fw: Simplify logic

Switch on state, then read commands specifically in the states that
allow reading of commands, then switch on specific command.
This commit is contained in:
Michael Cardell Widerkrantz 2023-03-09 14:11:43 +01:00 committed by Daniel Lublin
parent 7a97f1ee5f
commit 4e3f5469ef
No known key found for this signature in database
GPG Key ID: 75BD0FEB8D3E7830
4 changed files with 206 additions and 196 deletions

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@ -9,6 +9,7 @@
#include "led.h"
#include "lib.h"
#include "proto.h"
#include "state.h"
#include "types.h"
// clang-format off
@ -140,14 +141,6 @@ static void compute_cdi(uint8_t digest[32], uint8_t use_uss, uint8_t uss[32])
wordcpy_s((void *)cdi, 8, local_cdi, 8);
}
enum state {
FW_STATE_INITIAL,
FW_STATE_LOADING,
FW_STATE_RUN,
FW_STATE_FAIL,
FW_STATE_MAX,
};
int main()
{
// Set RAM address and data scrambling values
@ -180,30 +173,172 @@ int main()
enum state state = FW_STATE_INITIAL;
// Let the app know the function adddress for blake2s()
*fw_blake2s_addr = (uint32_t)blake2s;
const uint32_t command_allowed[FW_STATE_MAX] = {
// FW_STATE_INITIAL
1 << FW_CMD_NAME_VERSION |
1 << FW_CMD_LOAD_APP |
1 << FW_CMD_GET_UDI,
// FW_STATE_LOADING
1 << FW_CMD_NAME_VERSION |
0 << FW_CMD_LOAD_APP |
1 << FW_CMD_LOAD_APP_DATA |
1 << FW_CMD_GET_UDI,
// FW_STATE_RUN
0,
// FW_STATE_FAIL
0,
};
print_hw_version(namever);
for (;;) {
switch (state) {
case FW_STATE_INITIAL:
if (readcommand(&hdr, cmd, state) == -1) {
state = FW_STATE_FAIL;
break;
}
// Reset response buffer
memset(rsp, 0, CMDLEN_MAXBYTES);
switch (cmd[0]) {
case FW_CMD_NAME_VERSION:
htif_puts("cmd: name-version\n");
if (hdr.len != 1) {
// Bad length - give them an empty
// response
fwreply(hdr, FW_RSP_NAME_VERSION, rsp);
break;
}
memcpy_s(rsp, CMDLEN_MAXBYTES, &namever.name0,
4);
memcpy_s(&rsp[4], CMDLEN_MAXBYTES - 4,
&namever.name1, 4);
memcpy_s(&rsp[8], CMDLEN_MAXBYTES - 8,
&namever.version, 4);
htif_hexdump(rsp, 12);
fwreply(hdr, FW_RSP_NAME_VERSION, rsp);
// state unchanged
break;
case FW_CMD_GET_UDI:
htif_puts("cmd: get-udi\n");
if (hdr.len != 1) {
// Bad cmd length
rsp[0] = STATUS_BAD;
fwreply(hdr, FW_RSP_GET_UDI, rsp);
break;
}
rsp[0] = STATUS_OK;
uint32_t udi_words[2];
wordcpy_s(udi_words, 2, (void *)udi, 2);
memcpy_s(&rsp[1], CMDLEN_MAXBYTES - 1,
udi_words, 2 * 4);
fwreply(hdr, FW_RSP_GET_UDI, rsp);
// state unchanged
break;
case FW_CMD_LOAD_APP:
htif_puts("cmd: load-app(size, uss)\n");
if (hdr.len != 512) {
// Bad length
rsp[0] = STATUS_BAD;
fwreply(hdr, FW_RSP_LOAD_APP, rsp);
break;
}
// cmd[1..4] contains the size.
uint32_t local_app_size =
cmd[1] + (cmd[2] << 8) + (cmd[3] << 16) +
(cmd[4] << 24);
htif_puts("app size: ");
htif_putinthex(local_app_size);
htif_lf();
if (local_app_size == 0 ||
local_app_size > TK1_APP_MAX_SIZE) {
rsp[0] = STATUS_BAD;
fwreply(hdr, FW_RSP_LOAD_APP, rsp);
break;
}
*app_size = local_app_size;
// Do we have a USS at all?
if (cmd[5] != 0) {
// Yes
use_uss = TRUE;
memcpy_s(uss, 32, &cmd[6], 32);
} else {
use_uss = FALSE;
}
rsp[0] = STATUS_OK;
fwreply(hdr, FW_RSP_LOAD_APP, rsp);
assert(*app_size != 0);
assert(*app_size <= TK1_APP_MAX_SIZE);
left = *app_size;
state = FW_STATE_LOADING;
break;
}
break;
case FW_STATE_LOADING:
if (readcommand(&hdr, cmd, state) == -1) {
state = FW_STATE_FAIL;
break;
}
// Reset response buffer
memset(rsp, 0, CMDLEN_MAXBYTES);
switch (cmd[0]) {
case FW_CMD_LOAD_APP_DATA:
htif_puts("cmd: load-app-data\n");
if (hdr.len != 512) {
// Bad cmd length
rsp[0] = STATUS_BAD;
fwreply(hdr, FW_RSP_LOAD_APP_DATA, rsp);
break;
}
int nbytes;
if (left > (512 - 1)) {
nbytes = 512 - 1;
} else {
nbytes = left;
}
memcpy_s(loadaddr, left, cmd + 1, nbytes);
loadaddr += nbytes;
left -= nbytes;
if (left == 0) {
htif_puts("Fully loaded ");
htif_putinthex(*app_size);
htif_lf();
// Compute Blake2S digest of the app,
// storing it for FW_STATE_RUN
blake2s_ctx ctx;
