mcc
mcc is a machine code compiler.
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tree 3d5e55f9d2ee3fb466f125d93b47cdfdb858f482 parent 700d4c4b5b2021938fa7380afe9497a92f06bb9d author esote <esote.net@gmail.com> 1560709515 -0500 committer esote <esote.net@gmail.com> 1560709515 -0500 gpgsig -----BEGIN PGP SIGNATURE----- iHUEABYIAB0WIQTXAxYDuIzimYoNSPuhTmRAjzzC8gUCXSArKAAKCRChTmRAjzzC 8gh7AQC1sU6y0K53c8Agqyjo1CSKOYgZLih32D4QOiZmlbTo3gEA1jnqPvDYRzJn 1SHJDaMKiF1ir091MQOMWjxpf9hxzgc= =LHpr -----END PGP SIGNATURE----- Options for custom bss and text addresses
README | 8 ++++--- mcc.1 | 8 +++++++ mcc.c | 80 +++++++++++++++++++++++++++++++++++++++++++++++------------------- 3 files changed, 70 insertions(+), 26 deletions(-)
diff --git a/README b/README
index d0ce109..f86604b 100644
--- a/README
+++ b/README
@@ -2,7 +2,7 @@ NAME
mcc - machine code compiler
SYNOPSIS
- mcc [-3s] [-m memsize] [-o file] file
+ mcc [-3s] [-b addr] [-m memsize] [-o file] [-t addr] file
DESCRIPTION
mcc is a machine code compiler. It reads ASCII text '0' and '1' mapping
@@ -22,8 +22,10 @@ DESCRIPTION
In 64-bit mode the .bss and .text sections start at 0x402000 and
0x401000 respectively, and in 32-bit mode 0x804a000 and 0x8049000
- respectively. Program header segment alignment is set to 0x1000 (the
- page size on most systems).
+ respectively. Use the -b and -t options to specify custom addresses.
+
+ Program header segment alignment is set to 0x1000 (the page size on most
+ systems).
.bss is aligned to a 16-byte constraint and .text to an 8-byte
constraint.
diff --git a/mcc.1 b/mcc.1
index 24fd57a..6cc99ec 100644
--- a/mcc.1
+++ b/mcc.1
@@ -23,8 +23,10 @@
.Sh SYNOPSIS
.Nm mcc
.Op Fl 3s
+.Op Fl b Ar addr
.Op Fl m Ar memsize
.Op Fl o Ar file
+.Op Fl t Ar addr
file
.Sh DESCRIPTION
.Nm mcc
@@ -54,6 +56,12 @@ executable.
In 64-bit mode the .bss and .text sections start at 0x402000 and
0x401000 respectively, and in 32-bit mode 0x804a000 and 0x8049000
respectively.
+Use the
+.Fl b
+and
+.Fl t
+options to specify custom addresses.
+.Pp
Program header segment alignment is set to 0x1000 (the page size on most
systems).
.Pp
diff --git a/mcc.c b/mcc.c
index 4f78314..a17f2e0 100644
--- a/mcc.c
+++ b/mcc.c
@@ -43,36 +43,48 @@ main(int argc, char *argv[])
char *end;
char const *iname;
char const *oname;
- uint64_t len;
- uint64_t mem;
- int use_64;
int ch;
+ int use_64;
+ int use_bss_addr;
+ int use_text_addr;
opts.self_m = 0;
+ opts.mem.n64 = 0;
+ opts.bss_vaddr.n64 = 0x402000;
+ opts.text_vaddr.n64 = 0x401000;
oname = "a.out";
- mem = 0;
/* default 64-bit */
use_64 = 1;
- opts.bss_vaddr.n64 = 0x402000;
- opts.text_vaddr.n64 = 0x401000;
- while ((ch = getopt(argc, argv, "3m:o:s")) != -1) {
+ use_bss_addr = 0;
+ use_text_addr = 0;
+
+ while ((ch = getopt(argc, argv, "3b:m:o:st:")) != -1) {
switch (ch) {
case '3':
use_64 = 0;
- opts.bss_vaddr.n32 = 0x804a000;
- opts.text_vaddr.n32 = 0x8049000;
+ break;
+ case 'b':
+ opts.bss_vaddr.n64 = strtoull(optarg, &end, 0);
+
+ if (errno == EINVAL || errno == ERANGE) {
+ err(1, "bss address invalid");
+ } else if (optarg == end) {
+ err(1, "no bss address read");
+ }
+
+ use_bss_addr = 1;
break;
case 'm':
- mem = strtoull(optarg, &end, 10);
+ opts.mem.n64 = strtoull(optarg, &end, 10);
if (errno == EINVAL || errno == ERANGE) {
err(1, "memsize invalid");
} else if (optarg == end) {
errx(1, "no memsize read");
- } else if (mem == 0) {
+ } else if (opts.mem.n64 == 0) {
warnx("if memsize is zero no .bss section will "
"be written");
}
@@ -84,18 +96,26 @@ main(int argc, char *argv[])
case 's':
opts.self_m = 1;
break;
+ case 't':
+ opts.text_vaddr.n64 = strtoull(optarg, &end, 0);
+
+ if (errno == EINVAL || errno == ERANGE) {
+ err(1, "text address invalid");
+ } else if (optarg == end) {
+ err(1, "no text address read");
+ }
+
+ use_text_addr = 1;
+ break;
default:
(void)fprintf(stderr,
- "usage: %s [-3s] [-m memsize] [-o file] file\n",
+ "usage: %s [-3s] [-b addr] [-m memsize] "
+ "[-o file] [-t addr] file\n",
argv[0]);
return 1;
}
}
- if (!use_64 && mem > UINT32_MAX) {
- warnx("memsize may overflow");
- }
-
argv += optind;
if ((iname = *argv) == NULL) {
@@ -110,20 +130,34 @@ main(int argc, char *argv[])
err(1, "open out");
}
- len = byte_len(in);
+ opts.len.n64 = byte_len(in);
+
+ if (!use_64) {
+ if (opts.mem.n64 > UINT32_MAX) {
+ warnx("memsize is larger than 32 bits");
+ }
+
+ if (opts.len.n64 > UINT32_MAX) {
+ warnx("input file byte length is larger than 32 bits");
+ }
+
+ if (!use_bss_addr) {
+ opts.bss_vaddr.n32 = 0x804a000;
+ } else if (opts.bss_vaddr.n64 > UINT32_MAX) {
+ warnx("bss address is larger than 32 bits");
+ }
- if (!use_64 && len > UINT32_MAX) {
- warnx("input file byte length may overflow");
+ if (!use_text_addr) {
+ opts.text_vaddr.n32 = 0x8049000;
+ } else if (opts.text_vaddr.n64 > UINT32_MAX) {
+ warnx("text address is larger than 32 bits");
+ }
}
if (use_64) {
- opts.mem.n64 = mem;
- opts.len.n64 = len;
write_ehdr64(out, &opts);
write_phdr64_text(out, &opts);
} else {
- opts.mem.n32 = (uint32_t)mem;
- opts.len.n32 = (uint32_t)len;
write_ehdr32(out, &opts);
write_phdr32_text(out, &opts);
}