Add helpers to disable the /secure-chosen/stdout-path property from a FDT to keep the secure-OS silent. This is useful to keep the console on for development purpose and off for the release case. For the later case, the board code also needs to ensure that no /chosen/stdout-path exsits, else the secure-OS may fallback to this node.
The API is very specific to make clear that only the /secure-chosen/stdout-path is patched on demand. Signed-off-by: Marco Felsch <[email protected]> --- include/pbl.h | 4 ++++ pbl/console.c | 18 ++++++++++++++++++ pbl/fdt.c | 26 ++++++++++++++++++++++++++ 3 files changed, 48 insertions(+) diff --git a/include/pbl.h b/include/pbl.h index 0961b6b91e585a59a3e8facb1af261857cb6f57e..7e64a9d200ade522ebeb6394c730b608abc6d2bf 100644 --- a/include/pbl.h +++ b/include/pbl.h @@ -17,6 +17,9 @@ extern unsigned long free_mem_end_ptr; void pbl_barebox_uncompress(void *dest, void *compressed_start, unsigned int len); int pbl_dtbz_uncompress(void *dest, void *compressed_start, unsigned long len); +void pbl_set_disable_secure_chosen_stdout(void); +int pbl_disable_secure_chosen_stdout(void); + void fdt_find_mem(const void *fdt, unsigned long *membase, unsigned long *memsize); int fdt_fixup_mem(void *fdt, unsigned long membase[], unsigned long memsize[], size_t num); @@ -34,6 +37,7 @@ int fdt_copy_node(const void *src_fdt, void *dest_fdt, const char *path, int pbl_barebox_verify(const void *compressed_start, unsigned int len, const void *hash, unsigned int hash_len); int pbl_load_fdt(const void *fdt, void *dest, int destsize); +int fdt_remove_secure_chosen_stdout(void *fdt); #endif diff --git a/pbl/console.c b/pbl/console.c index 66652320149db5cdb9d365c5b05a9ac0903935d2..b3f2ac60b5e23b487c0d098d5c2ac5c3f2c8acdc 100644 --- a/pbl/console.c +++ b/pbl/console.c @@ -4,6 +4,7 @@ #include <debug_ll.h> #include <asm/sections.h> #include <linux/err.h> +#include <pbl.h> /* * Put these in the data section so that they survive the clearing of the @@ -12,6 +13,23 @@ static __attribute__ ((section(".data"))) ulong putc_offset; static __attribute__ ((section(".data"))) void *putc_ctx; +/* + * No special segment handling required, since the value doesn't need to survive. + * The secure-os is loaded only once very early. Therefore this variable is + * checked only once too. + */ +static int disable_secure_chosen_stdout; + +void pbl_set_disable_secure_chosen_stdout(void) +{ + disable_secure_chosen_stdout = 1; +} + +int pbl_disable_secure_chosen_stdout(void) +{ + return disable_secure_chosen_stdout; +} + /** * pbl_set_putc() - setup UART used for PBL console * @putc: The putc function. diff --git a/pbl/fdt.c b/pbl/fdt.c index fa61c3c71298a2e036e0d324c09d452d8f0f7bbe..d8160e4a09867aab91dc89de5dc7b00dd08a4155 100644 --- a/pbl/fdt.c +++ b/pbl/fdt.c @@ -342,3 +342,29 @@ int fdt_copy_node(const void *src_fdt, void *dest_fdt, const char *path, return _fdt_copy_node(src_fdt, src_node, dest_fdt, dest_node); } + +int fdt_remove_secure_chosen_stdout(void *fdt) +{ + int sec_chosen; + int ret; + + if (!fdt) + return 0; + + sec_chosen = fdt_path_offset(fdt, "/secure-chosen"); + /* No secure-chosen node found, nothing to do */ + if (sec_chosen < 0) + return 0; + + ret = fdt_delprop(fdt, sec_chosen, "stdout-path"); + if (ret) { + if (ret == -FDT_ERR_NOTFOUND) + return 0; + + pr_warn("Failed to delete /secure-chosen/stdout-path with:%s\n", + fdt_strerror(ret)); + return -EINVAL; + } + + return 0; +} -- 2.47.3