blake2s(digest, 32, NULL, 0,
(const void *)TK1_RAM_BASE,
*app_size, &ctx);
print_digest(digest);
// And return the digest in final
// response
rsp[0] = STATUS_OK;
memcpy_s(&rsp[1], CMDLEN_MAXBYTES - 1,
&digest, 32);
fwreply(hdr, FW_RSP_LOAD_APP_DATA_READY,
rsp);
state = FW_STATE_RUN;
break;
}
rsp[0] = STATUS_OK;
fwreply(hdr, FW_RSP_LOAD_APP_DATA, rsp);
break;
default:
htif_puts("Got unknown firmware cmd: 0x");
htif_puthex(cmd[0]);
htif_lf();
state = FW_STATE_FAIL;
}
break;
case FW_STATE_RUN:
@ -257,177 +392,6 @@ int main()
forever_redflash();
break; // Not reached
}
uint8_t in;
*led = (state == FW_STATE_LOADING) ? LED_BLACK : LED_WHITE;
in = readbyte();
if (parseframe(in, &hdr) == -1) {
htif_puts("Couldn't parse header\n");
state = FW_STATE_FAIL;
continue;
}
memset(cmd, 0, CMDLEN_MAXBYTES);
// Now we know the size of the cmd frame, read it all
if (read(cmd, CMDLEN_MAXBYTES, hdr.len) != 0) {
htif_puts("read: buffer overrun\n");
state = FW_STATE_FAIL;
continue;
}
// Is it for us?
if (hdr.endpoint != DST_FW) {
htif_puts("Message not meant for us\n");
state = FW_STATE_FAIL;
continue;
}
// Reset response buffer
memset(rsp, 0, CMDLEN_MAXBYTES);
// Min length is 1 byte so cmd[0] should always be here
// Is this command allowed in current state?
assert(command_allowed[state] & (1 << cmd[0]));
switch (cmd[0]) {
case FW_CMD_NAME_VERSION:
htif_puts("cmd: name-version\n");
if (hdr.len != 1) {
// Bad length - give them an empty response
fwreply(hdr, FW_RSP_NAME_VERSION, rsp);
break;
}
memcpy_s(rsp, CMDLEN_MAXBYTES, &namever.name0, 4);
memcpy_s(&rsp[4], CMDLEN_MAXBYTES - 4, &namever.name1,
4);
memcpy_s(&rsp[8], CMDLEN_MAXBYTES - 8, &namever.version,
4);
fwreply(hdr, FW_RSP_NAME_VERSION, rsp);
// state unchanged
break;
case FW_CMD_GET_UDI:
htif_puts("cmd: get-udi\n");
if (hdr.len != 1) {
// Bad cmd length
rsp[0] = STATUS_BAD;
fwreply(hdr, FW_RSP_GET_UDI, rsp);
break;
}
rsp[0] = STATUS_OK;
uint32_t udi_words[2];
wordcpy_s(udi_words, 2, (void *)udi, 2);
memcpy_s(&rsp[1], CMDLEN_MAXBYTES - 1, udi_words,
2 * 4);
fwreply(hdr, FW_RSP_GET_UDI, rsp);
// state unchanged
break;
case FW_CMD_LOAD_APP:
htif_puts("cmd: load-app(size, uss)\n");
if (hdr.len != 512) {
// Bad length
rsp[0] = STATUS_BAD;
fwreply(hdr, FW_RSP_LOAD_APP, rsp);
break;
}
// cmd[1..4] contains the size.
uint32_t local_app_size = cmd[1] + (cmd[2] << 8) +
(cmd[3] << 16) +
(cmd[4] << 24);
htif_puts("app size: ");
htif_putinthex(local_app_size);
htif_lf();
if (local_app_size == 0 ||
local_app_size > TK1_APP_MAX_SIZE) {
rsp[0] = STATUS_BAD;
fwreply(hdr, FW_RSP_LOAD_APP, rsp);
break;
}
*app_size = local_app_size;
// Do we have a USS at all?
if (cmd[5] != 0) {
// Yes
use_uss = TRUE;
memcpy_s(uss, 32, &cmd[6], 32);
} else {
use_uss = FALSE;
}
rsp[0] = STATUS_OK;
fwreply(hdr, FW_RSP_LOAD_APP, rsp);
assert(*app_size != 0);
assert(*app_size <= TK1_APP_MAX_SIZE);
*app_addr = 0;
left = *app_size;
state = FW_STATE_LOADING;
break;
case FW_CMD_LOAD_APP_DATA:
htif_puts("cmd: load-app-data\n");
if (hdr.len != 512) {
// Bad cmd length
rsp[0] = STATUS_BAD;
fwreply(hdr, FW_RSP_LOAD_APP_DATA, rsp);
break;
}
int nbytes;
if (left > (512 - 1)) {
nbytes = 512 - 1;
} else {
nbytes = left;
}
memcpy_s(loadaddr, left, cmd + 1, nbytes);
loadaddr += nbytes;
left -= nbytes;
if (left == 0) {
htif_puts("Fully loaded ");
htif_putinthex(*app_size);
htif_lf();
// Compute Blake2S digest of the app, storing
// it for FW_STATE_RUN
blake2s_ctx ctx;
blake2s(digest, 32, NULL, 0,
(const void *)TK1_RAM_BASE, *app_size,
&ctx);
print_digest(digest);
// And return the digest in final response
rsp[0] = STATUS_OK;
memcpy_s(&rsp[1], CMDLEN_MAXBYTES - 1, &digest,
32);
fwreply(hdr, FW_RSP_LOAD_APP_DATA_READY, rsp);
state = FW_STATE_RUN;
break;
}
rsp[0] = STATUS_OK;
fwreply(hdr, FW_RSP_LOAD_APP_DATA, rsp);
break;
default:
htif_puts("Got unknown firmware cmd: 0x");
htif_puthex(cmd[0]);
htif_lf();
state = FW_STATE_FAIL;
}
}
return (int)0xcafebabe;

