@@ -27,7 +27,8 @@ asm (".code32"); /* this code will be executed in protected mode */
#include "optrom_fw_cfg.h"
#include "../../include/hw/xen/start_info.h"
-#define RSDP_SIGNATURE 0x2052545020445352LL /* "RSD PTR " */
+#define RSDP_SIGNATURE "RSD PTR "
+#define RSDP_SIGNATURE_SIZE 8
#define RSDP_AREA_ADDR 0x000E0000
#define RSDP_AREA_SIZE 0x00020000
#define EBDA_BASE_ADDR 0x0000040E
@@ -53,12 +54,13 @@ static uint8_t cmdline_buffer[CMDLINE_BUFSIZE];
/* Search RSDP signature. */
static uintptr_t search_rsdp(uint32_t start_addr, uint32_t end_addr)
{
- uint64_t *rsdp_p;
+ static const char rsdp_signature[RSDP_SIGNATURE_SIZE] = RSDP_SIGNATURE;
+ char *rsdp_p;
/* RSDP signature is always on a 16 byte boundary */
- for (rsdp_p = (uint64_t *)start_addr; rsdp_p < (uint64_t *)end_addr;
- rsdp_p += 2) {
- if (*rsdp_p == RSDP_SIGNATURE) {
+ for (rsdp_p = (char *)start_addr; rsdp_p < (char *)end_addr;
+ rsdp_p += 16) {
+ if (memcmp(rsdp_p, rsdp_signature, RSDP_SIGNATURE_SIZE) == 0) {
return (uintptr_t)rsdp_p;
}
}
New versions of gcc report a potential error and there may be alignment issues using uint64_t pointer to check the RSDP signature: gcc 10.2.1 "cc (Alpine 10.2.1_pre2) 10.2.1 20210313" reports: pc-bios/optionrom/pvh_main.c: In function 'search_rsdp': pc-bios/optionrom/pvh_main.c:61:21: warning: comparison is always false due to limited range of data type [-Wtype-limits] 61 | if (*rsdp_p == RSDP_SIGNATURE) { | ^~ Let's use memcmp() to get more readable code and avoid these issues. Reported-by: Philippe Mathieu-Daudé <philmd@redhat.com> Suggested-by: Paolo Bonzini <pbonzini@redhat.com> Signed-off-by: Stefano Garzarella <sgarzare@redhat.com> --- Notes: v2: - made 'rsdp_signature' static const [Phil] - uses memcmp() instead of __builtin_memcmp() - added pvh.bin binary with the changes applied pc-bios/optionrom/pvh_main.c | 12 +++++++----- pc-bios/pvh.bin | Bin 1536 -> 1536 bytes 2 files changed, 7 insertions(+), 5 deletions(-) diff --git a/pc-bios/pvh.bin b/pc-bios/pvh.bin index 8033080ada2db4c4613fdc3bb5a69d79c7b0c0ca..778ca261447bed794ecb98bb29138a09568aca67 100644 GIT binary patch delta 656 zcmZqRY2cYKnJIyF;?!q6oi`3X5NJNZ#ebrcWpX>CZ@rI-$Z^&MiVO@DNArx2vn~O$ z7#SEC7ACMVFf6_R<n71+u}%P4$63z+Nf6k<z`)1wny>kQfGq=q00V!^C7@uVMNqJd zLg}l<3YLJ7AcfM0iw}S`9f4}v*C5Ei&}pJ_+(m^2WJvQvCjM5&&dJ-D>^OD+)pUyP zQJnmTNsf)bbrDc{vJA6qJ;-6*J}MmlA2uJ6iH?hpJ=|LcbO*>_5ID{XGu-e%+Cn~{ zv7LtwK4NM9;lSUf^8f$;Zl>M|3_wxK3q_(YRT&u=dP~$8CIFpnd4a!K6v&6V`7O-N zPYf@CUEL`PGWaFygMa`3r%ldhHmq*|@{hB&07($&c2N;o+yNHqfeP&asaU)LEVczI zcARw$ki`hp@bVSVq~0xRAkAP$>;#3uE)fvdMMdC6?q8s5eN+T?i2_ABKfH(q@mW;5 zLsVE6g94`>6gmtH5MA65T_P_mK&nDiL|QME8bG83AW|GJWPwsICm}4IV0hr=R|Ge0 z0z^F*L_N=ow|~G65ZNUJ6ajjV=f!Q12#~QD<S_?I{GJ4iip?Kc_!uX#Dl@(T0NEhW AtpET3 delta 702 zcmZqRY2cYKndyM&#Hr7C4n7v>yw!Y)i~m%o$mDiL-})F8k>jilq6`cbNArx2v$g<P zj0_A63l9Jpi#Gs?9VbAn6+q%R>lz>l0y`KO_!!bAbPF_o3JP{n==NY~{1^}tq`-NR zzeOFWz4?HEEdvK1L+Rb)tP7xej<YU-vJ4NTE#zZiU^w`I#kQUS$S8B~X6W4jVp$$5 z7kin;#K6$I4P+0{9Lr<;ZJ|H`EOwPXFub%FWPGP6$mrfOhJ6XFK%R-paTgV!VL<(l znfP1HfezX$0F>Av0u<_emG*wOAdt5cq@s6n0h1EP46qq<L?_Q;l4B|jnY@ol)(jLR z-99QD{~tCVk%^9rk3HO5qQ)=*Y#+iaFKzz+|KGbs4P+TeesVmsVSNHn>v7f;APEB9 zE-E66Gr&SQP@x?l6^kc;#il^Tj<favS)ibQX@P3y1h7kYfgIoKq9X7j_V54yK$i*Z z0_p7h@WL0wXHn@6QDIpO@=1NC=o}yg(ZvnXCGtW8q$)&3r1ersCPa!0BE|E97h<5u zE+L=@(78M>e*Xa~1~L|t;}tic=V5+<*dze4iQ~l*pt�{~>}55^@s^51_>4%RN9B MZNA7N&B#~{07`n#VE_OC