES = utils/hooks/30-add-offb.c +utils_hooks_30_add_offb_LDADD = $(top_builddir)/lib/libpbcore.la \ + $(FDT_LIBS) + +if HAVE_LIBFDT +noinst_PROGRAMS = \ + utils/hooks/30-add-offb +endif + dist_pkgdata_DATA = \ utils/kboot.conf.sample \ utils/bb-kexec-reboot \ diff --git a/utils/hooks/30-add-offb.c b/utils/hooks/30-add-offb.c new file mode 100644 index 0000000..c635409 --- /dev/null +++ b/utils/hooks/30-add-offb.c @@ -0,0 +1,492 @@ + +#define _GNU_SOURCE + +#include <stdlib.h> +#include <err.h> +#include <fcntl.h> +#include <limits.h> +#include <sys/ioctl.h> +#include <string.h> +#include <stdbool.h> +#include <inttypes.h> + +#include <linux/fb.h> + +#include <libfdt.h> + +#include <file/file.h> +#include <talloc/talloc.h> + +static const char *fbdev_name = "fb0"; + +#define MAX_N_CELLS 4 +#define ADDRESS_PROP_SIZE 4096 + +struct offb_ctx { + const char *dtb_name; + void *dtb; + int dtb_node; + const char *path; + struct fb_fix_screeninfo fscreeninfo; + struct fb_var_screeninfo vscreeninfo; +}; + +static int load_dtb(struct offb_ctx *ctx) +{ + char *buf; + int len; + int rc; + + rc = read_file(ctx, ctx->dtb_name, &buf, &len); + if (rc) { + warn("error reading %s", ctx->dtb_name); + return rc; + } + + rc = fdt_check_header(buf); + if (rc || (int)fdt_totalsize(buf) > len) { + warnx("invalid dtb: %s (rc %d)", ctx->dtb_name, rc); + return -1; + } + + len = fdt_totalsize(buf) + ADDRESS_PROP_SIZE; + + ctx->dtb = talloc_array(ctx, char, len); + if (!ctx->dtb) { + warn("Failed to allocate space for dtb\n"); + return -1; + } + fdt_open_into(buf, ctx->dtb, len); + + return 0; +} + +static int fbdev_sysfs_lookup(struct offb_ctx *ctx) +{ + char *path, *linkpath, *nodepath; + int fd, node; + ssize_t rc __attribute__((unused)); + + path = talloc_asprintf(ctx, "/sys/class/graphics/%s", fbdev_name); + if (!path) { + warn("Failed to allocate space for sysfs path\n"); + return -1; + } + + fd = open(path, O_RDONLY | O_DIRECTORY); + if (fd < 0) { + warn("Can't open device %s in sysfs", fbdev_name); + return -1; + } + + linkpath = talloc_zero_array(ctx, char, PATH_MAX + 1); + if (!linkpath) { + warn("Failed to allocate space for link path\n"); + return -1; + } + + rc = readlinkat(fd, "device/of_node", linkpath, PATH_MAX); + if (rc < 0) { + warn("Can't read of_node link for device %s", fbdev_name); + return -1; + } + + /* readlinkat() returns a relative path such as: + * + * ../../../../../../../firmware/devicetree/base/pciex@n/…/vga@0 + * + * We only need the path component from the device tree itself; so + * strip everything before /firmware/devicetree/base + */ + nodepath = strstr(linkpath, "/firmware/devicetree/base/"); + if (!nodepath) { + warnx("Can't resolve device tree link for device %s", + fbdev_name); + return -1; + } + + nodepath += strlen("/firmware/devicetree/base"); + + node = fdt_path_offset(ctx->dtb, nodepath); + if (node < 0) { + warnx("Can't find node %s in device tree: %s", + nodepath, fdt_strerror(node)); + return -1; + } + + ctx->path = nodepath; + ctx->dtb_node = node; + + return 0; +} + +static int fbdev_device_query(struct offb_ctx *ctx) +{ + int fd, rc = -1; + char *path; + + path = talloc_asprintf(ctx, "/dev/%s", fbdev_name); + if (!path) { + warn("Failed to allocate space for device path\n"); + return -1; + } + + fd = open(path, O_RDWR); + if (fd < 0) { + warn("Can't open fb device %s", path); + return -1; + } + + rc = ioctl(fd, FBIOGET_VSCREENINFO, &ctx->vscreeninfo); + if (rc) { + warn("ioctl(FBIOGET_VSCREENINFO) failed"); + goto out; + } + + rc = ioctl(fd, FBIOGET_FSCREENINFO, &ctx->fscreeninfo); + if (rc) { + warn("ioctl(FBIOGET_FSCREENINFO) failed"); + goto out; + } + + fprintf(stderr, "Retrieved framebuffer details:\n"); + fprintf(stderr, "device %s:\n", fbdev_name); + fprintf(stderr, " addr: %lx\n", ctx->fscreeninfo.smem_start); + fprintf(stderr, " len: %" PRIu32 "\n", ctx->fscreeninfo.smem_len); + fprintf(stderr, " line: %d\n", ctx->fscreeninfo.line_length); + fprintf(stderr, " res: %dx%d@%d\n", ctx->vscreeninfo.xres, + ctx->vscreeninfo.yres, + ctx->vscreeninfo.bits_per_pixel); + + rc = 0; + +out: + close(fd); + return rc; +} + +static char *next_dt_name(struct offb_ctx *ctx, const char **path) +{ + const char *c, *p; + char *name; + + p = *path; + + if (p[0] == '/') + p++; + + if (p[0] == '\0') + return NULL; + + c = strchrnul(p, '/'); + + name = talloc_strndup(ctx, p, c - p); + + *path = c; + + return name; +} + +static uint64_t of_read_number(const fdt32_t *data, int n) +{ + uint64_t x; + + x = fdt32_to_cpu(data[0]); + if (n > 1) { + x <<= 32; + x |= fdt32_to_cpu(data[1]); + } + return x; +} + +/* Do a single translation across a PCI bridge. This results in either; + * - Translating a 2-cell CPU address into a 3-cell PCI address, or + * - Translating a 3-cell PCI address into a 3-cell PCI address with a + * different offset. + * + * To simplify translation we make some assumptions about addresses: + * Addresses are either 3 or 2 cells wide + * Size is always 2 cells wide + * The first cell of a 3 cell address is the PCI memory type + */ +static int do_translate(void *fdt, int node, + const fdt32_t *ranges, int range_size, + uint32_t *addr, uint32_t *size, + int *addr_cells, int *size_cells) +{ + uint64_t addr_current_base, addr_child_base, addr_size; + uint64_t addr_current, offset, new_addr; + uint64_t current_pci_flags, child_pci_flags; + int i, na, ns, cna, cns, prop_len; + const fdt32_t *prop; + const char *type; + bool pci = false; + + type = fdt_getprop(fdt, node, "device_type", NULL); + pci = type && (!strcmp(type, "pci") || !strcmp(type, "pciex")); + + /* We don't translate at vga@0, so we should always see a pci or + * pciex device_type */ + if (!pci) + return -1; + + if (range_size == 0) { + fprintf(stderr, "Empty ranges property, 1:1 translation\n"); + return 0; + } + + /* Number of cells for address and size at current level */ + na = *addr_cells; + ns = *size_cells; + + /* Number of cells for address and size at child level */ + prop = fdt_getprop(fdt, node, "#address-cells", &prop_len); + cna = prop ? fdt32_to_cpu(*prop) : 2; + prop = fdt_getprop(fdt, node, "#size-cells", &prop_len); + cns = prop ? fdt32_to_cpu(*prop) : 2; + + /* We're translating back to a PCI address, so the size should grow */ + if (na > cna) { + fprintf(stderr, "na > cna, unexpected\n"); + return -1; + } + + /* If the current address is a