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@ -5,7 +5,9 @@
#include "proto.h"
#include "../tk1_mem.h"
#include "led.h"
#include "lib.h"
#include "state.h"
#include "types.h"
// clang-format off
@ -20,6 +22,34 @@ uint8_t genhdr(uint8_t id, uint8_t endpoint, uint8_t status, enum cmdlen len)
return (id << 5) | (endpoint << 3) | (status << 2) | len;
}
int readcommand(struct frame_header *hdr, uint8_t *cmd, int state)
{
uint8_t in;
*led = (state == FW_STATE_LOADING) ? LED_BLACK : LED_WHITE;
in = readbyte();
if (parseframe(in, hdr) == -1) {
htif_puts("Couldn't parse header\n");
return -1;
}
memset(cmd, 0, CMDLEN_MAXBYTES);
// Now we know the size of the cmd frame, read it all
if (read(cmd, CMDLEN_MAXBYTES, hdr->len) != 0) {
htif_puts("read: buffer overrun\n");
return -1;
}
// Is it for us?
if (hdr->endpoint != DST_FW) {
htif_puts("Message not meant for us\n");
return -1;
}
return 0;
}
int parseframe(uint8_t b, struct frame_header *hdr)
{
if ((b & 0x80) != 0) {

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@ -57,5 +57,5 @@ void writebyte(uint8_t b);
void write(uint8_t *buf, size_t nbytes);
uint8_t readbyte();
int read(uint8_t *buf, size_t bufsize, size_t nbytes);
int readcommand(struct frame_header *hdr, uint8_t *cmd, int state);
#endif

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@ -0,0 +1,16 @@
/*
* Copyright (C) 2023 - Tillitis AB
* SPDX-License-Identifier: GPL-2.0-only
*/
#ifndef STATE_H
#define STATE_H
enum state {
FW_STATE_INITIAL,
FW_STATE_LOADING,
FW_STATE_RUN,
FW_STATE_FAIL,
FW_STATE_MAX,
};
#endif