Date: Mon, 1 May 2023 21:28:50 GMT From: Warner Losh <imp@FreeBSD.org> To: src-committers@FreeBSD.org, dev-commits-src-all@FreeBSD.org, dev-commits-src-main@FreeBSD.org Subject: git: a083d0867635 - main - kboot: Add smbios support Message-ID: <202305012128.341LSono085919@gitrepo.freebsd.org>
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The branch main has been updated by imp: URL: https://cgit.FreeBSD.org/src/commit/?id=a083d086763594a7072b11fd9ef0553c6466da34 commit a083d086763594a7072b11fd9ef0553c6466da34 Author: Warner Losh <imp@FreeBSD.org> AuthorDate: 2023-05-01 21:12:29 +0000 Commit: Warner Losh <imp@FreeBSD.org> CommitDate: 2023-05-01 21:12:29 +0000 kboot: Add smbios support Add support for getting smbios from /sys/firmware/efi/systab, if any. Add ptov mapping that uses mmap on /dev/mem to do the mapping with 64k pages (usually we only need 1 or two mappings). Sponsored by: Netflix Differential Revision: https://reviews.freebsd.org/D39792 --- stand/kboot/main.c | 107 ++++++++++++++++++++++++++++++++++++++++++++++++++++- 1 file changed, 106 insertions(+), 1 deletion(-) diff --git a/stand/kboot/main.c b/stand/kboot/main.c index ecf96cc73d4d..c8c49067bcc7 100644 --- a/stand/kboot/main.c +++ b/stand/kboot/main.c @@ -36,6 +36,7 @@ __FBSDID("$FreeBSD$"); #include "host_syscall.h" #include "kboot.h" #include "stand.h" +#include <smbios.h> struct arch_switch archsw; extern void *_end; @@ -195,6 +196,107 @@ has_acpi(void) return rsdp != 0; } +/* + * SMBIOS support. We map the physical memory address we get into a VA in this + * address space with mmap with 64k pages. Once we're done, we cleanup any + * mappings we made. + */ + +#define MAX_MAP 10 +#define PAGE (64<<10) + +static struct mapping +{ + uintptr_t pa; + caddr_t va; +} map[MAX_MAP]; +static int smbios_fd; +static int nmap; + +caddr_t ptov(uintptr_t pa) +{ + caddr_t va; + uintptr_t pa2; + struct mapping *m = map; + + pa2 = rounddown(pa, PAGE); + for (int i = 0; i < nmap; i++, m++) { + if (m->pa == pa2) { + return (m->va + pa - m->pa); + } + } + if (nmap == MAX_MAP) + panic("Too many maps for smbios"); + + /* + * host_mmap returns small negative numbers on errors, can't return an + * error here, so we have to panic. The Linux wrapper will set errno + * based on this and then return HOST_MAP_FAILED. Since we're calling + * the raw system call we have to do that ourselves. + */ + va = host_mmap(0, PAGE, HOST_PROT_READ, HOST_MAP_SHARED, smbios_fd, pa2); + if ((intptr_t)va < 0 && (intptr_t)va >= -511) + panic("smbios mmap offset %#jx failed", (uintmax_t)pa2); + m = &map[nmap++]; + m->pa = pa2; + m->va = va; + return (m->va + pa - m->pa); +} + +static void +smbios_cleanup(void) +{ + for (int i = 0; i < nmap; i++) { + host_munmap(map[i].va, PAGE); + } +} + +static vm_offset_t +kboot_find_smbios(void) +{ + char buffer[512 + 1]; + char *walker, *ep; + + if (!file2str("/sys/firmware/efi/systab", buffer, sizeof(buffer))) + return (0); /* Not an EFI system */ + ep = buffer + strlen(buffer); + walker = buffer; + while (walker <= ep) { + if (strncmp("SMBIOS3=", walker, 8) == 0) + return((vm_offset_t)strtoull(walker + 8, NULL, 0)); + if (strncmp("SMBIOS=", walker, 7) == 0) + return((vm_offset_t)strtoull(walker + 7, NULL, 0)); + walker += strcspn(walker, "\n") + 1; + } + return (0); +} + +static void +find_smbios(void) +{ + char buf[40]; + uintptr_t pa; + caddr_t va; + + pa = kboot_find_smbios(); + printf("SMBIOS at %#jx\n", (uintmax_t)pa); + if (pa == 0) + return; + + snprintf(buf, sizeof(buf), "%#jx", (uintmax_t)pa); + setenv("hint.smbios.0.mem", buf, 1); + smbios_fd = host_open("/dev/mem", O_RDONLY, 0); + if (smbios_fd < 0) { + printf("Can't open /dev/mem to read smbios\n"); + return; + } + va = ptov(pa); + printf("Start of smbios at pa %p va %p\n", (void *)pa, va); + smbios_detect(va); + smbios_cleanup(); + host_close(smbios_fd); +} + static void parse_file(const char *fn) { @@ -300,6 +402,8 @@ main(int argc, const char **argv) */ find_acpi(); + find_smbios(); + interact(); /* doesn't return */ return (0); @@ -531,5 +635,6 @@ command_fdt(int argc, char *argv[]) return (command_fdt_internal(argc, argv)); } - + COMMAND_SET(fdt, "fdt", "flattened device tree handling", command_fdt); +
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