PCI address, its type should match the + * type of every subsequent child address */ + current_pci_flags = na > 2 ? of_read_number(addr, 1) : 0; + child_pci_flags = cna > 2 ? of_read_number(ranges, 1) : 0; + if (current_pci_flags != 0 && current_pci_flags != child_pci_flags) { + fprintf(stderr, "Unexpected change in flags: %lx, %lx\n", + current_pci_flags, child_pci_flags); + return -1; + } + + if (ns != cns) { + fprintf(stderr, "Unexpected change in #size-cells: %d vs %d\n", + ns, cns); + return -1; + } + + /* + * The ranges property is of the form + * < upstream addr base > < downstream addr base > < size > + * The current address stored in addr is similarly of the form + * < current address > < size > + * Where either address base and the current address can be a 2-cell + * CPU address or a 3-cell PCI address. + * + * For PCI addresses ignore the type flag in the first cell and use the + * 64-bit address in the remaining 2 cells. + */ + if (na > 2) { + addr_current_base = of_read_number(ranges + cna + 1, na - 1); + addr_current = of_read_number(addr + 1, na - 1); + } else { + addr_current_base = of_read_number(ranges + cna, na); + addr_current = of_read_number(addr, na); + } + if (cna > 2) + addr_child_base = of_read_number(ranges + 1, cna - 1); + else + addr_child_base = of_read_number(ranges, cna); + + /* + * Perform the actual translation. Find the offset of the current + * address from the upstream base, and add the offset to the + * downstream base to find the new address. + * The new address will be cna-cells wide, inheriting child_pci_flags + * as the memory type. + */ + addr_size = of_read_number(size, ns); + offset = addr_current - addr_current_base; + new_addr = addr_child_base + offset; + + memset(addr, 0, *addr_cells); + memset(size, 0, *size_cells); + *addr_cells = cna; + *size_cells = cns; + + /* Update the current address in addr. + * It's highly unlikely any translation will leave us with a 2-cell + * CPU address, but for completeness only include PCI flags if the + * child offset was definitely a PCI address */ + if (*addr_cells > 2) + addr[0] = cpu_to_fdt32(child_pci_flags); + for (i = *addr_cells - 1; i >= *addr_cells - 2; i--) { + addr[i] = cpu_to_fdt32(new_addr & 0xffffffff); + new_addr >>= 32; + } + for (i = *size_cells - 1; i >= 0; i--) { + size[i] = cpu_to_fdt32(addr_size & 0xffffffff); + addr_size >>= 32; + } + + fprintf(stderr, "New address:\n\t"); + for (i = 0; i < *addr_cells; i++) + fprintf(stderr, " %lx ", of_read_number(&addr[i], 1)); + fprintf(stderr, "\n"); + + return 0; +} + +static int create_translated_addresses(struct offb_ctx *ctx, + int dev_node, const char *path, + uint64_t in_addr, uint64_t in_size, + fdt32_t *reg, int reg_cells) +{ + uint32_t addr[MAX_N_CELLS], size[MAX_N_CELLS]; + int addr_cells, size_cells, node, prop_len, ranges_len, rc, i; + const fdt32_t *ranges, *prop; + char *name; + + prop = fdt_getprop(ctx->dtb, 0, "#address-cells", &prop_len); + addr_cells = prop ? fdt32_to_cpu(*prop) : 2; + + prop = fdt_getprop(ctx->dtb, 0, "#size-cells", &prop_len); + size_cells = prop ? fdt32_to_cpu(*prop) : 2; + + memset(addr, 0, sizeof(uint32_t) * MAX_N_CELLS); + for (i = addr_cells - 1; i >= 0; i--) { + addr[i] = cpu_to_fdt32(in_addr & 0xffffffff); + in_addr >>= 32; + } + memset(size, 0, sizeof(uint32_t) * MAX_N_CELLS); + for (i = size_cells - 1; i >= 0; i--) { + size[i] = cpu_to_fdt32(in_size & 0xffffffff); + in_size >>= 32; + } + + node = 0; + for (;;) { + /* get the name of the next child node to 'node' */ + name = next_dt_name(ctx, &path); + if (!name) + return -1; + + node = fdt_subnode_offset(ctx->dtb, node, name); + if (node < 0) + return -1; + if (node == dev_node) + break; + + ranges = fdt_getprop(ctx->dtb, node, "ranges", &ranges_len); + if (!ranges) + return -1; + + rc = do_translate(ctx->dtb, node, ranges, ranges_len, + addr, size, &addr_cells, &size_cells); + if (rc) + return -1; + } + + fprintf(stderr, "Final address:\n\t"); + for (i = 0; i < addr_cells; i++) + fprintf(stderr, " %lx ", of_read_number(&addr[i], 1)); + fprintf(stderr, "\n"); + + if (addr_cells + size_cells > reg_cells) { + fprintf(stderr, "Error: na + ns larger than reg\n"); + return -1; + } + + memcpy(reg, addr, sizeof(fdt32_t) * addr_cells); + memcpy(reg + addr_cells, size, sizeof(fdt32_t) * size_cells); + + return 0; +} + +#define fdt_set_check(dtb, node, fn, prop, ...) \ + do { \ + int __x = fn(dtb, node, prop, __VA_ARGS__); \ + if (__x) { \ + warnx("failed to update device tree (%s): %s", \ + prop, fdt_strerror(__x)); \ + return -1; \ + } \ + } while (0); + +static int populate_devicetree(struct offb_ctx *ctx) +{ + fdt32_t reg[5]; + void *dtb = ctx->dtb; + int rc, node = ctx->dtb_node; + + memset(reg, 0, sizeof(reg)); + rc = create_translated_addresses(ctx, node, ctx->path, + ctx->fscreeninfo.smem_start, + ctx->fscreeninfo.smem_len, + reg, 5); + + if (rc) { + fprintf(stderr, "Failed to translate address\n"); + return rc; + } + + fdt_set_check(dtb, node, fdt_setprop_string, "device_type", "display"); + + fdt_set_check(dtb, node, fdt_setprop, "assigned-addresses", + reg, sizeof(reg)); + + fdt_set_check(dtb, node, fdt_setprop_cell, + "width", ctx->vscreeninfo.xres); + fdt_set_check(dtb, node, fdt_setprop_cell, + "height", ctx->vscreeninfo.yres); + fdt_set_check(dtb, node, fdt_setprop_cell, + "depth", ctx->vscreeninfo.bits_per_pixel); + + fdt_set_check(dtb, node, fdt_setprop, "little-endian", NULL, 0); + fdt_set_check(dtb, node, fdt_setprop, "linux,opened", NULL, 0); + fdt_set_check(dtb, node, fdt_setprop, "linux,boot-display", NULL, 0); + + return 0; +} + +static int write_devicetree(struct offb_ctx *ctx) +{ + int rc; + + fdt_pack(ctx->dtb); + + rc = replace_file(ctx->dtb_name, ctx->dtb, fdt_totalsize(ctx->dtb)); + if (rc) + warn("failed to write file %s", ctx->dtb_name); + + return rc; +} + + +int main(void) +{ + struct offb_ctx *ctx; + int rc; + + ctx = talloc_zero(NULL, struct offb_ctx); + + ctx->dtb_name = getenv("boot_dtb"); + if (!ctx->dtb_name) { + talloc_free(ctx); + return EXIT_SUCCESS; + } + + rc = load_dtb(ctx); + if (rc) + goto out; + + rc = fbdev_sysfs_lookup(ctx); + if (rc) + goto out; + + rc = fbdev_device_query(ctx); + if (rc) + goto out; + + rc = populate_devicetree(ctx); + if (rc) + goto out; + + rc = write_devicetree(ctx); + +out: + talloc_free(ctx); + return rc ? EXIT_FAILURE : EXIT_SUCCESS; +} |
